Stella 4t gas tank and switch
Moderator: Modern Buddy Staff
- pesce
- Member
- Posts: 106
- Joined: Wed Mar 16, 2011 3:02 am
- Location: Sacramento
Stella 4t gas tank and switch
So... it has happened to me 2x. About 1/2 gallon into a tank (50mi), i run out of gasoline (the gas gauge reads 3/4 full). I switch to aux and then I am good to go. When I get to the gas station, the tank looks pretty full and I can put 1/2 gallon into the tank and no more...
What do you think is happening? This only happens when I am in traffic or have some place to go, so I cant really examine what is going on.
Maybe a hose is wonky or the switch valve is messed up.
I may resort to just keeping the switch on aux/reserve the entire time.
Any suggestions?
What do you think is happening? This only happens when I am in traffic or have some place to go, so I cant really examine what is going on.
Maybe a hose is wonky or the switch valve is messed up.
I may resort to just keeping the switch on aux/reserve the entire time.
Any suggestions?
- Rippinyarn
- Member
- Posts: 652
- Joined: Tue Aug 08, 2006 9:35 pm
- Location: Royal Oak, Michigan
- Contact:
The next time it happens, stop and pull the gas cap. If you hear a 'whoosh' you might need to clear the hole in the gas cap in order to avoid the vacuum problems that have stricken some scoot. Failing that, you might have an obstruction somewhere in your fuel flow, either from the tank or valve, fuel line or maybe the carb. Can you tell us more about how it cuts out?
Edit: "hole", not "hold"
Edit: "hole", not "hold"
Last edited by Rippinyarn on Sat Mar 26, 2011 8:40 pm, edited 1 time in total.
Rovers SC
Check out the latest at scooterfile.com
Check out the latest at scooterfile.com
- bosco
- Dealer
- Posts: 103
- Joined: Sat Mar 20, 2010 11:56 pm
- Location: San Jose Ca.
- Contact:
yeah..
dont trust your gas gauge.
Think of it as a luxury not a necessity
you can probably get in there and bend the float to make it more accurate or have it swapped out under warranty but i GUARANTEE you will never be satisfied with its accuracy
The old p series that bike has been based on never had one until recently anyway
ride in the on position, when you run out switch to reserve and think about going to a gas station.
or just run reserve the whole time and look at your tank every time you take off for a ride. Eventually you will get a feel for your mileage and when you need to refuel.
a mileage test can help you too. Running your odometer as a gas gauge is way more accurate and effective.
dont trust your gas gauge.
Think of it as a luxury not a necessity
you can probably get in there and bend the float to make it more accurate or have it swapped out under warranty but i GUARANTEE you will never be satisfied with its accuracy
The old p series that bike has been based on never had one until recently anyway
ride in the on position, when you run out switch to reserve and think about going to a gas station.
or just run reserve the whole time and look at your tank every time you take off for a ride. Eventually you will get a feel for your mileage and when you need to refuel.
a mileage test can help you too. Running your odometer as a gas gauge is way more accurate and effective.
- BuddyRaton
- Scooter Dork
- Posts: 3887
- Joined: Sat Sep 09, 2006 10:08 pm
- Location: Boca Raton, Florida
- Contact:
bosco wrote:The old p series that bike has been based on never had one until recently anyway
ride in the on position, when you run out switch to reserve and think about going to a gas station.
And you WILL learn the coolest move to make on a Stella (or any other "classic" scooter)!
Run in the on position....motor dies...pull the clutch and shift into neutral...reach down and switch to reserve...pull the clutch...put it in gear and dump the clutch....keep on riding!
I don't recommend setting on reserve all the time...sooner or later it will happen that your out of gas with no reserve!
"Things fall apart - it's scientific" - David Byrne
www.teamscootertrash.com
'06 Cream Buddy 125, 11 Blur 220, 13 BMW C 650 GT, 68 Vespa SS180, 64 Vespa GS MK II, 65 Lambretta TV 175, 67 Vespa GT, 64 Vespa 150 VBB 64 Vespa GL
www.teamscootertrash.com
'06 Cream Buddy 125, 11 Blur 220, 13 BMW C 650 GT, 68 Vespa SS180, 64 Vespa GS MK II, 65 Lambretta TV 175, 67 Vespa GT, 64 Vespa 150 VBB 64 Vespa GL
- ericalm
- Site Admin
- Posts: 16842
- Joined: Sat Jun 10, 2006 3:01 am
- Location: Los Angeles, CA
- Contact:
I run in reserve all the time.
As I said in another post, I've gotten pretty good in knowing how long I can go on "E" before I really need to get gas. On my daily commute, this works fine, especially as I have gas stations along the way.
On a longer trip, it wouldn't be quite as smart. The good thing is that on group rides, everyone else runs low before I do so I just top off when we stop.

As I said in another post, I've gotten pretty good in knowing how long I can go on "E" before I really need to get gas. On my daily commute, this works fine, especially as I have gas stations along the way.
On a longer trip, it wouldn't be quite as smart. The good thing is that on group rides, everyone else runs low before I do so I just top off when we stop.
Eric // LA Scooter Meetup Group // Stella 4T // Vespa LX // Vespa LXS // Honda Helix // some, uh, projects…
- Halloweenie
- Member
- Posts: 147
- Joined: Mon Nov 03, 2008 7:40 pm
- Location: Drexel Hill, PA
I usually do the same, if I am on E for two rides to school then I need fuel right away. Except last week when I forgot how long I was on empty and barely cruised into a petrol station on fumes.
I will say that the Hot Wing is fantastic fun, but really thirsty.
I will say that the Hot Wing is fantastic fun, but really thirsty.
226 Vintage Hot Wing, GGR Hot Reeds, Mazzy Race Cut Crank, P200 filter, 128 Main, BJ Stack, Trailtech CHT
AAA-O Anything, Anytime, Anywhere, Bar None
AAA-O Anything, Anytime, Anywhere, Bar None
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
- pesce
- Member
- Posts: 106
- Joined: Wed Mar 16, 2011 3:02 am
- Location: Sacramento
No more problems... put another hundred miles on her and no problems... looks as though i get roughly 130 mpg!
have no idea what the issue was, perhaps I didnt have the valve totally in the correct position.
I have noticed though, buying a brand new Stella isnt like buying a brand new car. see my other post topic18023.html
have no idea what the issue was, perhaps I didnt have the valve totally in the correct position.
I have noticed though, buying a brand new Stella isnt like buying a brand new car. see my other post topic18023.html
- pesce
- Member
- Posts: 106
- Joined: Wed Mar 16, 2011 3:02 am
- Location: Sacramento
ok it happened again today. ran out of fuel and started sputtering but I have mastered the quick switch to reserve...
went to the gas station, filled up with .7 gallons of gasoline.
is my math wrong? but that seems like I had a little less than half of a tank left!!
I peered inside the tank and it looked like there was about 2 inches of fuel left.
Oh and great app for android phone users, https://market.android.com/details?id=c ... rch_result
Any ideas?
went to the gas station, filled up with .7 gallons of gasoline.
is my math wrong? but that seems like I had a little less than half of a tank left!!
I peered inside the tank and it looked like there was about 2 inches of fuel left.
Oh and great app for android phone users, https://market.android.com/details?id=c ... rch_result
Any ideas?
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
Reserve is .26 gallons. But if the reserve level is not properly calibrated as it with yours, you'll have to switch over sooner.pesce wrote:ok it happened again today. ran out of fuel and started sputtering but I have mastered the quick switch to reserve...
went to the gas station, filled up with .7 gallons of gasoline.
is my math wrong? but that seems like I had a little less than half of a tank left!!
I peered inside the tank and it looked like there was about 2 inches of fuel left.
Oh and great app for android phone users, https://market.android.com/details?id=c ... rch_result
Any ideas?
- Dooglas
- Moderator
- Posts: 4372
- Joined: Sun Jul 08, 2007 2:17 am
- Location: Oregon City, OR
Are you sure that you are actually filing the tank (or coming anywhere close) when you refuel. If you think you are about empty and the tank only takes 0.7 gallon, it sounds to me like the tank was not previously filled. You may need to hold the fuel nozzle a little higher so that the auto shutoff isn't triggered so soon.
- Lovelandstella
- Member
- Posts: 490
- Joined: Thu Apr 01, 2010 6:19 pm
- Location: Greeley, CO
good point!
This brings up a stupid question I have begging to know...Dooglas wrote:Are you sure that you are actually filing the tank (or coming anywhere close) when you refuel. ...sounds to me like the tank was not previously filled. You may need to hold the fuel nozzle a little higher so that the auto shutoff isn't triggered so soon.
where/what is the max fill line for the Stella 4T?
I *thought* I knew where it was on the Stella 2T (anywhere under the lip of the top). but apparently even if it all fits with the cap off and even with the cap "on" that wont stop the 2t motor from shooting the gas up through the gas cap breather hole like "old faithful"
I do NOT want to make the same mistake with the 4T, expecially since still have the Evap system all hooked up.
- ericalm
- Site Admin
- Posts: 16842
- Joined: Sat Jun 10, 2006 3:01 am
- Location: Los Angeles, CA
- Contact:
I fill mine up to the rim and have never had gas spouting.
Eric // LA Scooter Meetup Group // Stella 4T // Vespa LX // Vespa LXS // Honda Helix // some, uh, projects…
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
- ericalm
- Site Admin
- Posts: 16842
- Joined: Sat Jun 10, 2006 3:01 am
- Location: Los Angeles, CA
- Contact:
That happened to me too—once. Took care of it!desmolicious wrote:I did that, then made the mistake of riding up a steep hill. Gas got into the EVAP system and made the bike run badly for a minute or so.ericalm wrote:I fill mine up to the rim and have never had gas spouting.
Eric // LA Scooter Meetup Group // Stella 4T // Vespa LX // Vespa LXS // Honda Helix // some, uh, projects…
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
Once gas gets in the EVAP system, does it eventually clear by itself or does stuff need to be taken apart/drained?ericalm wrote:That happened to me too—once. Took care of it!desmolicious wrote:I did that, then made the mistake of riding up a steep hill. Gas got into the EVAP system and made the bike run badly for a minute or so.ericalm wrote:I fill mine up to the rim and have never had gas spouting.
Mine seems to have cleared by itself.
I guess I should get a spare gas cap before I do your mod and drill it, cuz if I had a warranty issue this would be seen as tampering..
Hmm, wonder if the PX cap is the same size...
- ericalm
- Site Admin
- Posts: 16842
- Joined: Sat Jun 10, 2006 3:01 am
- Location: Los Angeles, CA
- Contact:
Tampering only applies to affected systems with a warranty issue. Gas cap's pretty cheap, though.
The gas will usually run itself through the system if you let the scoot run with the cap off for a while. You can also pull the hoses pretty easily on the top and let any excess spill out.
The gas will usually run itself through the system if you let the scoot run with the cap off for a while. You can also pull the hoses pretty easily on the top and let any excess spill out.
Eric // LA Scooter Meetup Group // Stella 4T // Vespa LX // Vespa LXS // Honda Helix // some, uh, projects…
- pesce
- Member
- Posts: 106
- Joined: Wed Mar 16, 2011 3:02 am
- Location: Sacramento
Well, it always seems to happen when I am needing to get somewhere and don't have time to check it out.
Again today, sputter sputter stall... (and I was in the reserve position)
I thought, oh crap! now i am really out of gas.
but, I started it up again. it ran poorly like it was going to die for about a minute and then zoom! I was back on the road. There was a gas station about 1 mile away. Filled her up, and yes it was .7 gallons.
WTF
I must have something wrong with my valve or something. is the fuel tank a closed system? Can I open it up and check out whats happening?
Again today, sputter sputter stall... (and I was in the reserve position)
I thought, oh crap! now i am really out of gas.
but, I started it up again. it ran poorly like it was going to die for about a minute and then zoom! I was back on the road. There was a gas station about 1 mile away. Filled her up, and yes it was .7 gallons.
WTF

I must have something wrong with my valve or something. is the fuel tank a closed system? Can I open it up and check out whats happening?
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
It sounds like you may have overfilled it and some gas entered the EVAP system. Once that happens, in essence it becomes a sealed system which eventually causes the stalling after enough gas has been used up from the tank due to a vacuum effect.
Next time it happens, do not fill up. Just open the gas cap and see if it then runs. If it does, then the issue is gas overflow in your evap system. The cure is to unplug it...
Next time it happens, do not fill up. Just open the gas cap and see if it then runs. If it does, then the issue is gas overflow in your evap system. The cure is to unplug it...
- ericalm
- Site Admin
- Posts: 16842
- Joined: Sat Jun 10, 2006 3:01 am
- Location: Los Angeles, CA
- Contact:
I'd preemptively try closing off the evap before it happens again.
Eric // LA Scooter Meetup Group // Stella 4T // Vespa LX // Vespa LXS // Honda Helix // some, uh, projects…
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
I drilled through the gas cap - all the way through - and unplugged the hose from the evap junction to the tank. I then put a little plug into the hose.ericalm wrote:I'd preemptively try closing off the evap before it happens again.
The bike stalled out after a few miles of riding - basically vapour locked. I took the plug out of the hose (still not connected to the evap junction) and then it ran perfectly.
It seems that even though a hole was drilled all the way through the gas cap, there is a membrane inside the cap that still prevents the cap from venting.
I guess I could keep drilling a bigger hole until it finally does vent, but in the mean time if anyone experiences a stalling out, just unplug the hose from the gas tank to the evap. And leave it open.
The worse that happens is that if the tank is 'overfilled', a little gas will dribble out.
- Lovelandstella
- Member
- Posts: 490
- Joined: Thu Apr 01, 2010 6:19 pm
- Location: Greeley, CO
I have had a couple stalls when going uphill for a long time. I will try this.desmolicious wrote:I drilled through the gas cap - all the way through - and unplugged the hose from the evap junction to the tank. I then put a little plug into the hose.ericalm wrote:I'd preemptively try closing off the evap before it happens again.
The bike stalled out after a few miles of riding - basically vapour locked. I took the plug out of the hose (still not connected to the evap junction) and then it ran perfectly.
It seems that even though a hole was drilled all the way through the gas cap, there is a membrane inside the cap that still prevents the cap from venting.
I guess I could keep drilling a bigger hole until it finally does vent, but in the mean time if anyone experiences a stalling out, just unplug the hose from the gas tank to the evap. And leave it open.
The worse that happens is that if the tank is 'overfilled', a little gas will dribble out.
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
Let us know how it works out for you.Lovelandstella wrote:I have had a couple stalls when going uphill for a long time. I will try this.desmolicious wrote:I drilled through the gas cap - all the way through - and unplugged the hose from the evap junction to the tank. I then put a little plug into the hose.ericalm wrote:I'd preemptively try closing off the evap before it happens again.
The bike stalled out after a few miles of riding - basically vapour locked. I took the plug out of the hose (still not connected to the evap junction) and then it ran perfectly.
It seems that even though a hole was drilled all the way through the gas cap, there is a membrane inside the cap that still prevents the cap from venting.
I guess I could keep drilling a bigger hole until it finally does vent, but in the mean time if anyone experiences a stalling out, just unplug the hose from the gas tank to the evap. And leave it open.
The worse that happens is that if the tank is 'overfilled', a little gas will dribble out.
-
- Dealer
- Posts: 12
- Joined: Sun Apr 17, 2011 3:55 am
- Location: Los Angeles
In severe cases, which i have seen one, a tank was filled to full and the evap system sucked up gas continuously till the bike wouldn't run. The owner turned over the bike with electric start till battery died. kick started till fuel was running on ground. Turns out the evap system was pulling fuel into its system nonstop and was dumping it into the air box. There was gas about an inch deep inside the air box. The most important thing to remember is not to overfill the tank. I suggest filling the tank only as high as it sits in chassis. Meaning the one inch it sticks out of the stella frame should be empty and allow for fuel slosh. They do not come with a "Don't Top Off Gas" sticker like some models but this is very important.ericalm wrote:Tampering only applies to affected systems with a warranty issue. Gas cap's pretty cheap, though.
The gas will usually run itself through the system if you let the scoot run with the cap off for a while. You can also pull the hoses pretty easily on the top and let any excess spill out.
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
Thanks for joining this site. I have been very careful not to overfill my tank, but it seems anytime that I climb a steep hill the fuel overflows and plugs the system, causing erratic running and stalling.deadmile wrote:In severe cases, which i have seen one, a tank was filled to full and the evap system sucked up gas continuously till the bike wouldn't run. The owner turned over the bike with electric start till battery died. kick started till fuel was running on ground. Turns out the evap system was pulling fuel into its system nonstop and was dumping it into the air box. There was gas about an inch deep inside the air box. The most important thing to remember is not to overfill the tank. I suggest filling the tank only as high as it sits in chassis. Meaning the one inch it sticks out of the stella frame should be empty and allow for fuel slosh. They do not come with a "Don't Top Off Gas" sticker like some models but this is very important.ericalm wrote:Tampering only applies to affected systems with a warranty issue. Gas cap's pretty cheap, though.
The gas will usually run itself through the system if you let the scoot run with the cap off for a while. You can also pull the hoses pretty easily on the top and let any excess spill out.
To fix this issue, I have just unplugged the hose where it comes out of the tank, and now it runs perfectly. The downside is fuel still spills out of this connector when the tank is near full. I am thinking of running a drain line off it down the side of the cowel, bummer is that this will be a visible hose. But at least it will keep the fuel off the paint.
I know one other persion who simply left the connector open on the EVAP side, and plugged the hose coming from the tank. He then drilled the gas cap for venting to prevent vaccuum lock on the carb.
I tried that, but even though the drill went entirely through the cap (you can see the hole at both ends), the cap remains sealed. It seems there is a membrane inside it that prevents this remedy.
It's a real bummer not to be able to fill the tank fully. To stay emmissions compliant and not stall out it seems that we have to give away a portion of the tank's capacity, even though it is small to start off with. I guess the upside is the great mpg.
-
- Dealer
- Posts: 12
- Joined: Sun Apr 17, 2011 3:55 am
- Location: Los Angeles
One of our mechanics thinks he has a solution to the problem. It would require a "catch can" in the charcoal system. The hose coming from the fuel tank would run down to the catch can and then back up to the roll over valve. Also there would have to be a line that would run from catch can to carb eventually to drain the catch can over time. He thinks a can about the size of a V8 juice can would work but it would require soldering and such. The only other alternative is to disconnect the system and/or run it to the ground...which is not legal.desmolicious wrote:Thanks for joining this site. I have been very careful not to overfill my tank, but it seems anytime that I climb a steep hill the fuel overflows and plugs the system, causing erratic running and stalling.deadmile wrote:In severe cases, which i have seen one, a tank was filled to full and the evap system sucked up gas continuously till the bike wouldn't run. The owner turned over the bike with electric start till battery died. kick started till fuel was running on ground. Turns out the evap system was pulling fuel into its system nonstop and was dumping it into the air box. There was gas about an inch deep inside the air box. The most important thing to remember is not to overfill the tank. I suggest filling the tank only as high as it sits in chassis. Meaning the one inch it sticks out of the stella frame should be empty and allow for fuel slosh. They do not come with a "Don't Top Off Gas" sticker like some models but this is very important.ericalm wrote:Tampering only applies to affected systems with a warranty issue. Gas cap's pretty cheap, though.
The gas will usually run itself through the system if you let the scoot run with the cap off for a while. You can also pull the hoses pretty easily on the top and let any excess spill out.
To fix this issue, I have just unplugged the hose where it comes out of the tank, and now it runs perfectly. The downside is fuel still spills out of this connector when the tank is near full. I am thinking of running a drain line off it down the side of the cowel, bummer is that this will be a visible hose. But at least it will keep the fuel off the paint.
I know one other persion who simply left the connector open on the EVAP side, and plugged the hose coming from the tank. He then drilled the gas cap for venting to prevent vaccuum lock on the carb.
I tried that, but even though the drill went entirely through the cap (you can see the hole at both ends), the cap remains sealed. It seems there is a membrane inside it that prevents this remedy.
It's a real bummer not to be able to fill the tank fully. To stay emmissions compliant and not stall out it seems that we have to give away a portion of the tank's capacity, even though it is small to start off with. I guess the upside is the great mpg.
Upon inspection of the inside cap where the evap fuel hose comes out we have noticed there is no sort of baffle over the evap system line. Therefore when the bike is completely filled up and ran up a hill it will siphon the fuel into evap system and mess with the vacuum causing the motor to suffocate. This is why it is extremely important not to overfill the tank. Also the tank has tons of clearance to the bottom above the motor but it seems the manufacturer failed to utilize the extra space with more fuel capacity. Maybe an aftermarket fuel tank will come out. In my opinion, at 140 prospected mpg you will fill up about as frequent as I do on my Harley Davidson which gets about 150 miles out of a tank of 5 gallons in the city.
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
Hello all,
I joined this site after finding it through googling the issue I am having with my Stella 4t. Seems I am having the vapor lock issue, and the evap system is at fault. I live in a hilly area, and particularly when going up a hill that is bumpy I seem to flood the evap system and then experience power loss once I build up enough vacuum in the gas tank.
After the 3rd time it happened (yesterday on the way to work), I temporarily solved it by disconnecting the evap hose that comes off the tank at its connection to the little black can, bending it over the top of the cap, and taping it down. The bend prevents fuel from spilling out and lets me get home without stalling in front of a texting Hummer driver.
I feel like this issue is one of fundamentally bad/lazy design. There are any number of ways this issue could be avoided, and I will bet that soon some smart cookie will come up with a cheap and easy solution. I am actually going to build myself something this weekend or next, and if it is easy and works well I will share it here.
Question: once fuel has gotten into the system, will it dry itself out eventually or does it need assistance? In other words, do I need to do anything to fix the system before I try a more permanent workaround? The previous two times it happened the issue just went away on its own, but this time I just disconnected the hose without waiting for it to work itself out.
2nd Question: Where is the air intake for the evap system? Seems like air goes into the carb, and also should be allowed to flow into the top of the tank. Where does it come from? Anybody have a schematic? What is the actual mechanism of the problem of vapor lock when it comes from fuel in the evap system?
Re: the fuel tank- isn't that space under it necessary for suspension travel?
Thank you all for your time!
I joined this site after finding it through googling the issue I am having with my Stella 4t. Seems I am having the vapor lock issue, and the evap system is at fault. I live in a hilly area, and particularly when going up a hill that is bumpy I seem to flood the evap system and then experience power loss once I build up enough vacuum in the gas tank.
After the 3rd time it happened (yesterday on the way to work), I temporarily solved it by disconnecting the evap hose that comes off the tank at its connection to the little black can, bending it over the top of the cap, and taping it down. The bend prevents fuel from spilling out and lets me get home without stalling in front of a texting Hummer driver.
I feel like this issue is one of fundamentally bad/lazy design. There are any number of ways this issue could be avoided, and I will bet that soon some smart cookie will come up with a cheap and easy solution. I am actually going to build myself something this weekend or next, and if it is easy and works well I will share it here.
Question: once fuel has gotten into the system, will it dry itself out eventually or does it need assistance? In other words, do I need to do anything to fix the system before I try a more permanent workaround? The previous two times it happened the issue just went away on its own, but this time I just disconnected the hose without waiting for it to work itself out.
2nd Question: Where is the air intake for the evap system? Seems like air goes into the carb, and also should be allowed to flow into the top of the tank. Where does it come from? Anybody have a schematic? What is the actual mechanism of the problem of vapor lock when it comes from fuel in the evap system?
Re: the fuel tank- isn't that space under it necessary for suspension travel?
Thank you all for your time!
- DirtyRAT
- Member
- Posts: 182
- Joined: Sun Apr 17, 2011 11:43 pm
- Location: San Diego, CA
I have been meaning to post this link as a stand-alone item, but this Android app, Gas Buddy, uses the built in GPS function to locate nearest gas stations.pesce wrote:
Oh and great app for android phone users, https://market.android.com/details?id=c ... rch_result
It saved me from a loooong walk on my break-in ride on the Stella last weekend.
Free, too.
https://market.android.com/details?id=g ... rch_result
-
- Dealer
- Posts: 12
- Joined: Sun Apr 17, 2011 3:55 am
- Location: Los Angeles
The little black canister under the seat is a rollover valve. In the event of a crash, this mechanism would fill up with fuel and it would pass down to charcoal canister and then to air intake tube just before the carb and keep fuel from spilling while still venting it. Problem is that it reacts same way with too much fuel in tank or riding up a steep hill with full tank. If fuel has not made it completely through the rollover valve and down to charcoal canister, the valve is still ok and will dry out over time or u can dry it with compressed air. If fuel gets through rollover valve I recommend u change it. I plan to take one of these rollover valves apart to see what is actually happening inside. And to answer the second question which I coincidentally stated in the first...the end of the evap system line is just before the carb on the intake tube. In severe cases the evap system will syphon excess amounts of fuel and it will fill up the air box. I have seen one case and it was due to overfilling the tank and driving up a hill.thatisnotafrog wrote:Hello all,
I joined this site after finding it through googling the issue I am having with my Stella 4t. Seems I am having the vapor lock issue, and the evap system is at fault. I live in a hilly area, and particularly when going up a hill that is bumpy I seem to flood the evap system and then experience power loss once I build up enough vacuum in the gas tank.
After the 3rd time it happened (yesterday on the way to work), I temporarily solved it by disconnecting the evap hose that comes off the tank at its connection to the little black can, bending it over the top of the cap, and taping it down. The bend prevents fuel from spilling out and lets me get home without stalling in front of a texting Hummer driver.
I feel like this issue is one of fundamentally bad/lazy design. There are any number of ways this issue could be avoided, and I will bet that soon some smart cookie will come up with a cheap and easy solution. I am actually going to build myself something this weekend or next, and if it is easy and works well I will share it here.
Question: once fuel has gotten into the system, will it dry itself out eventually or does it need assistance? In other words, do I need to do anything to fix the system before I try a more permanent workaround? The previous two times it happened the issue just went away on its own, but this time I just disconnected the hose without waiting for it to work itself out.
2nd Question: Where is the air intake for the evap system? Seems like air goes into the carb, and also should be allowed to flow into the top of the tank. Where does it come from? Anybody have a schematic? What is the actual mechanism of the problem of vapor lock when it comes from fuel in the evap system?
Re: the fuel tank- isn't that space under it necessary for suspension travel?
Thank you all for your time!
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
cool, thanks for the info!
Is that rollover valve available generically or will I be asking my dealer for one?
So when the evap system plugs up as a result of fuel getting in there and gives us vapor lock, it is the rollover valve that is responsible for the blockage? Or the charcoal filter? Or just fuel in the line? Or something else?
Is that rollover valve available generically or will I be asking my dealer for one?
So when the evap system plugs up as a result of fuel getting in there and gives us vapor lock, it is the rollover valve that is responsible for the blockage? Or the charcoal filter? Or just fuel in the line? Or something else?
-
- Dealer
- Posts: 12
- Joined: Sun Apr 17, 2011 3:55 am
- Location: Los Angeles
- am guessing you will have to buy the rollover valve from dealer but do a search on google just in case. Vapor lock is cause by fuel getting into rollover valve. This system acts as a vent for fuel system so when fuel is in the system it can't breathe correctly. In more serious cases the fuel getting by rollover valve and down to charcoal canister will really choke motor, if it will even run. The large charcoal canister can be dried out with compressed air. We change the fuel soaked lines and rollover valve in extreme cases.thatisnotafrog wrote:cool, thanks for the info!
Is that rollover valve available generically or will I be asking my dealer for one?
So when the evap system plugs up as a result of fuel getting in there and gives us vapor lock, it is the rollover valve that is responsible for the blockage? Or the charcoal filter? Or just fuel in the line? Or something else?
- DirtyRAT
- Member
- Posts: 182
- Joined: Sun Apr 17, 2011 11:43 pm
- Location: San Diego, CA
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
-
- Dealer
- Posts: 12
- Joined: Sun Apr 17, 2011 3:55 am
- Location: Los Angeles
We have been guestimating that you shouldn't fill the tank past the line where it extends from the chassis...meaning the one inch or so that it sticks up about the painted part of the stella should be empty and allow for fuel slosh and be room for when driving up steep hills. This is just our recommendation. You can fill it more but you run the risk of getting fuel in evap system.DirtyRAT wrote:How does a person determine how much to fill the Stella gas tank so that it's 'full', but not too full to cause evap system flooding like this thread discusses?
I'm a new Stella owner, and would love to know...
Thanks
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
I have just taped down the hose as you have, and hopefully this will stop gas spilling out!thatisnotafrog wrote: After the 3rd time it happened (yesterday on the way to work), I temporarily solved it by disconnecting the evap hose that comes off the tank at its connection to the little black can, bending it over the top of the cap, and taping it down. The bend prevents fuel from spilling out and lets me get home without stalling in front of a texting Hummer driver.
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
If they are interchangeable then I'll get one. I'd hate to order one and find out they are not...thatisnotafrog wrote:Cool, let us know if it works for you as a temporary solution!
I heard today that the 2T Stella gas caps are vented and are interchangeable with the 4T. Perhaps I will get me one of those and see if that (along with being careful not to overfill the thank) solves my issue.
The gas cap on my PX is smaller than the Stella.
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
Well this is interesting- so I got my Stella back from its 500 mile service today, and I had told the guys about my evap problems. They poked around and said upon testing, they found the valve mounted under the seat was installed backwards. They said the arrows were right, but the valve itself was flipped. So they took it out, flipped it, put it back in. Interesting. So far so good, but I'm not topped off. Lots more power now, especially on the high end, but that could easily be the valve adjustment and whatever else they did. But if what they say is true about the valve, then I constantly had some vacuum in the tank, the more gas I had the worse it would have been- which is how it felt.
Gonna fill up and drive up some hills at full throttle and see how it feels. Back in a few.
BTW I have not gotten my new cap in the mail, so this is with everything still stock, just with the valve flipped.
Gonna fill up and drive up some hills at full throttle and see how it feels. Back in a few.
BTW I have not gotten my new cap in the mail, so this is with everything still stock, just with the valve flipped.
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
Ok, just got back, strangest result possible: no difference.
Same type of problem: throttle high, hilly, bogs down then dies. Wait a minute and it starts again, repeat process. Unplug hose, problem solved.
So either they didn't do anything to the valve, or the problem lies elsewhere.
Either way, I'm done with this evap system. If the vented cap works, I'll just plug up the hose and call it a day. Can't wait for it to arrive.
Here is my temporary solution:

Uploaded with ImageShack.us
Same type of problem: throttle high, hilly, bogs down then dies. Wait a minute and it starts again, repeat process. Unplug hose, problem solved.
So either they didn't do anything to the valve, or the problem lies elsewhere.
Either way, I'm done with this evap system. If the vented cap works, I'll just plug up the hose and call it a day. Can't wait for it to arrive.
Here is my temporary solution:

Uploaded with ImageShack.us
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
-
- Member
- Posts: 28
- Joined: Tue Apr 19, 2011 5:41 pm
- Location: NC
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
Bummer, but thanks for the follow up.thatisnotafrog wrote:NO! Grrrr. Gonna have to call and see what happened to it- it was coming from Genuine.
In the mean time, your hose trick is working but like you I would prefer a cleaner solution.
edit: I called Scooterwest and they have the vented 2T caps in stock. They checked and it fits on the 4T. They are shipping me one.
- rondothemidget
- Member
- Posts: 245
- Joined: Wed Jul 02, 2008 2:36 pm
- Location: Orange County
I've got about 50 miles on my 4T and it stalled about 5 times on the 10 mile ride home today. Different than everyone else, it seems, is that it was happening on flat ground. The tank is filled to about an inch below the top. First time, it started right up after switching to reserve so I thought that solved the problem. Then it did it a few more times while on reserve. It would either bog down when I opened the throttle, then die when I pulled to a stop or just stall when I idled at a stop. Interestingly, it was fine when I went up the one steep hill on my ride.
I'll be experimenting with the duct-taped evap hose tomorrow.
I'll be experimenting with the duct-taped evap hose tomorrow.
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
-
- Member
- Posts: 2
- Joined: Wed May 18, 2011 11:54 am
- Location: United States
Stella 4T Stall
My dad just bought a stella 4T and his was stalling out on flat land. So I disconnected the hose to the evap and so far so good. One thing I did note was the fact if I tried to blow air into the evap system I could not. So as he would ride it would create a vacuum in the tank and starve the scoot of fuel.
- desmolicious
- Member
- Posts: 651
- Joined: Tue Mar 29, 2011 8:38 pm
- Location: Venice Beach
Re: Stella 4T Stall
Plug that hose otherwise gas will leak out of it and dribble down the side of the bike. But only do that after you replace the gas cap with that from a Stella 2T. That one is vented.karlmarsh wrote:My dad just bought a stella 4T and his was stalling out on flat land. So I disconnected the hose to the evap and so far so good. One thing I did note was the fact if I tried to blow air into the evap system I could not. So as he would ride it would create a vacuum in the tank and starve the scoot of fuel.
That's what I have done and no issues anymore.