Why Carburetors?

skipper20 · Post by **skipper20** » Fri Sep 29, 2017 3:16 pm

I can't help but noticing that most of the help requests on this forum involve carburetor problems. And, some of them are really aggravating. The problems go on and on. Why are scooter makers still using carburetors on many of their models when car and truck makers abandoned them years ago in favor of fuel injection? Something to think about if one is planning on a new scooter purchase.

Bill in Seattle
'12 Buddy 170i Oxford Green
'14 Hooligan 170i Matte Green

GregsBuddy · Post by **GregsBuddy** » Fri Sep 29, 2017 5:16 pm

Cost and lack of regulations forcing cleaner emissions.
As sophisticated as carb's have become, they're still poor at delivering the right volume of fuel at the right time and conditioned for high combustion efficiency.

babblefish · Post by **babblefish** » Fri Sep 29, 2017 7:36 pm

Carburetors have been around since the beginning of the internal combustion engine and have been, for the most part, very reliable. I put 250K miles on a Jeep that was carburetted. My '66 Mustang has a little over 200K on a carburetor. Both of my scooters are running fine on their carburetors. That being said, I'm not a luddite and believe that FI is a better fuel management system when properly implemented. Carburetors, on the other hand, are easier for the DIYer to tweak and fine tune.

Tazio · Post by **Tazio** » Fri Sep 29, 2017 9:07 pm

I have a carburetor on my Buddy and two on my Ural. Never touched the carb on the Buddy in over ten years. Only thing I've done on the Ural is balance them so they both work the same. Zero problems. I think most people that have problems screw them up fiddling with them or trying to fix a problem caused by something else.

Also have had carbs on may cars including some built in the 1920's for many decades with no problems.

wheelbender6 · Post by **wheelbender6** » Sat Sep 30, 2017 2:05 pm

Hot rodders like the adjustability of the carb.if you make engine mods, you can adjust the fuel/air ratio with a main jet change. Jets are cheap.
-a lot of EFI scoots cannot be kick started with a dead battery. You must charge the battery before the engine will run. I have kick started my carbureted Buddy many times with a weak battery.

babblefish · Post by **babblefish** » Sun Oct 01, 2017 4:25 am

wheelbender6 wrote:Hot rodders like the adjustability of the carb.if you make engine mods, you can adjust the fuel/air ratio with a main jet change. Jets are cheap.
-a lot of EFI scoots cannot be kick started with a dead battery. You must charge the battery before the engine will run. I have kick started my carbureted Buddy many times with a weak battery.

Just to add to that, ever try to bump start an FI car or motorcycle with a dead battery? No bueno.

babblefish · Post by **babblefish** » Sun Oct 01, 2017 4:28 am

Tazio wrote:I have a carburetor on my Buddy and two on my Ural. Never touched the carb on the Buddy in over ten years. Only thing I've done on the Ural is balance them so they both work the same. Zero problems. I think most people that have problems screw them up fiddling with them or trying to fix a problem caused by something else.

Also have had carbs on may cars including some built in the 1920's for many decades with no problems.

Oh you lucky bum, I've always wanted a Ural, but have nowhere to park it. Always thought it would be great to pack it up with camping and fishing gear and go somewhere.

Dooglas · Post by **Dooglas** » Sun Oct 01, 2017 4:38 am

Tazio wrote:I have a carburetor on my Buddy and two on my Ural. Never touched the carb on the Buddy in over ten years.

My experience with our Buddy 125 has been the same. Ten years and have never touched the carb.

wheelbender6 · Post by **wheelbender6** » Sun Oct 01, 2017 1:30 pm

When your scoot has a carb, you must ride it regularly or add a fuel stabilizer. Otherwise, jets and other small orifices in the carb become clogged with congealed fuel. Makes it run like crap.
-With EFI , fuel is delivered under high pressure, so it does not clog as easily.

babblefish · Post by **babblefish** » Sun Oct 01, 2017 4:50 pm

wheelbender6 wrote:When your scoot has a carb, you must ride it regularly or add a fuel stabilizer. Otherwise, jets and other small orifices in the carb become clogged with congealed fuel. Makes it run like crap.
-With EFI , fuel is delivered under high pressure, so it does not clog as easily.

I'm not trying to be a d*ick here, but I've left my scooter for several months without riding and the engine started up with no issues. I've done the same with a couple of cars, too. The bigger issue in my mind is with todays gasoline which has alcohol in it. The alcohol attracts and allows water to mix with the fuel, which can then precipitate out and settle on the bottom of the fuel tank and float bowl when the vehicle is not used for a long time. This can cause corrosion and rot out the bottom of fuel tanks. I had a '71 VW Beetle develop a pin hole leak on the bottom of it's fuel tank due to this. Had to remove the tank, flush it out thoroughly with water, then braze a patch over the hole to seal the leak.
Interestingly, gasoline from five decades or so ago (before alcohol was added) that was left sitting in fuel tanks did not rot out the metal and have even been known to still run an engine.

wheelbender6 · Post by **wheelbender6** » Sun Oct 01, 2017 5:12 pm

I agree that modern fuel blends contribute a lot to the carb problems. In the early 70s, we could crank up our bikes after months of sitting and they ran fine.

babblefish · Post by **babblefish** » Sun Oct 01, 2017 5:42 pm

wheelbender6 wrote:I agree that modern fuel blends contribute a lot to the carb problems. In the early 70s, we could crank up our bikes after months of sitting and they ran fine.

I didn't mean to contradict your statement that fuel can cause problems when left to sit too long because it is possible for this happen depending upon conditions and the quality of fuel used. There are several formulations of gasoline which can differ from region to region. I'm guessing (hoping?) that California has good gas because my Buddy sat for a year and a half before I bought it without being ridden and while the fuel turned dark and smelled like turpentine, the carburetor float bowl was relatively clean and the bottom of the fuel tank was perfectly clean. I didn't try to start the engine with that fuel though...

PhillyKick · Post by **PhillyKick** » Tue Oct 03, 2017 2:57 am

babblefish wrote:
wheelbender6 wrote:Hot rodders like the adjustability of the carb.if you make engine mods, you can adjust the fuel/air ratio with a main jet change. Jets are cheap.
-a lot of EFI scoots cannot be kick started with a dead battery. You must charge the battery before the engine will run. I have kick started my carbureted Buddy many times with a weak battery.
Just to add to that, ever try to bump start an FI car or motorcycle with a dead battery? No bueno.

I bump started my passat with literally no battery at all for three days once. Not an issue.

Not sure why everyone thinks you couldn't possibly attach a kickstart to an FI scooter, especially since the battery probably wouldn't be totally dead if you needed to use it, just a bit weak. Heck, if you could lock the belt and clutch, you could put it in run and roll start the thing.

babblefish · Post by **babblefish** » Tue Oct 03, 2017 6:46 am

PhillyKick wrote:
babblefish wrote:
wheelbender6 wrote:Hot rodders like the adjustability of the carb.if you make engine mods, you can adjust the fuel/air ratio with a main jet change. Jets are cheap.
-a lot of EFI scoots cannot be kick started with a dead battery. You must charge the battery before the engine will run. I have kick started my carbureted Buddy many times with a weak battery.
Just to add to that, ever try to bump start an FI car or motorcycle with a dead battery? No bueno.
I bump started my passat with literally no battery at all for three days once. Not an issue.

Not sure why everyone thinks you couldn't possibly attach a kickstart to an FI scooter, especially since the battery probably wouldn't be totally dead if you needed to use it, just a bit weak. Heck, if you could lock the belt and clutch, you could put it in run and roll start the thing.

My guess is that a car has enough fuel line area to hold enough fuel pressure to allow a bump start, but I'm not so sure a small scooter engine system would, but I guess it's possible. I do know that with my Blur, when the battery is too low to crank over the engine, the electronics in my dash goes blank and the clock resets to some random time. Not sure what the low voltage cut-off point is with a scooter's ECU. I do know that the fuel pump wouldn't work.

wheelbender6 · Post by **wheelbender6** » Tue Oct 03, 2017 11:25 am

Many EFI scoots, like the buddy 170i, have no kick starter.

charlie55 · Post by **charlie55** » Tue Oct 03, 2017 2:27 pm

Why carburetors?

Long-time members all know that there's one universal answer to questions like this:

"Why red is red!"

BuddyRaton · Post by **BuddyRaton** » Wed Oct 04, 2017 3:40 pm

charlie55 wrote:Why carburetors?

Long-time members all know that there's one universal answer to questions like this:

"Why red is red!"

NICE!

DeeDee · Post by **DeeDee** » Wed Oct 04, 2017 4:07 pm

I've owned both the 170i and a couple of 125s. I think the 125 is a better scooter. If the 125 dies, won't start or just plain starts acting funny, a guy with average mechanical skills and no diagnostic equipment has a real good chance of getting it sorted. Simply not the case with a fuel injected scooter. At least on the scooters I have owned, the carbed bike was smoother. Top speed and acceleration differences were really negligible.

Cheaper to buy and maintain, kick starter and bullet proof, time tested design built with modern materials. That's why.

jrsjr · Post by **jrsjr** » Thu Oct 05, 2017 5:31 am

Thanks for the reminder to put Seafoam in my latest gas fillup!

Aloha Joe · Post by **Aloha Joe** » Sun Nov 26, 2017 5:39 am

Fuel injected engines require an ECU, which in turns requires software/programming, more sensors, etc. So it's more complicated and expensive to make.

BuddyRaton · Post by **BuddyRaton** » Sun Nov 26, 2017 3:35 pm

GregsBuddy wrote:Cost and lack of regulations forcing cleaner emissions.
As sophisticated as carb's have become, they're still poor at delivering the right volume of fuel at the right time and conditioned for high combustion efficiency.

Not sure of the data to back up this claim, I haven't seen any showing that a carb delivers poor volume at the right time. I really haven't seen major differences in MPG between EFI and carb Buddies. That is going to depend more on riding style than anything else.

Ootscoot · Post by **Ootscoot** » Thu Nov 30, 2017 2:36 am

Here at our shop we like carbs - keep us busy. Most of the issues are with bikes that have not been used in several months, filled with CA fuel with high ethanol. It actually turns the inside of the carb green.
Vespa and Genuine Buddy seem to have less of an issue with this than Kymco, Sym or Lance scoots.
We do like the performance of carbureted bikes - especially when tuned.
I did purchase 5 Sym Citycom 300i that had been stored in a warehouse for over a year - with gas in them - had to replace 2 injectors and 4 fuel pumps.

viney266 · Post by **viney266** » Thu Nov 30, 2017 11:14 pm

Yes, Carbs work just fine. Now, if we could get the E10 OUT of the fuel..then we wouldn't have so many problems.

babblefish · Post by **babblefish** » Fri Dec 01, 2017 6:43 am

viney266 wrote:Yes, Carbs work just fine. Now, if we could get the E10 OUT of the fuel..then we wouldn't have so many problems.

This is possible. There are manufacturers out there selling kits to extract the ethanol out of gasoline or you can follow these instructions:

<iframe width="560" height="315" src="https://www.youtube.com/embed/kSnE4MYwRzs" frameborder="0" allowfullscreen></iframe>

exmayor · Post by **exmayor** » Fri Dec 01, 2017 12:15 pm

I only run ethanol free gas with 1 ounce of Seafoam per gallon. For most of my riding I fill up at home from a fuel can. I hav this app https://www.pure-gas.org which uses your location.
I know that I am paying about $.60 per gallon more but my Buddy runs really well and I donâ€™t have the issues from E10.

exmayor · Post by **exmayor** » Fri Dec 01, 2017 12:17 pm

I only run ethanol free gas with 1 ounce of Seafoam per gallon. For most of my riding I fill up at home from a fuel can. I hav this app https://www.pure-gas.org which uses your location.
I know that I am paying about $.60 per gallon more but my Buddy runs really well and I donâ€™t have the issues from E10.