Scooter is sputtering and it's getting worse

smillerlou · Post by **smillerlou** » Thu Jul 24, 2014 2:48 pm

About a month ago I noticed that my scooter (2012 4Stroke Stella) would start sputtering as I was riding. It was mainly when I first started riding and then after it warmed up it seemed to get better. I took it in to Scooter Works in Chicago and they said it I might need to have the carburetor cleaned out. So I had them do that and after waiting a week I picked it up. As soon as I pulled out I noticed the problem had not been fixed and it was exactly the same. I didn't feel like going back because every time I bring it there it is at least a week or 2 to fix and they never call me to let me know what is going on until I call them.

So anyways I've had it for about a week now and it's getting worse. It keeps stalling on my while I'm riding. Today I heard a few small pops like it was back firing while I was riding. Also, its kind of like I have to be giving it gas all the time or it will die. Even in 4th gear if I'm not revving it then it starts to sputtering.

I'm not real handy with my scooter but I'd like to try and fix this myself. Is it possible I just need a new spark plug?

I've taken my scooter in like 5-6 times in about a year and a few months. I loved my stella at first but now i'm starting to have buyers remorse.

misterbrackets · Post by **misterbrackets** » Thu Jul 24, 2014 5:55 pm

My guess would be that the idle/pilot jet is clogged. But they said they cleaned your carb. I had a similar problem when I first got mine and it turned out to be a clogged idle jet. (It's easy to check this out yourself)

I'm sure there are others who will chime in with other things to check, but this is the experience I had with mine.

How does it run when you are accelerating? Or just cruising down the road at a steady 3/4 throttle? Is there a difference when warmed up? What happens if you ride with the choke 1/2 way out?

That's lame if they just cleaned the carb without investigating the problem further. I've had good mail-order experiences with them in the past, though.

Neurotic-Hapi-Snak · Post by **Neurotic-Hapi-Snak** » Thu Jul 24, 2014 7:22 pm

misterbrackets wrote:My guess would be that the idle/pilot jet is clogged. But they said they cleaned your carb. I had a similar problem when I first got mine and it turned out to be a clogged idle jet. (It's easy to check this out yourself)

The problem with idle jets is they are so small that cleaning them often doesn't unclog them, and you can't get a wire to fit through. You can try letting the idle jet soak in carb cleaner overnight, but best bet is to buy a new one. Keihin part# N424-74C size# 40.

misterbrackets · Post by **misterbrackets** » Thu Jul 24, 2014 9:03 pm

Yeah - they are small and get clogged easily. I used carb cleaner and a sewing needle to clean it out. But it clogged a few times. I haven't had this problem since getting new jets. Funny thing is the #40 Keihin jet I bought was clearly larger than the stock #40 that came with the carb. I could visually tell the difference when holding them up to a light and looking through. There were also two extra holes on the side of the new one.

Maybe there is junk getting into the carb, and after it was cleaned, reintroduced itself. I think eventually it will work its way out, maybe through a couple more cleanings. I've also had decent luck adding techron to the gas, though I haven't felt the need to do that recently.

Ofcourse, it may not be the carb at all, but checking out the jets for yourself is the easiest place to start. This video shows you how : http://vimeo.com/20618680

srbbnd · Post by **srbbnd** » Fri Jul 25, 2014 12:11 am

topic26577.html

^You might check this youtube video in this thread. I was having some problems with my needle clip plate. Was an easy fix and has made a huge difference.

smillerlou · Post by **smillerlou** » Fri Jul 25, 2014 2:51 pm

thanks guys I'm going to see what I can do this weekend. I just wish I knew what I was doing

misterbrackets · Post by **misterbrackets** » Fri Jul 25, 2014 5:38 pm

smillerlou wrote:thanks guys I'm going to see what I can do this weekend. I just wish I knew what I was doing

The more you do, the more you'll know what you're doing

This is a good first scooter DIY task. Just check out the videos posted above first.

Be SURE to turn the fuel lever under the seat OFF and run the engine until it dies - or you'll spill a little bit of gas taking off the carb.

(The drain screw on the bottom of the carb lets the remaining gas flow out from one of the little rubber hoses connected to it, but you don't need to do this if you just let the carb run dry after first turning off the fuel lever)

All you really need as far as tools is a set of allen wrenches and a screwdriver with some different bits (flat/phillips). Then get some carb cleaner (that comes with a tiny red straw ala WD-40 to blow it through the jets) and a couple small sewing needles to clean any debris from the jets.

smillerlou · Post by **smillerlou** » Fri Jul 25, 2014 5:59 pm

Ok I think I can handle this:) So basically I'm looking to see if that washer looking part moved to another notch on the needle?

mister brackets: it seems to be ok when I'm accelerating (not all the time), but during 3/4 throttle that's when it has the most problems. It also seemed to be better once it was warmed up but it has been getting worse over time and now I'm afraid to ride it because it has been stalling out completely. I haven't tried the choke 1/2 way out yet. Also, when it is idling it sometimes stalls unless I'm using the throttle.

Yes they are very friendly at scooterworks chicago and have given me some price breaks because of my issues, but I guess I wasn't expecting to have to bring it in so much. I wish I could take a class on how to do my own maintenance.

srbbnd · Post by **srbbnd** » Fri Jul 25, 2014 9:22 pm

I would first check to make sure it is screwed on tight enough. If it is then open it up and make sure everything is in the correct position. There probably wont be any notches and will just have one notch where it should be located.

misterbrackets · Post by **misterbrackets** » Fri Jul 25, 2014 10:38 pm

If there are notches, I think the factory setting is the middle notch (mine has 5 notches if I remember correctly). Use a small pliers to grab the ring/clip if you need to pull it off.

viney266 · Post by **viney266** » Sat Jul 26, 2014 12:16 am

The early bikes were adjustable, but the gubment put a stop to that. If you have the adjustable needle its a big help, if not you could shim it with a very small washer.

Neurotic-Hapi-Snak · Post by **Neurotic-Hapi-Snak** » Sat Jul 26, 2014 2:47 am

viney266 wrote:The early bikes were adjustable, but the gubment put a stop to that. If you have the adjustable needle its a big help, if not you could shim it with a very small washer.

Only the EPA would think making a carb non-adjustable made sense.

smillerlou · Post by **smillerlou** » Sun Jul 27, 2014 5:45 pm

ok so I'm pretty frustrated. So I first started unscrewing something that was right above on the cable where I should have been unscrewing. Realizing that I wasn't sure what I was doing I screwed it back to the position it was at. I watched the video and found the cap looking thing that I needed to unscrew to get to the carburetor needle. The cap was tight. I pulled it out and the spring kind of sprung out real quick. I didn't hear anything drop so I'm hoping I didn't lose any pieces. I pulled the needle out and the little washer was still in the notch. The thing that was different about the video is that I didn't have the bigger washer that the guy puts on at the end of the video that has to be facing the same direction as the slot. I have like a V shaped spring that I'm guessing does the same thing? Or maybe when the spring went off the washer went shooting way far away.

Anyways, it won't start at all anymore after putting everything back together and I'm kind of at a loss of what to do now. I guess take it back to scooterworks some how and tell them I messed it up even more. I'm about to lose it right now! Dang it!

Neurotic-Hapi-Snak · Post by **Neurotic-Hapi-Snak** » Sun Jul 27, 2014 11:55 pm

There shouldn't be any washer, at least on mine there wasn't.

srbbnd · Post by **srbbnd** » Mon Jul 28, 2014 1:55 am

There is no washer, I think what you are talking about is the little V-thing. In the video the washer thing is the V-thing on the Stella. The scooter should still start, is there a lot of play on the throttle cable?

djp4059 · Post by **djp4059** » Mon Jul 28, 2014 3:56 am

You may have put it back in wrong, take it back out and turn it 180 degrees and slide it back in. I did that once before. If you put it in backwards the throttle valve and needle don't go all the way down. Carbs are very easy to work on. Your sputtering problem is most likely caused by the pilot jet (idle jet) being obstructed or in need of adjustment. I bought my Stella from Scooterworks also, but I live in the southwest suburbs and its a pain driving all the way up to their location on the north side, to much traffic up there.

smillerlou · Post by **smillerlou** » Tue Jul 29, 2014 6:19 pm

Ok, so let me show you with a video on what's going on.

https://vimeo.com/102048394

1. I think I messed something up originally when I started to unscrew the cable adjuster. I'm not even sure what it does because even when its as tight as it goes the cable moves freely as you can see at 2:00.

2. at the very end you can see my hit the throttle and it doesn't seem like there is any tension on it at all.

3. I was looking at the parts diagram again and I don't remember seeing a Gasket (part#4) when the spring fell out. I haven't double check but i'm hoping it didin't fall out too.

Is there any hope for me??

djp4059 · Post by **djp4059** » Tue Jul 29, 2014 8:04 pm

From the video I can't tell if you put the throttle valve in correctly, I think that long groove on the side of the throttle valve passes threw a guide on the inside of the carb and has to go all the way down. If its not all the way down your throttle will act like its wide open, hence the lack of tension on your throttle. Or it could be from what you said about tightening the throttle cable nuts on top of the carb, you may have adjusted that to wide open. One way to find out is to leave the top attached to the carb and take the rubber intake hose from the air filter off and look inside the carb and see if the throttle valve is all the way down. It should cover the port almost completely except for a little at the bottom. When you pull on your throttle it lifts the throttle valve up which lifts the needle up and allows more gas to be sucked threw the main jet. If its not all the way down I would first adjust the cable and start loosening it up and see if the throttle valve starts closing (going down) if it doesn't go down then you'll have to take it out and put it back in correctly and then readjust the cable.

PM me, if your close by or if you can get it to Palos Hills I can help you.

smillerlou · Post by **smillerlou** » Tue Jul 29, 2014 9:03 pm

I checked it out again and it looks like I put the throttle valve in the wrong way. I turned it 180 degrees and tightened it down. The throttle cable seems a lot more secure and definitely has the tension back. I figured since it can only go in 2 ways it has to be the right way. I was able to start it once, but that was it.

Where exactly is the Idle Jet?

djp4059 · Post by **djp4059** » Tue Jul 29, 2014 9:28 pm

To get at the idle jet itself you would have to take off the bottom of the carb. Inside you will see two small brass fittings that look like nuts with a hole in the middle, the one in the center that the needle goes threw is the main the other one is the idle.

The adjustment for the idle jet is to the right of the the brass screw on the side of the carb. It doesn't look like a screwhead. But you can adjust it with a pair of needle nose pliers( took mine all the way out and sliced a slot for a screw driver with a dremel). You need to turn it all the way in until it lightly seats and then turn it out 1 and a 1/2 turns, thats their base line. If you have a tach you can adjust it till you get the highest rpms .

Here's a pretty good video explaining how carbs work and how to adjust them - https://www.youtube.com/watch?v=y836ZPjvoMI

smillerlou · Post by **smillerlou** » Fri Aug 22, 2014 3:59 pm

So I ended up taking the my stella to another motorcycle mechanic and it has never run this good ever. He said the carburetor and air filter were super dirty. The spark plug was also a mess. I'm so confused how scooterworks chicago can take 2 weeks to "clean" the carburetor and then obviously not do anything. I'm not even sure if they even looked at my scooter.

But in the mean time I ended up buying a motorcycle:) If anyone in Chicago wants to buy a 2012 Stella hit me up!

jimmbomb · Post by **jimmbomb** » Sat Aug 23, 2014 2:16 am

Is it RED ???

lovemysan · Post by **lovemysan** » Sun Aug 24, 2014 1:48 pm

misterbrackets wrote:
smillerlou wrote:thanks guys I'm going to see what I can do this weekend. I just wish I knew what I was doing
The more you do, the more you'll know what you're doing This is a good first scooter DIY task. Just check out the videos posted above first.

Be SURE to turn the fuel lever under the seat OFF and run the engine until it dies - or you'll spill a little bit of gas taking off the carb.

(The drain screw on the bottom of the carb lets the remaining gas flow out from one of the little rubber hoses connected to it, but you don't need to do this if you just let the carb run dry after first turning off the fuel lever)

All you really need as far as tools is a set of allen wrenches and a screwdriver with some different bits (flat/phillips). Then get some carb cleaner (that comes with a tiny red straw ala WD-40 to blow it through the jets) and a couple small sewing needles to clean any debris from the jets.

Wd40 is lousy carb cleaner. Berrymans b12 chemtool is the cleaner of choice. be sure and wear gloves and eye protection. After 20 years of use I took a shot to the eye last month.

Modern Buddy

Scooter is sputtering and it's getting worse

Scooter is sputtering and it's getting worse

Sputtering