Modern Buddy

I was able to get the 2007 Buddy 125 I bought off Craig's list running pretty solid yesterday after reinstalling the carb that I cleaned and make some minor adjustments to the fuel/air adjustment screw.

I let it warm up for a few minutes then decided to take it on its maiden voyage. It seems to accelerate ok but topped out at about 30bmph.

Now I'm a big guy at 6'3 275, however I've driven the Buddy 125s at the dealership and was able to get them up to 45-50 no problem and that was with a little throttle to spare.

From what I can tell, everything is stock. The air filter looks almost brand new to me with only 730 miles on this scooter. I also drained all the fuel and put in fresh 89 octane with a little bit if Sea Foam. The only thing I didn't do was replace the fuel filter.

Any tips on what might be causing the slow top speed?

Thanks!

I'd suspect that your vaccuum diaphragm isn't seated properly in the carburetor. See the following thread for a fix:

topic27908.html

Or the main jet is partially clogged. I'd say it is time for a carb cleaning or rebuild.

I actually didn't touch that part of the carb. Any chance it got knocked loose when it was upside down or moving around?

Dooglas wrote:Or the main jet is partially clogged. I'd say it is time for a carb cleaning or rebuild.

Just finished cleaning the carb. Definitely nothing clogged there.

bigmike7801 wrote:I actually didn't touch that part of the carb. Any chance it got knocked loose when it was upside down or moving around?

Hi Big Mike, Are you saying you didn't touch the diaphragm? Did you take out the two screws, and remove the black cap?

If you left the diaphragm in place, there is a chance of crud build up on the slides that is not letting it move freely.

If you did not remove it, you should gently take the slide out and be sure it, and the grooves it mates with are spotless. Then put it back together slowly add a small bit of grease around the lip as you fit it back. Fit the black cap, then slowly remove it. Inspect to be sure the lip looks fully seated. It may take a time or two to get the lip seated properly. The carb relies on vacuum to raise the diaphragm, thus increasing your speed. If the slide is sticking, or a you have slight vacuum leak your acceleration will be compromised.
Good thing is you can do this through the seat bucket without removing the carb.

DeeDee wrote:

bigmike7801 wrote:I actually didn't touch that part of the carb. Any chance it got knocked loose when it was upside down or moving around?

Hi Big Mike, Are you saying you didn't touch the diaphragm? Did you take out the two screws, and remove the black cap?

If you left the diaphragm in place, there is a chance of crud build up on the slides that is not letting it move freely.

If you did not remove it, you should gently take the slide out and be sure it, and the grooves it mates with are spotless. Then put it back together slowly add a small bit of grease around the lip as you fit it back. Fit the black cap, then slowly remove it. Inspect to be sure the lip looks fully seated. It may take a time or two to get the lip seated properly. The carb relies on vacuum to raise the diaphragm, thus increasing your speed. If the slide is sticking, or a you have slight vacuum leak your acceleration will be compromised.
Good thing is you can do this through the seat bucket without removing the carb.

Correct, that's what I'm saying. I'll give this a shot.

Do I need to drain or remove the carb before doing this?

Thanks.

Be sure you check air pressure as well. Those tires will look fine with 15lbs of air in them. Every pound of pressure counts on such small wheels.

DeeDee wrote:Be sure you check air pressure as well. Those tires will look fine with 15lbs of air in them. Every pound of pressure counts on such small wheels.

I had the front at 22.5 and the rear at 25.

I go 31 rear and 29 front.

Well I was able to get the diaphragm seated into the lip and all put together but it doesn't seem to have done the trick.

I have to have the idle screw screwed down all the way in order for the scoot to idle and after a minute or two after a cold start it idles pretty roughly.

Also the scoot dies pretty soon after I release the throttle.

Sounds like an air leak. Spray carb cleaner or starting fluid around the carb/intake area and listen for changes in RPM. There shouldn't be any.

I am having th same low speed issue. I found a black rubber tube hanging down by my transmission while I was in there thinking that was my issue. But my motor sounds great and I have clear smoke coming out of my muffler still can't figure it out.

I am having this same issue with a 2007 Buddy 125 that sat for 4 years with gas in the tank. Scooter has 3000 miles.
I have cleaned the carb and then rechecked everything a second time to confirm the diaphragm was seated and the jets still weren't clogged.
Air filter looks good but I have ordered a new one anyway.
Fuel filter looks good and seems to flow well.
Flushed the fuel tank 3 times and added fuel treatment (although not the magical Sea Foam).
Sprayed carb cleaner around all intake areas with no change in RPM.
Adjusted rear brake to ensure it wasn't dragging.
Replaced the spark plug.
Tires are at 31 psi.
The Buddy is idling great and runs great but tops out at about 20 bmph. It doesn't die or cut out it just feels like that's all there is. I'm a small guy (130 lbs).
Any other suggestions?

That diaphragm is a tricky beast. You really can't tell by looking at it if it is seated correctly. I use a thin film of plumbers grease on my index finger. I work my way around the lip of the carb to transfer a thin film to it. Then, carefully work the diaphragm on. It might take you a few tries to get it right. The problem you are describing sounds just like a bad diaphragm seal.
Did you remove the intake manifold to get the carb off? Check your connection there as well.

DeeDee wrote:That diaphragm is a tricky beast. You really can't tell by looking at it if it is seated correctly. I use a thin film of plumbers grease on my index finger. I work my way around the lip of the carb to transfer a thin film to it. Then, carefully work the diaphragm on. It might take you a few tries to get it right. The problem you are describing sounds just like a bad diaphragm seal.

Funny, I did the same thing with the plumbers grease! I suspect you are correct that the diaphragm is still the problem. I just really didn't want to pull the carb a 3rd time

You don't have to pull the carb to work on the diaphragm, if that is what you are saying. Pull the seat bucket and boom there it is. Check your manifold connections while you are at it.

I have checked and rechecked the diaphragm and am positive it is positioned correctly. I definitely have a leak somewhere though. When I choke down the intake (partially cover intake tube with electrical tape), it runs significantly better but still tops out around 45 bmph. If I had a tiny tear in the diaphragm would it cause this condition? I have also checked the vacuum hoses and made sure the intake manifold is tight. Any other suggestions?

A tear would do it, because the slide would lose vacuum and never fully lift.

I pulled the intake and checked the slide with a mirror at full throttle and it raises completely. I bypassed the fuel filter to make sure it wasn't restricting flow but still have the same problem. I appreciate any other advice!

Please don't take this the wrong way, but have you run the VIN through the genuine's vin checker to make sure it is a 125, and not a 50. The seller may have replaced the 50 sticker with a 125 one.

I know the previous owner personally and saw the scooter the day he bought it. It's a 125. Also, I changed the oil and filter on it last week, so there's that. Thanks for thinking outside the box!

Okay, you know the diaphragm is working like it should. You restrict it on the air filter side and it runs much better. It looks like your problem is being caused on the back side of your carb. Do you know any other 125 owners in your area? It would be handy if you could sit yours side by side with the seat buckets removed. You need to re-trace the vacuum hoses and connections from the air box. you've got me stumped. The 125 is really a pretty simple beast.

After replacing the air/fuel adjuster o-ring and soaking the carb, I still have the same problem. When I removed the carb the first time, I had also removed the intake manifold. When i replaced it, I guess I pinched that o-ring and it now has a cut in it. I tried rtv sealant to fix it but that didn't help and I doubt I made a good seal. I will replace that hopefully that will fix it. If that doesn't work, if anyone is in the market for a Buddy 125 that runs like a 50, I've got your scooter!

Are you sure no work was done on the cvt prior to your purchase? Maybe some wrong sized rollers/sliders were installed? A flipped slider or two? Nut's not torqued all the way??? I'd be double checking your back end.

Replaced the o-ring and still have the same problem. As I said, I know the previous owner (my best friend) and he says the scooter has never been worked on other than the first oil change. All indications point to running very lean. I know the auto-cocks can be a problem and that's the next part I will replace (not getting enough fuel instead of too much air). If that doesn't work, maybe I'll get desperate and open the CVT.