Modern Buddy

Practicing for the motorcycle skills test I did a LOT of slow start-stop driving in a parking lot. Now, I notice my buddy 125 jerks (lurches forward, catches) when I take off from a stop. Don't know if these two things are related, but I'm concerned about the transmission. Once the scoot is moving a bit it is smooth. It has 4200 miles. I changed the gear oil about one yr. (1000 miles) ago. Any ideas?

Does the engine sound normal when it does this, or does it sputter (lose power)? If the engine sounds normal, then the problem could be the clutch slipping then catching. Sometimes when too much dust/dirt builds up inside the transmission cover due to belt wear and clutch shoe wear, the clutch can slip a little before grabbing. The fix would be to remove the trans cover and blowing out the dust with an air hose making sure to get inside the clutch bell too.

Babblefish--the engine does sound normal. I, too, am thinking it's the clutch.
I've never removed the transmission cover. I've seen some good videos on replacing rollers, belt, clutch, but I've not done this. Would I need a power air hose to clean things out?

You can remove the CVT cover with very little mechanical ability. It requires an 8mm socket. Remove the cover and have your scooter on it's center stand. Have a friend start it up and sit on it while you watch the primary and secondary pullys. At idle the belt will be low on the front pully and high on the rear pully (clutch). Gently increase and maintain throttle. See if the travel on front and rear is smooth. The belt should move toward the outer edge of the front pully, and the inner, smaller part of the rear pully. You don't need air to clean out the belt dust. I use a one inch chip brush and paper towels. At 4,200 miles, I wouldn't expect a whole lot of belt dust. Your next step is to remove the variator, and inspect the rollers, then remove the clutch and see if the clutch pads are glazed. Unless you beat the tar out of your scooter, I would think all the stock components should still have plenty of life left.

When is the last time you: checked the valves, replaced the spark plug, changed the air filter? Might be due for a thorough tune up.

ucandoit wrote:Babblefish--the engine does sound normal. I, too, am thinking it's the clutch.
I've never removed the transmission cover. I've seen some good videos on replacing rollers, belt, clutch, but I've not done this. Would I need a power air hose to clean things out?

Compressed air would make cleaning out any belt/clutch dust from inside the clutch bell a lot easier. No offense, but if you're a "heavy" rider, the clutch would have to "slip" more to get everything moving, so there's a possibility that the clutch shoes and/or bell is glazed which could cause a hurky jerky take-off.

DeeDee and Babblefish: I bought the scooter with 3000 miles on it and have put on 1200. I don't know the history of the scooter. I've replaced the spark plug, adjusted the valves, cleaned the carb., new air filter, oil changes, gear oil change, etc. I weigh 120 lbs. and ride super cautious -(Am 61 yr. old woman and not comfortable with much speed, but I love riding and learning the mechanics, though I'm tentative.) I'll remove the transmission cover and watch the belt as a helper works the throttle. I really think this is related to my doing repetitive very slow starts while practicing for the motorcycle skills test. While I was doing it I thought, this probably isn't good for the scooter--- Like riding the clutch all the time. The problem showed up just after that. Maybe I'm wrong. Maybe the clutch pads are glazed or the bell is not right. Not sure how to correct that and getting those dreaded nuts off the clutch and variator will be an adventure. lol For peace of mind I'd like to learn to check the condition of the belt.

Also, I really appreciate your support and suggestions.

Safety eyewear if you're inspecting a running CVT with the cover removed.

ucandoit wrote:DeeDee and Babblefish: I bought the scooter with 3000 miles on it and have put on 1200. I don't know the history of the scooter. I've replaced the spark plug, adjusted the valves, cleaned the carb., new air filter, oil changes, gear oil change, etc. I weigh 120 lbs. and ride super cautious -(Am 61 yr. old woman and not comfortable with much speed, but I love riding and learning the mechanics, though I'm tentative.) I'll remove the transmission cover and watch the belt as a helper works the throttle. I really think this is related to my doing repetitive very slow starts while practicing for the motorcycle skills test. While I was doing it I thought, this probably isn't good for the scooter--- Like riding the clutch all the time. The problem showed up just after that. Maybe I'm wrong. Maybe the clutch pads are glazed or the bell is not right. Not sure how to correct that and getting those dreaded nuts off the clutch and variator will be an adventure. lol For peace of mind I'd like to learn to check the condition of the belt.

You're very welcome, I like to help when I can. I'll bet the real reason for the problem is all the burnouts and streetlight racing that you're doing, lol! Just kidding.
You're probably right about the "riding the clutch" thing. Taking the clutch bell off isn't the easiest thing to do without the proper tools. The hardest part is removing the nut that holds the bell in place...its on there tight. If you're lucky, a bit of work with sandpaper on the clutch shoes and the friction surface of the clutch bell will fix the problem. Worst case would be a warped clutch bell from over heating. If so, the only fix is to replace the clutch bell.

It's too bad we're so far apart, otherwise I'd be more than happy to give you a hand fixing the problem.

Try deglazing the clutch. Hold the rear brake tightly and give it full throttle for a second. You may have to do it more than once.

I had the same issue. the dealer replaced the clutch under warranty and it has been riding fine for 1000 miles now.

I appreciate the reminder to wear safety glasses. I've seen some youtubes on how to get that nut off to remove the clutch bell. And I may try holding the rear brake and turning up the throttle to de-glaze the bell. I think the clutch will be in good shape, but we'll see. Thanks for all the info. I have plenty of things to try and check out. Eventually I would need to learn how to replace the rollers, belt, etc. thank you all for the help and I'll cut down on the street racing. lol.

Your original description sounds like either a build-up of belt dust in the CVT, worn rollers or both. Could be a glazed clutch and/or bell but the most likely culprit is the rollers.
You say you noticed the change after a lot of start-stop practicing and the scooter has 4200 miles. If it's never had the rollers replaced, it's due; particularly with the symptoms you describe.
Plenty of great how-to's in the tech section on how to get in there. I was always able to get the variator nut loose with a strap wrench and a socket. I torqued it back to specs and put blue loktite on after an incident where the nut backed off on it's own.
I understand a lot of folks live in apartments or otherwise don't have access to a workshop type environment or the right tools. I've always thought it would make for a great get together to have local scooter clinics at someone's house to sort out those things. I think BuddyRaton used to do an occasional such.