Buddy 170 - CVT issue causing poor acceleration?

[mukaiboston]

I am not really mechanically knowledgeable when it comes to engine and fuel issues so bear with me.

In the fall, I noticed that my scooter had difficulty accelerating from a dead stop. I would pull the throttle pretty much wide open and it would chug from low RPMs until the speed got up to about 20mph and the rpms got fast enough. Then it would run smoothly all the way up to 60mph. The problem was extremely intermittent and random.

I know it's a CVT, but the feel and sound is exactly like if you were trying to accelerate a car from 2nd gear instead of 1st. So it's sounds like a CVT problem although with the issue occurring so randomly, I don't want to take it to the mechanic if I can't replicate the symptoms because then they will just hold on to it and charge me for the time.

During the winter months, the problem was extremely rare and only happened once. I figured it was running bad because the battery didn't have the amperage necessary to drive the fuel pump. (The battery was replaced over the winter due to low amperage and unable to start to the scooter in the cold).

Over the weekend, we pretty much had identical days with temperatures around 16c or 60f. Saturday, I rode 30+ miles with no issues, but Sunday, the problems started again. It's very scary riding with bad acceleration. I tired pulling off the road so I could film the issue with my phone but, both times, the problem went away.

Things I have done so far:
-Checked spark plug
-Motor oil change
-Changed battery
-Changed air filter

Other important info:
-Scooter has 17534 miles on it
-It may be important to note that I started dropping a shotglass amount of seafoam in the gas tank with each fillup starting in the fall. The last time I filled the tank was Saturday right as I was nearly home. So the problems started again the next day. Seafoam is supposed to fix things, not break them, but I think I'm going to stop using it now that it's warmer just to eliminate it as a possible cause.
-I have had minor issues with the rear brake sticking and am planning to have that adjusted next time I am at the mechanic.

[Yalzin]

Have your roller weights, belt, variator, and clutch checked. Especially if you haven't with that kind of mileage.

Possible issues:

-Worn/flat roller weights
-Work Belt
-Broken Variator Slides
-Worn or broken clutch

[DeeDee]

Have the valves ever been checked? The exhaust valve on my 170i usually needed adjustment (too tight) every check. A symptom would be poor performance as the engine heats up.

[skully93]

Agreed. I'd definitely check the clutch/entire transmission at that point.

When was your last belt/roller weight change?

[mukaiboston]

I don't believe the transmission has ever been checked, but I guess I will have to see about taking it in. I just want to make sure that this is the most likely issue before taking it there. Any idea why the problem is so random? This definitely never happened when the weather was colder.

[DeeDee]

You should be more concerned with the valves than the transmission. If you're belt breaks, you'll be inconvenienced when you are left stranded. If you fry an exhaust valve, start opening your wallet. At almost 18,000 miles that scooter should be on it's 2nd or 3rd belt and should have had 4 valve adjustments by now. Have you owned it since new?

[babblefish]

Not to second guess anyone here, but if the problem is random and the scoot has that many miles and you've never had any transmission work done, the first thing I'd have checked are the rollers in the variator and the belt. I'm guessing flatten rollers are a big part of the problem, especially if only a couple are really bad.
Valve adjustment issues are usually not random and do not come and go. Plus the symptoms you describe doesn't sound like a valve issue. Either way, bring it to a scooter mechanic (not motorcycle) and have it checked out. Most motorcycle mechanics (not all) are not familiar with the inner workings of a scooter transmission and wouldn't know what to look for.

[mukaiboston]

I keep asking about valve adjustments and everyone seems to have a different opinion on when they need to be done. The parts guy at my mechanic even said don't worry about it unless you see symptoms.

Now for the CVT maintenance, I never had this done and I don't think the previous owner did either because I don't recall seeing it in the reports. I wonder why the mechanic didn't inspect it as far as the regular inspection goes. I bought the scooter used in November 2014. I'll call the mechanic tomorrow morning and see if he can take it but, I don't know. They seem to be frequently short on parts and, now that it is spring, there is going to be a backup of work most likely.

Is this scooter still safe to ride or should my next ride be only straight to the mechanic? I don't want the belt to snap or something else to go horribly wrong. From what people are saying it looks like I should get it down there rather quickly.

[babblefish]

I keep asking about valve adjustments and everyone seems to have a different opinion on when they need to be done. The parts guy at my mechanic even said don't worry about it unless you see symptoms.

Now for the CVT maintenance, I never had this done and I don't think the previous owner did either because I don't recall seeing it in the reports. I wonder why the mechanic didn't inspect it as far as the regular inspection goes. I bought the scooter used in November 2014. I'll call the mechanic tomorrow morning and see if he can take it but, I don't know. They seem to be frequently short on parts and, now that it is spring, there is going to be a backup of work most likely.

Is this scooter still safe to ride or should my next ride be only straight to the mechanic? I don't want the belt to snap or something else to go horribly wrong. From what people are saying it looks like I should get it down there rather quickly.

From my experience, valves that are too tight usually results in a rough idle and lessened low end performance that clears up at higher RPMs. Valves that are too loose will cause a ticking noise at idle and a slight decrease in top end performance. Miss-adjusted valve clearance problems are either there or not and do not come and go.

Mechanics who do not check the rollers in a variator are either unfamiliar with them or just lazy. In order to inspect the rollers, the variator has to be taken apart. Then, one needs to know what a good roller is suppose to look like and what constitutes a bad one. It also doesn't hurt to weigh each roller to make sure their weights are within 10% or better of each other.

Other than the risk of the belt breaking, in which case the scoot would just stop moving, riding it shouldn't be a safety hazard to yourself, but could cause more damage to the engine. Of course, you could be unlucky and the belt could break, jam-up on the rear clutch pulley and lock the rear wheel up. But, the good news is the clutch should release once the clutch pulley stops turning, thereby allowing the rear wheel to spin free again.
Just for peace of mind, I'd bring the scoot to a qualified scooter mechanic...

[mukaiboston]

I rode it (lugging nearly all the way) to the mechanic and dropped it off. They are supposed to give me a call today but they've said that before and gotten backed up on other jobs. I told them to go ahead and check the valves for adjustment as long as they are working on it. If indeed it's just the rollers and belt and a valve adjustment, I would hope the actual work wouldn't take too long as this is my only vehicle and I'm anxious to get it back.

When I dropped it off, I had her pull the maintenance records and she said the previous owner never had CVT or valves checked. She also said she was very surprised that I had made it nearly 18000 miles on the original stock belt and rollers and only started having engine problems now.

Also, while I was taking it to the mechanic, I was listening very closely to the engine noises. I do recall that when you normally brake, you can hear (I think) the clutch letting go. It usually sounds like a soft thunk and then the engine goes to idle. Well, I didn't always hear that thunk and it felt like maybe it was stuck in the wrong position. I found that grabbing the brakes repeatedly at a stop or going very slow seemed to force it back into position, but I'm not sure.

I'll update when I get it back so people know exactly what was wrong with it.

[DeeDee]

Just so you know. Those valves need to be checked on a stone cold motor. If they call you within the day telling you they have checked the valves, be skeptical. If you are in fact on the original belt and rollers, that has to be close to some type of record. At any rate your scooter should scream when you get it back.

[babblefish]

What DeeDee said, engine needs to be cold when checking and/or adjusting the valve clearances.

The clutch will not always release when you roll off the throttle. It will sometimes remained engaged until your speed drops to a certain point. The clutch works by centrifugal force, so if the rear wheel is spinning fast enough, the clutch shoes will remain engaged. This is helpful when going down steep hills because it allows the engine's compression to slow the scoot.

[jrsjr]

When I dropped it off, I had her pull the maintenance records and she said the previous owner never had CVT or valves checked. She also said she was very surprised that I had made it nearly 18000 miles on the original stock belt and rollers and only started having engine problems now.

She isn't the only one who is surprised. I bet the rollers are way past "worn" and more in the realm of "disintegrating." 18K. Wow. That just doesn't seem possible... I wonder if the previous owner serviced the CVT him/herself and that's why the dealer has no records?

[mukaiboston]

The clutch will not always release when you roll off the throttle. It will sometimes remained engaged until your speed drops to a certain point. The clutch works by centrifugal force, so if the rear wheel is spinning fast enough, the clutch shoes will remain engaged. This is helpful when going down steep hills because it allows the engine's compression to slow the scoot.

Exactly this. This is what I stopped feeling after a while. I think the clutch shoes were remaining engaged even when slowed to a stop.

[mukaiboston]

I wonder if the previous owner serviced the CVT him/herself and that's why the dealer has no records?

When I bought the scooter, he told me he didn't do any maintenance himself and always took it back to the dealer so if they don't have a record, I can assume it was never done.

[babblefish]

The clutch will not always release when you roll off the throttle. It will sometimes remained engaged until your speed drops to a certain point. The clutch works by centrifugal force, so if the rear wheel is spinning fast enough, the clutch shoes will remain engaged. This is helpful when going down steep hills because it allows the engine's compression to slow the scoot.

Exactly this. This is what I stopped feeling after a while. I think the clutch shoes were remaining engaged even when slowed to a stop.

If the clutch shoes where to remain engaged when you came to a stop, the scooter would first stutter and buck then the engine would die because the rear wheel is still connected to the engine. Does it do this?

[jrsjr]

I wonder if the previous owner serviced the CVT him/herself and that's why the dealer has no records?

When I bought the scooter, he told me he didn't do any maintenance himself and always took it back to the dealer so if they don't have a record, I can assume it was never done.

Wow. In that case, the CVT has never been serviced in 18,000 miles. Babblefish has a good question above, but at this point it's academic because I think pretty much every wear item in the CVT will probably need to be changed including the rollers, the belt, and the clutch pads.

May the replacement parts last as long as the originals did!!!

[mukaiboston]

If the clutch shoes where to remain engaged when you came to a stop, the scooter would first stutter and buck then the engine would die because the rear wheel is still connected to the engine. Does it do this?

No, that's not it. It think the plate with the clutch is not moving back into its idle position so the "gear" is set too high upon takeoff.

[BuddyRaton]

Listen to the others. Rebuild the CVT, adjust the valves, change the plug, oil, gear lube and do all the other maintenance that has been missed.

That will probably take care of your problems.

[jrsjr]

If the clutch shoes where to remain engaged when you came to a stop, the scooter would first stutter and buck then the engine would die because the rear wheel is still connected to the engine. Does it do this?

No, that's not it. It think the plate with the clutch is not moving back into its idle position so the "gear" is set too high upon takeoff.

I've never seen it personally, but I've been told that it's possible for the clutch components to get out of position so that they drag (or won't engage, depending on orientation) regardless of engine speed. Again, with such high mileage, all bets are off.

If I might ask a favor, if you have a good relationship with the folks at this shop, I would really like to see photos of what they find when they pull the CVT parts out. I bet I'm not the only one here.

Thanks! And Good Luck!!!

[babblefish]

If the clutch shoes where to remain engaged when you came to a stop, the scooter would first stutter and buck then the engine would die because the rear wheel is still connected to the engine. Does it do this?

No, that's not it. It think the plate with the clutch is not moving back into its idle position so the "gear" is set too high upon takeoff.

I think you're confusing the variator (attached to the engine crankshaft) and the clutch (attached to the gearbox at the rear wheel). The variator is not a clutch as it never releases and is always engaged. All it does is vary (hence it's name) the drive ratio between the engine and the gearbox/rear wheel. But yes, if the vaiator does jam up, it could cause the scooter to try and start off at too high of a gear ratio. All of this conjecturing isn't going to fix it though. Just bring the scooter to a mechanic and let us know what he/she finds.

[BuddyRaton]

If I might ask a favor, if you have a good relationship with the folks at this shop, I would really like to see photos of what they find when they pull the CVT parts out. I bet I'm not the only one here.

Thanks! And Good Luck!!!

I would like to see photos also. Curious what the parts look like after that many miles. Let the shop know that the photos will be on MB.

Give them a mention in the thread for a few photos is a win for everybody.

If not you could always ask for the parts the would dispose of.. it will also give them incentive to do a great job!

[DeeDee]

With that high of miles, it's not uncommon for the big contra spring to wear out. It will become so weak it will engage the rear wheel at low rpms. If the scooter is up on the center stand, and you see the rear wheel spinning like crazy this is a sign. Another sign will be a real rough idle at the stop light that lessens when the rear brake is on.

[mukaiboston]

Thanks for all the advice. There may be some rough idle but not really noticeable. The only real issue has been the acceleration. I don't want them to touch any fluids as I religiously take care of that myself and I don't want them mucking up my routine.

How long does it take to replace the weights and the belt and do the valve adjustment? Just asking because I don't really trust these people and I want to keep a close eye on what is going on.

I dropped the scooter off Tuesday night and was told they would diagnose and call Wednesday afternoon. After three days of being patient, I called them today (Friday) to ask for an update. He says hold on and he'll go check. Calls me back about half an hour later with his speculation that the rollers and belt need replacing due to high mileage. I'm like, yes, we already know that and I want to know what the condition of the insides is. He says he'll call me back when they open up the CVT and look at it. Hmm...so they hadn't opened it yet? What the %$#@ has been going on these past three days.

Unfortunately, I'm used to this. I'm going to have to call them every few days to ask for status updates and document what they tell me. And when I call tomorrow, I'm going to ask them to save all the parts so I can examine them myself.

I think this should be done in a week if they have the parts, so if it drags on a month (which I am preparing to wait), I need to know if something unreasonable is going on. Seriously, it's like a daycare. I think we can all guess that they didn't do anything until I called them today inquiring on the status. This is the same shop that has told me twice that they would have a tire change done in a few hours and they call me right before closing to tell me they are done.

[DeeDee]

A tech that knows Buddy scooter should be able to do a whole CVT service and a valve adjustment in 1.5 hours max. Add 30 minutes if the clutch springs need replaced. At 18,000 miles they should probably just have the new parts sitting there ready to go in. I can't imagine there is much left in the way of useable parts.

[Wertles]

I found the valve adjustment, belts and sliders actually easier than fluid changes (absolutely no potential mess to deal with). This is something anyone with a tool box can handle. For a $20-30 investment in harbor freight tools, you can easily perform this service yourself with a little help from the tech section and save yourself all the aggravation of dealing with the shop that has you on the back burner. You can pick the parts you want to put in and save yourself money too. At that mileage, you can order a whole NCY or Dr Pulley upgrade kit and come out cheaper (and faster) than what they will charge you for sliders and a belt.

[DeeDee]

I second what Wertles has to say. The Buddy is an incredibly easy machine to work on. Do it yourself, take your time, watch the videos and ask for help if you need it. I guarantee you are more concerned with how your own scooter turns out than the $10.00 an hour kid who will be working on it at the shop.

[mukaiboston]

Sorry for the late update. It looks like the rollers are flat and don't even roll. They also said the belt and some other parts are worn too much and need replacing. From here its a matter of being able to order the parts from Scooterworks. I know I had to have an exhaust replaced last year and that took a few months to ship to the US, but the parts guy at the shop says they usually keep engine parts more in stock so, as long as scooter works has them, they can ship them over in a few days.

[DeeDee]

Please request the old parts back. When you're all done, post a picture. Good luck.

[jrsjr]

I know I had to have an exhaust replaced last year and that took a few months to ship to the US, but the parts guy at the shop says they usually keep engine parts more in stock so, as long as scooter works has them, they can ship them over in a few days.

Thanks for the update! The parts that your scoot needs should be in stock because those are normal wear-and-tear items. I expect you will be back on the road quickly.

(The exhaust thing - I wonder if that series of big typhoons that hit Taiwan last year interrupted parts delivery. I suspect that situation may have been a case of very unlucky timing)

Here's the good news! After they drop the new CVT parts in your scooter, the first time you ride it will be a revelation. Buddy scooters are famous for being zippy and fun to ride. I sincerely hope in a couple days you will zipping around with a giant smile.

[mukaiboston]

Face movable drive $18.85
Weight roller comp $20.28
Outer body comp, clutch $27.30
Ramp plate $7.15
Slide piece $2.76
Drive face $13.65
Belt $41.60

Labor costs $247.50

Virginia state taxes $7.90

TOTAL $386.99

[jrsjr]

Thank you for posting that up. Those are some worn CVT rollers for sure. Once of them them clearly had been riding on the metal for quite a long time. The belt is not as obvious until you compare it to a new one, then you can see how totally worn out it is. The labor charge is in line with what I expected from a Washington D.C. area shop. Everything is high there, so they have to charge enough to stay in business.

The question of the hour - How does it ride now?

[mukaiboston]

It feels like a new scooter. But did the photos of the worn out parts post? I uploaded them but now I cannot see them.

[DeeDee]

You win. I've worked on over 40 twist n go scooters over the years. That is by far the most worn out roller I've ever seen. Another testimonial to PGO's outstanding quality. I'd like to see what a Honda Metro's CVT looks like after 18,000 miles and zero maintenance. Thanks for the update.

[jrsjr]

It feels like a new scooter. But did the photos of the worn out parts post? I uploaded them but now I cannot see them.

Yes the photos posted. The most likely reason why you can't see them is that you are not logged in. Make sure you are logged in and let me know if you still can't see the pix.

Thank you for posting the pix and the follow up in this thread! An 18K CVT is one for the record books.

I am so happy that it rides like a new scoot.

[mukaiboston]

I think my CVT was having issues before but the problems happened so gradually, I just didn't notice the drop in performance.

The acceleration on this thing is crazy. I feel like I'm barely pulling the throttle and it's already up to 45mph. Several times, I've actually had to slow down because I thought I was doing 40mph and I was really approaching 60mph.

Also, that thunk sound I posted about earlier when the scooter slows down and "something" disengages. It turns out that sound was never supposed to be there. With these new parts, the scooter does not make that noise or that jerk movement when it comes to a stop. It simply slows down gradually and the rpms slowly drop.

The same goes for the acceleration. When I would accelerate before, I would hear the rpms rev and then the scooter would jerk forward. Not a rough jerk at all, but it definitely accelerates extremely smoothly now without lurching forward like that.

[jrsjr]

When I would accelerate before, I would hear the rpms rev and then the scooter would jerk forward. Not a rough jerk at all, but it definitely accelerates extremely smoothly now without lurching forward like that.

The design of all the parts in the CVT system is really extremely subtle and clever. By coincidence I happened to spend a few hours once with a guy who thoroughly understood just how amazing the engineering is behind all that stuff. He walked me through it and afterwards I was sort of awestruck. The CVT system is a mechanical analogue of the oriental concept of yin and yang. It even looks like it when it's running. Now you know how cool it is when it's working correctly

[babblefish]

Glad you got your scoot sorted out. Feels like a heavy weight off your chest, doesn't it?

[JettaKnight]

When I would accelerate before, I would hear the rpms rev and then the scooter would jerk forward. Not a rough jerk at all, but it definitely accelerates extremely smoothly now without lurching forward like that.

The design of all the parts in the CVT system is really extremely subtle and clever. By coincidence I happened to spend a few hours once with a guy who thoroughly understood just how amazing the engineering is behind all that stuff. He walked me through it and afterwards I was sort of awestruck. The CVT system is a mechanical analogue of the oriental concept of yin and yang. It even looks like it when it's running. Now you know how cool it is when it's working correctly

It's simple, yet complex.

I tried to do the math on it once - you have centrifugal force working against a spring - it's a rather nasty differential equation.

[jrsjr]

Glad you got your scoot sorted out. Feels like a heavy weight off your chest, doesn't it?

And perhaps a bit of weight out of your bank account, too. Sorry about that part.

[Syd]

Your closest dealer. If you don't know where a dealer is use this: http://genuinescooters.com/dealers.html