PLEASE HELP! Slow acceleration uphill after belt replacement

hungryeddy · Post by **hungryeddy** » Wed Sep 03, 2014 4:46 pm

Long time lurker first time poster here. Love this site! Just that it makes me spend more than i hoped I would on my scoot haha. anyway i'm hoping you can help with an issue i'm having.

My platform:

2006 Buddy 50cc
7g sliders
1000rpm blue clutch springs
1.5k yellow contra spring
70cc auto tech kit
82 main jet
@ 5,280' elevation
i'm about 160 lbs

I got this scooter as a not running crashed to pieces $300 deal on craigslist. little by little this thing has seen a night and day improvement in general appearance and performance as well.

After it needing a new fork, carb, and a bunch of other little things, I had it running pretty awesome. Especially after the contra spring upgrade. It would pull real hard at 1/4 throttle to really get me going (which is great for hills here).

However last night I got a few extra parts in the mail so I installed what I could when i got home. It was missing the under seat middle plastic cover so i installed that, and it had an aging belt so i installed that.

Installation when great but when i got on the scooter and took off it started hesitating at low rpms. it bogs on hills now if i don't slowly give it throttle. if i WOT right off the line it will bog out until i let go of the throttle and slowly accelerate. I'm not really sure where to start on this one since it was running fine right before the belt replacement.

PLEASE HELP!! thanks in advance.

DeeDee · Post by **DeeDee** » Wed Sep 03, 2014 6:35 pm

Did you pull out and re-install your sliders? If so, ensure they are in the correct way. Take it back a part and compare your new belt next to the old one. Put the old one back in and see if it is fine. IF you replaced a factory belt w/ a factory belt, it has to be something other than the belt.

hungryeddy · Post by **hungryeddy** » Wed Sep 03, 2014 6:42 pm

thanks. I'll check the sliders tonight but i thought i was being careful not to move the variator out of place keeping pressure on it while i installed the belt. maybe a slider came out a little and its not letting it seat right or something.

I did order the PGO belt since no other companies seem to make them in the size for the buddy.

hungryeddy · Post by **hungryeddy** » Fri Sep 05, 2014 12:12 am

So the sliders are fine in the variator. I'm left scratching my head on this one.

has anyone ever experienced a snapped contra spring or something?

I really would like to get more out of it. its more slow on hills than it should be for a 70cc and i know because this very same bike has impressed me before. I would like to get it running awesome again.

hungryeddy · Post by **hungryeddy** » Fri Sep 05, 2014 12:12 am

So the sliders are fine in the variator. I'm left scratching my head on this one.

has anyone ever experienced a snapped contra spring or something?

I really would like to get more out of it. its more slow on hills than it should be for a 70cc and i know because this very same bike has impressed me before. I would like to get it running awesome again.

lovemysan · Post by **lovemysan** » Fri Sep 05, 2014 2:30 am

It sounds under jetted to me.

hungryeddy · Post by **hungryeddy** » Fri Sep 05, 2014 3:22 pm

didn't think of that. i have a bunch more jets i can play with. someone told me i wouldn't even have to rejet due to elevation and the 82 was the smallest i had in my jet kit.

BuddyRaton · Post by **BuddyRaton** » Fri Sep 05, 2014 4:24 pm

Did you compare the size of the new belt to the old one? PGO makes more than one size. I bought a Blur cheap because it didn't have much power. It had the wrong size belt in it. Maybe you ordered the wrong one or they sent the wrong one.

If you still have the old belt have you tried reinstalling it?

Did you make any other changes to the motor or trans from when it was pulling well?

While you were in there did you clean the clutch?

I'm just trying to come up with some ideas.

lovemysan · Post by **lovemysan** » Fri Sep 05, 2014 5:08 pm

I'm just guessing on the jetting. I assume your running a stock pipe. You could slightly restrict the intake and check for an improvement or Toss an 85 jet in for testing. I always jet rich for summer riding.
Once I installed a Kevlar belt I lost a lot of revs off the line. It seemed to bog the engine. After a few miles it slowly went back to normal. Possibly the belt needed some type of coating worn off. make sure your variator is opening freely and not getting stuck or binding.

hungryeddy · Post by **hungryeddy** » Fri Sep 05, 2014 7:59 pm

thank you for your comments and suggestions. I did confirm visually the numbers on the belt and held them side by side. I have not changed the belts out again but I will try that tonight.

No other motor or transmission changes.

I did not clean the clutch when i was in there but i will do that as well.

If this doesn't work I will toss in the 85 jet I have. I was also thinking maybe there was a coating on it but its been on there for about 65 buddy miles so...

I will also check for binding in the variator. I'm about ready to try anything now.

i have a feeling my problem lies in the clutch. The contra spring i ordered was a cheap chinese one... maybe theres a defect in it? maybe something isn't moving as it should because the difference with the new belt was night and day. I'm definitely going to toss the old one on there to see if that's really the issue.

DeeDee · Post by **DeeDee** » Fri Sep 05, 2014 9:13 pm

Did you replace the contra spring at the same time you did the new belt?
I don't know, but 1500 may be too stiff for the stock engine. You need to take the new pieces off and put the old ones back on. IF you regain your performance, start putting the new pieces back on one at a time until you hit your problem again.

hungryeddy · Post by **hungryeddy** » Sat Sep 06, 2014 1:07 am

well the engine is 70cc now... is the yellow spring too much??

the contra spring went in about a week before the belt did. the issue happened after the belt was replaced.

lovemysan · Post by **lovemysan** » Sat Sep 06, 2014 12:53 pm

Have you adjusted the idle mix screw? Not the idle speed, that's a black knob sticking out at a right angle from the carb. If you stand on the kick start side looking down its on the left side, near the intake end. It is in the 10:30 position or facing out at 45 degree angle. It's brass, some of them are shaped like a smooth brass plug. I used to picks to spin mine out and slotted it with a Dremel cut off wheel.

hungryeddy · Post by **hungryeddy** » Sun Sep 07, 2014 10:51 pm

i'm about to pull my hair out! i can't get this thing pulling like it was before!

i've tried an 85 jet
i've taken apart the clutch and variator and cleaned and made sure they were installed correctly.
i didn't have the old belt so i couldn't try that.
it idles beautifully
i've tried various air configurations (took out the tube inside the air box, loosened screws)

i would really love for it to rev high as soon as i get on the throttle as it did the day i installed the 1.5k contra. it would rev high and have a high pitched sound and not go anywhere until it really had some power.

now it wants to take off the second i pull on the throttle and it sounds lower pitched. I don't understand how just changing the belt could give me this problem.

charlie55 · Post by **charlie55** » Sun Sep 07, 2014 11:10 pm

hungryeddy wrote:i'm about to pull my hair out! i can't get this thing pulling like it was before!

i've tried an 85 jet
i've taken apart the clutch and variator and cleaned and made sure they were installed correctly.
i didn't have the old belt so i couldn't try that.
it idles beautifully
i've tried various air configurations (took out the tube inside the air box, loosened screws)

i would really love for it to rev high as soon as i get on the throttle as it did the day i installed the 1.5k contra. it would rev high and have a high pitched sound and not go anywhere until it really had some power.

now it wants to take off the second i pull on the throttle and it sounds lower pitched. I don't understand how just changing the belt could give me this problem.

OK, that last paragraph is a great clue and indicates that your clutch is engaging the bell as soon as you blip the throttle. So, it has to be something in the variator - clutch interplay.

What I would do is put it up on the center stand, remove the belt cover, and observe the movement of the belt as you gradually increase the throttle. If it's jumping to the outer circumference of the variator just as soon as you start to accelerate (or even at idle), then something's out of balance.

hungryeddy · Post by **hungryeddy** » Mon Sep 08, 2014 12:16 am

i will upload a video shortly but to me (i'm very new to scooters) it looks like its going smoothly.

however while on the center stand it works great and doesn't bog. it is going uphill where you notice it the most because the engine won't have that 2 stroke wah sound. sounds like a 4 stroke almost.

riding on a flat road the rpms will be slow to increase but once it gets to a certain rpm it'll pull better (still not as nice as before)

I really want to get this fixed because i rely on my scooter to take me to work

PeteH · Post by **PeteH** » Mon Sep 08, 2014 12:37 am

If it's four-stroking under load, you may have a fuel/air problem rather than just a mechanical one - only firing on every other revolution. I'll try to find this one YouTube vid that gives a good demo.

lovemysan · Post by **lovemysan** » Mon Sep 08, 2014 12:54 am

How do the clutch springs look? One could be bad, broken or weak. Sometimes the get hot and loose there strength.

hungryeddy · Post by **hungryeddy** » Mon Sep 08, 2014 1:08 am

I will check the clutch springs but those are new too.

here's the vid of my transmission in action:

https://www.youtube.com/watch?v=_lxuJ4R ... u_dH6oDmTA

hungryeddy · Post by **hungryeddy** » Mon Sep 08, 2014 1:44 am

it runs great when its cold. once it warms up it starts bogging a lot more.

also when it idles for more than a minute or so it will bog like hell for a good 20 seconds on the throttle.

lovemysan · Post by **lovemysan** » Mon Sep 08, 2014 4:06 am

Your video is private

lovemysan · Post by **lovemysan** » Mon Sep 08, 2014 4:18 am

Running fine cold then bogging when warm is a classic sign that the fuel mixture is incorrect. Understand that when cold the auto enricher is providing additional fuel to the idle circuit. The idle mix screw controls idle to 1\4 throttle and effects the transision from idle to wot. You adjust the idle mix when the engine is at warm idle. Your looking for the fastest idle speed. You also fine tune the crispness of the throttle response with the idle mix. Also it sounds like you may have a plugged pilot jet as well, it may be worth checking as the pilot jet will also effect the 0-1/4 throttle.