• Purchased an old Helix buggy, slowly fixing problems. Poor top speed.

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 #11338  by JoeNova
 Wed Jan 24, 2018 6:19 pm
I purchased a 150cc Helix buggy for $200. He said it didn't run because it had no spark.

First thing I did was completely disassemble and clean the carb. Next, I noticed it had an AC CDI and it was wired for a DC CDI. I replaced the CDI with a new DC unit and the spark plug and managed to make it run, although VERY rough. Next, I adjusted the intake/exhaust valve @ .004 lash. Now it runs super smooth. I ran some Seafoam through the gas tank and the intake manifold via the vacuum hose as well.

It still wouldn't go over 5 mph. Extremely lazy to get going. I replaced the entire clutch assembly today. That helped a little but not much. I decided to check the gear oil. It had almost NONE. I topped it off and now it runs and accelerates fine, but will only do 15-17 mph. The buggy is rated for 37-39. Honestly anything around 30 mph would make me very happy.

Assuming the gearbox wasn't damaged for being ran without any fluid, I think my only other thing to check is the variator? The belt looks GOOD. The rollers look fine, the plastic clips are all there, no wear on the bushing. The only 2 things I can see on the variator are that there is a slight groove worn in the face of both cones near the outside, and the backside of the variator where the rollers sit looks like it has been polished by them. Other than that, nothing.

My new variator arrives tomorrow. Just a cheap OEM replacement. What else should I be looking at for reduced top speed if that doesn't fix it?
 #11340  by PGH
 Thu Jan 25, 2018 5:47 pm
Make sure the CVT belt is the correct size for your short case GY6 engine. The 800+ sizes are for the longer scooter engine cases.