Apex loss of power

[jhi]

We have a apex 50 that after 5-10min into a race it doesn't hardly even want to pull itself let alone the rider. it was a new motor with stage 6 jug, porting done, PVL ignition, koso clutch, keinan carb, jetted at 112 main/58pilot. uni pod filter, koso intake, ect. we put the stock clutch back on, no change, tryed different mains/ pilots, no change, sent the ignition in to PVL and they said it's OK. It has gotton worse as we go to each race. I'm so baffled it isn't funny. Has anyone had this problem or can someone point me in a new direction? thanks jeff

[nastynotchback1]

When was the last time you changed the torque spring?

[jhi]

We switched torque spring, tryed 1000 and 1500, and new red clitch springs, no change. thanks jeff

[cik orange]

have you done a compression check

[jhi]

It has done this since i had the motor built new. it has 10 hrs on it total right now. it has gotton worse since we first put the motor in. now i have to push him if i want him to move at all. the quad is at a shhop right now and the shop foreman says he has another on in there right now doing the same thing. i'm not trying to undermine him i'm just trying to figure it out to help. the motor was built by a very reputable builder that is why i guess i've never questioned the motor. i'll call the shop and ask them to do a comp. check. thanks, jeff

[redonkulousruntsracing]

I wish you the best of luck. I have been posting for months with the same problem on my sons 50. After 4 motors, 4 carbs, 3 totally different clutch setups, several gearing changes I have got nothing. I could take a top end or clutch set up off a friends quad and put in on my sons quad and there would be a 2 to 3 second difference in 300 ft. times. Put the stuff back on my friends quad and his runs fine. The quads are 09 50's with similar work done and the same gearing and tires setup. His quad will run 9.55-9.75 seconds, Seth's runs at best now 11.95-12.45 seconds. He put my top end and clutch setup on hid kids quad and run a 9.80?????????
The problem has gotten worse as the season wears on and I keep having to back off timing and re-jet because its overheating. 230-250 degrees, the radiator has been boiled out and we use Engine Ice. I tried the Stage 6 water pump, but with the stock one in ran longer before it would overheat. Right before I yanked it and sent it away it was doing the same thing, barely making it off the track. Let it set for a few minutes, it would make 2-3 good laps then crap out again so it is gone now, and dont know when it will return. Good luck with your problem and keep us posted if you find the problem.

[jhi]

got a reply yesterday about my problem. i started with a 70cc engine and had it built. the person that replyed said that 50cc and 70cc transmissions are different gearing so we are going to try to change the front and rear gears to see if it gets better. he feels that the motor will pull it at first then the clutch will begin to fail. it does sound like my problem. when we get done with a 30min hare scramble, the drum is shot. he also told me that possibly when the motor was built, that the rings maybe to tight and as the motor warms up that the rings expand.

[cik orange]

pm'd you both