Tomberline Crossfire 150r, very hard to push and engine dies when stopped
 

I recently rebuilt the top end and readjusted the valves yesterday on my Crossfire 150r. It runs great but I have two big problems. When I push the go kart it feels like the engine is trying to hold the wheels still but I can still move it with a lot of effort. When it's being pushed, I can see the chain shake every couple of inches I push it like the engine is grabbing it. I've tried changing the gear oil and motor oil, but it didn't help. My other problem is that when I'm driving the go kart and come to a stop the engine dies. I have to brake extremely carefully and slowly in order to keep it running. I think this may be related to the pushing issue too. Also the rear brakes don't slow it down because this issue. I have no idea what the problem could be.

Thanks

Are you sure everything was lined up correctly and valves assisted while crank was in correct position?

It has had this problem far before I've adjusted the valves and rebuilt the top end.

check this
 

you lost me after you asked if everything was lined up. lol sounds like you have a problem with either the belt is too short, or maybe broke, binding or your variator is binding. pull the side cover off and check all that is belt related behind the engine cover. :cheers:

also chain too tight would cause this too.

Are your clutch and variator disengaging?

I took the belt cover off and drove it around so the problem would happen. It looks like either the variator or clutch is stopping the engine when I come to a stop. Then I tried to push the go kart while the belt was tightened from the stopping issue, and it looked like the clutch wasn't working properly. When I pushed it, the belt stayed in place and the outer piece of the clutch was moving in a jerking way, like something inside was keeping it from moving smoothly. I don't know if it is supposed to do this or not but if it is, I thing the variation may be too tight on the belt since it moves with the engine.

it should free wheel on the variator

The belt is fairly free around the variator but it is petty tight around the clutch. I can pull the clutch apart so the belt is under less tension, and the go kart moves freely. I think the clutch my be the problem

I bet (1) the variator is hung up , I bought one once and the guy before me had the rollers in end wise , wouldn't open completely or close at all , and the nut from the exhaust stud had fallen off and wedged in the driven clutch preventing it from opening ( they were the equivalent of two fixed pulleys ) (2) The belt is wrong ( too short ) or (3) The canooter valve is faulty . :party:

Disregard previous post , I forgot the belts under tension and the centrifugal clutch . I was applying your symptoms to a tav 30 type . The problem with mine as previously mentioned caused no variable speed , but not sticking . :stupid:

survey saysssssssssssssssss ding, we may have a winner lol

I would say it's the variator. I've learned when putting them back inside the case, and sliding it down the shaft, you got to keep the entire back half of the variator tight, and closed, or one or more of the rollers, or sliders can get set in wrong location when you do the final tight down will cause many different problems. Including what you are describing.
If at any point while putting it back on, and I might think, the back of variator wasn't closed the entire time. I'll stop, and check the sliders, and do it over again. Just easier, making sure, instead of tearing the entire thing back a part after all together, and belt is on.