I have a built LT80 w/a ported CGR cylinder and it pulls hard on bottom and mid-range but it stutters bad on top. I don't know for sure if its a fuel thing or a spark issue? Does anyone know what to check? I have had coil checked and it checked out ok,so whats next? HELP!

 

How can I tell if I need a bigger carb.?

 

i doubt you need a bigger carb, do you still have the vacuum petcock? that may not be flowing enough fuel at high rpm. also have you pulled the flywheel and made sure there wasnt dirt/rust on the pickup coil/flywheel

im assuming the carb and air cleaner are good and clean

 

What's the compression?

 

I changed petcock to a non vacuum operated and plugged port on carb.I have cleaned off flywheel,new fuel filter,new stock carb and have took it apart and cleaned good. I have also tried a wide variety of main jets to see if it would make a difference with no luck.Its a 54.5mm cylinder thats fresh but I dont have a compression tester,i will try to check tomorrow and reply back with results. Thanks guys !!

 

get over to auto zone or parts store near you and pick up a decent compression tester, its a must have owning atv/dirtbikes, especially when you start modding them

 

compression was just checked in at 170 psi. I had Jack (LT80) to bore the cylinder this last winter and I have'nt had the time to get it all going until now.It done this missing deal before I sent it to Jack we suspected it was because the compression was around 125psi at the time? We race in atv rodeos around here and thats it.It just aggrivates the crap out of me and the boys cause they have to share the youngest ones.lol

 

Could my reeds cause this problem at high rpms or would bad reeds cause problems at all rpm's? just trying to find his problem,sorry so many ??

 

HELP!!!!!!! We have another rodeo sat.night and we need this one running.The LT80 my boys raced with last weekend has a Jack Moore built stage2 kit and we got 2nd place,which was real good there was an array of built apex 90's 1st place beat us by 1/2 a second so we need the extra power the other LT should have. Maybe we need Jack to do us up a national cylinder cause the boys handled the stage2 just fine.

 

Ahhha, today I took off the carb.to swap with another just to check and I seen that a small piece of the reed was broke off! could that be my problem?It can't be helping anything.Hey Jack,what do you charge for your custom reeds?