I bought a 2005 LT80, haven't been able to get it to run properly. Carb has been cleaned, compression and spark are both good, reeds look good, drained gas put in fresh premium, drained oil, put in fresh oil. Petcock seems to be behaving properly free flow on pri, no flow when on or on res. I can only get it to start by putting my hand over the front of the carb. I can also get it to start with it fully assembled if I elevate the front of the bike to my waist. Once I have it started, it will run as long as I'm giving it some throttle. When driving, it will bog down and max out around 7mph, then randomly open up and go full speed like there's nothing wrong with it. Won't idle when first started but after it has been running for a bit, it will stay running. Help!

 

Welcome to the forums.
IMO, It's in the carb. There has to be a flooding type issue. Shouldn't have to raise the front end.
So what was the compression?

 

Yeah, I think lifting the front end to get it started might have been due to a possibly unrelated flooding issue. I haven't tried lifting it to get it started lately. As of this morning it definitely won't start without restricting the airflow to the carb. I'll post the compression score when I hear back from the mechanic that has been helping me.

 

Compression is at 120.

 

Got it working. Recleaned the carb and the jets and adjusted the floats to let more fuel into the bowl. Works like a champ, fires right up, runs smooth as can be.

 

Now it is starting well, idling well, but giving it just a little gas consistently will cause it to go full speed. So only giving it 1/4 throttle will let it open up and go full speed. It isn't immediate, you have to keep on the throttle at that level and eventually something opens up and it will go full speed. I'm getting really frustrated with this machine.

 

Pipe plugged?

 

Came out today, little oil on the floor, gas has been spitting out of the carb overflow tube. Won't turn over, I'm guessing it is flooded. I'm going to swap out the petcock just incase that caused the flooding. The gas spitting out the overflow tube, I'm guessing that means the floats aren't adjusted right? I can't win with this thing. I'll check the exhaust while I'm at it. Thanks for the suggestion.

 

No adjustment on the floats if they are plastic. How did you adjust them? I would replace the needle assembly and soak that carb in cleaner.

 

It's in the carb still.
You can change the petcock but that isn't the real problem.
Like the fella above mentioned, most floats have a plastic tab. Some have a metal tab, neither is supposed to be adjusted.
Maybe you need a new carb. I get them off of ebay.