hi guys I am new to the LT80 I am working on this bike for a friend of mine. here's what I have. 120psi compression, great spark, the fuel is where I am getting confused? the shop manual my friend has is worthless! it doesn't show the vacuum lines and where they go. and it doesn't explain the prime setting on the fuel petcock or the start procedure. I have rebuilt the carb and cleaned it. the engine will crank over but will not fire, when I pull the spark plug it is completely soaked in fuel and fuel is dripping out of the front of the carb. if I put my hand in front of the carb it feels like it is sucking air in but it won't start. I can get the bike to sputter a little if I hold the throttle wide open. I'm pretty good at working on atv carbs and getting bikes to run but not sure how this one is suppose to work.
thanks
joe

 

The machine is flooding out. The float is sticking. You have been ethanol'd...LOL
Petcock: runs constant on prime. On is off til vac is made to open the lil diaphram.
The vac hose goes to the port closest to the motor on the carb.
Indeed hold that throttle wide open till it starts and cleans out.
The fix is a on/off valve close to the carb and shut it off when done riding. Running the fuel out of the carb will help too.
If you need more info, search a lil. Many petcock threads since ethanol.

 

thanks LT80! i was hoping you would chime in. The vac line on the petcock, where is it suppose to run to? (when i got the bike it was in many pieces) and the manual i have is worthless. it doesn't show you where the vac lines go. i know where the vac line is on the petcock just not sure where that line is suppose to go? i will pick up a in line fuel shut off and just run the bike on prime. right?
thanks
joe

 

Correct.

 

thanks, do I just plug the vac lines on the petcock and the carb?

 

That'll work.

 

I will give it a try.
thanks!

 

just wanted to finish this thread and give an update on what we found to be the problem. I hate when no one posts the outcome. so here it is. the bike had a busted reed valve. changed it out and now it runs great.
hope this may help someone in the future.
thanks for all the advise and ideas!
Joe