Mates,
I give up! My sons 1990 LT80 won't start. We rode the several tanks of gas through it in July flawlessly. Left it on the trailer and took it back out 2 weeks later. Hard to start and wouldn’t hardley idle. Since then it won't start. I found the air cleaner had collapsed so I removed and thoroughly the carb and noticed the outer casing of the insulator between the carb and the cylinder was broken, and the O-ring was misshapen. Thinking I found the problem, I replaced the air cleaner, the insulator and o-ring. Unfortunately, it’s still dead, 80psi of compression, bright blue spark on a new plug and it won’t even cough on starter fluid! Before I take it to the shop, have I missed something obvious?
Thanks

 

Is there fuel dripping from the area where you exaust pipe connect to the motor? If so, you propably have the fuel selector in the prime location instead of on feeding it way tomuch fuel.... Your is a 1990 so I'm not sure if they have the same fuel set up.
jarsong

 

Jarson,
Thanks for the reply. The petcock is in the ON position not the PRIME position, and it is drawing enough vacuum to operate the automatic petcock properly while cranking endlessly on the starter.
Fitz

 

Hate to hear that your having problems. I don't think you have near enough compression to get that thing started. Chances are, it sucked in junk and had either scored the cylinder wall or broke the rings. Ours would start when cold with 90 lbs of compression, but not after it got hot. Sounds like it's time for a rebuild.

 

Definitely compression!
BTW: starting fluid should not be used on a 2 stroke. WD-40 in a spray can works well and is safe. [img]i/expressions/face-icon-small-wink.gif[/img]

 

Hey Jack, what is a good compression reading on the LT80. How much can be taken off of the head without having to redome, if I have already taken .030 off of the cylinder.
Thanks!

 

pops: I wouldnt shave the head any. The .030 should have done the trick.
150 pounds compression is good. On a stock motor 125 is good.

I should add: I usually tell ppl to take .030 off the head. I said not to cuz you did the cylinder.
Shaving the head OR cylinder .030 still allows for modifications later. No harm done. [img]i/expressions/face-icon-small-smile.gif[/img]

 

Any motor must have a minimum of 80lbs to even try and hit, but when it seems to get that low or close on a 2-cycle they just wont go. We run across this a lot in repair of weedeaters and chainsaws. Take a capful of motor oil and pour it into the cylinder then try and start it or take a compression reading immediately. If it starts or bumps up compression considerably then it needs a rebuild for sure.