i have a 98 lt80 that has been giving me problems. i did a complete rebuild and it was my first 2 stroke ive rebuilt but i have rebuilt many four stroke quads and dirtbikes. i did a new bottem end bearings, seals, crank, a new top end cylinder and piston, new spark plug, boyesen power reeds, new starter, new carb with im sure a 90 main jet, dg pipe, uni air filter, got rid of the oil injection and im mixing redline 2 stroke mix 40:1 ratio. my problem is when i crank it over it spits and sputters and will not fire off. it will sometimes sound as if its building up compression in the motor then it pops really loud as if it is exploding inside the motor. im at a loss here. any help would be appriciated thanks kirk

 

Hi Kirk,
You got the timing back in the stock position, right?
Plug wet or dry.
If wet, apply full throttle till it starts.
If dry, stick 2 fingers in front of the carb to hand choke it.
Arrow on piston toward exhaust, right?

 

The piston is in right and the plug is wet and when I give it quarter throttle it almost fires off without the choke as soon as I turn the choke off I get nothing I'm thinking it may be the timing it's the only thing that would make sense to not allow it to fire off the right way.
Thanks kirk

 

"If wet, apply full throttle till it starts"
Did you try that?

 

i have done that and it just spits and sputters. im sure it is the timing thats making it not run. itll get to where it almost fires but it will not fire then sounds as if its backfiring back through the carb.
thanks kirk

 

Ok, you do know how and where to set the timing?

 

i know where it is and what it is but i didnt no there was a way to set it when i put it back on i just aligned the 3 screws in the center of the grooves on the magneto and tried to get it as close to where it was b4 as i could see where the screws set b4 on the magneto.

thanks kirk

 

At the 9 o'clock position there is a stamped line on the case and stator. Match the lines up.

 

i got the magneto in the right place and got it started yesterday. took it for a spin for about 5 mins with none of the covers on it just to make sure it ran. i hit a small puddle and it got the motor wet pretty good and instantly died out on me. i thought it was due to the magneto getting wet. i let it dry up over night and been messing with it off and on today and its seems as if the jetting isnt right on it. it has a uni filter boyesen reeds and dg exhaust. bought a 80 dollar carb off ebay and took out the jet that was in it which is a 92.5 main jet as its listed online and replaced it with a 90 main that came with the air filter and reeds kit. also the clip on the needle is 2nd spot from the top of the needle. im at 900 ft sea level. maybe u could point me in the direction for proper jetting on this thing.
thanks kirk

 

I'd run the stock jetting.
If you are doing this w/o the plastic, did you connect the ground wire?