LT80 Runs like it has an air leak

[moto33]

Hi, I've been reading alot of posts about lt80s with the same issue as mine. They all say to check the pilot, and compression. Well I replaced every thing in the carb with the rebuild kit and did the top end. Compression is great. It only runs with the choke on and runs like it is going to sieze up for a 2nd time. Idles way up then drops off and bogs. What are the chances a crank seal is bad? I'm going to take the carb apart for the tenth time and check but i'm not to optomistic. What ever is going on caused the motor to sieze once. Any ideas? Thanks for your time.

[TRX450RACER174]

Well the motor seizing is from no lubrication or lack of lubrication are you running the injector pump or premix? imo the injector pump is junk my 05 ran the same way only with the choke on i took the injection pump off and ran pre-mix problem solved mine was loading up with oil, could be a bad crank seal what about the reed cage does it look good ? LT80 might chime in he is a wizard on these motors and can point you in the right direction.

[moto33]

Thanks, I am still running the injector but I'm pretty sure it's working because I can see and smell the premix. How hard is it to remove the injector? Do you have to remove the whole side case? This is my last 2 stroke since I got a bad *** trx450 and sold the LT500. I would like to use one gas can if possible. This thing is just a pit bike. Thanks in advance for any input.

[moto33]

Oh yeah, reeds look good. New gas. It got pretty hot when the piston let go. I hope I don't have to do the crank seals. I'm trying to do a leak down test but my kit doesn't match up with the bolt on style carb.

[LT80]

It sure sounds like it's sucking air. That would lean it out and squeak a cylinder.
FYI: crank seals are like 5 bucks each and are not hard to replace.

[moto33]

Thanks, I think I'll go in that direction.