80 liquifire problems

[Kmich]

So I bought a liquifire this year! My dream sled and I love it. However I was not to happy with the machine and myself as I was left stranded yesterday. I decided to clean the carbs up because the sled seemed to bog when you gave it more throttle. So I cleaned them up and all is good seemed to run much better. So I left town and got to a field opened it wide open and things seemed to be goo until the top end seemed to die off. So I let off the throttle for a bit then tried again this time it made a little scweel sound and stalled. Opened the goops looked around and nothing. Pulled the cord and all was good. It sputtered but started. Off I went again. Tried to open it up again and the same thing. Scweek and die. This time it wouldn’t start, fire once maybe but would not start. Pulled it home now and I’m not sure where to start. Any ideas guys? Cdi box? Fuel pump? Coil? Or am I looking at crank seals? If so how do I make sure how can I make sure it’s a crank seal issue?

[Kmich]

Oh and I also forgot to mention one of my spark plugs seems to be loosing the ceramic around the electrode inside the plug. First I thought it was a faulty plug but now the same thing on the same cylinder

[JDGuy]

Detonation can cause the ceramic to crack/chip at the electrode. Detonation is not the same as preignition. The ceramic can also get cracked setting the plug gap if it is not done properly. Best way to evaluate engine sealing is a pressure test, it is described in the service manual with the leak down specifications.

[AirborneX4Special]

I'd be afraid that you've leaned it out on one side and melted down. How long since crank seals were done? Carbs need to be squeaky clean and no air leaks around the flanges.

[Kmich]

Yup looks that way airborne. Did a compression test tonight and I got 50 on one side and 125 on the other. Looks like it’s time for an overhaul. Anyone know if you can oversize the cylinders, Incase they are scored?

[AirborneX4Special]

Tear it down and see what you have. 50 psi sounds bad for both pieces but you don't know until you know.