I recently purchased a lt80 that looked really good for it's age and I could hear run. The guy showed me on a compression gauge that it only gad 66psi. But hey it did run with a little starting fluid. When I tore it down the jug/cylinder was junk and piston pitted and broken. The head doesn't seem to be damaged. I tore the complete engine down in search for pieces only found one. I think this guy had tore it down part way and gave up and luckily for him it ran enough to sell easily. I feel I should replace the crank bearings and seals, I know it needs a top end. Has anyone had luck with the aftermarket cylinder kits? I noticed this 80 has an aftermarket carb and wonderd if it was ment for oil injection and maybe thats how it melted down. Any info would be great I have pics of the piston and cylinder in my profile.

 

I feel the wore piston is normal (not a oil problem). I see many like that.
The cheapo cylinder kits: I have run them. The ports usually need a lil work and the ports chamfered.
Your cylinder can be bored if you don't want to go china. It's on stock bore.
What kind of carb is it (pic maybe)?
Bearings/seals: you have split cases before?

 

 

I have never split the case on one of these before. With the suzuki manual and a little fab work I managed to split this one rather quickly and easily. I don't have a inside micrometer or I would check the damage to the cylinder. How far over can these go? I dont think I have ever seen a cylinder this bad but I generally only rebuild small block chevys. I'm on a budget but want it right even if it takes until Christmas to finish. My son is seven and a little guy for 7 so I think this will last him for a while.

 

That's the DG 20mm carb.
Cylinders can be bored till 52mm (3rd over). Good chance 1st overbore (.05mm) would clean it up.
You can get the China special, I'm sure it'd last with the above mentioned tweeks.
I'm more worried about you getting the cases together with a straight crank. Maybe research, I've explained it plenty.
And yes, that LT80 will last him a good many years.

 

So case alignment can be tricky I take it. I will do my homework on that. I don't have it in front of me at the moment but I was thinking it had alignment dowels in the case. I will see if I can get the cylinder measured out tomorrow.

 

Would you stick with this carb or ebay and rebuild a stock? Looks as if was ment for this bike.

 

That carb will be fine. Keep a good filter on it.
Yes, the cases are doweled. Trick is to get the bearings to go onto the crank freely (no bind).

BTW, Nice job cleaning!

 

I looked up Rockbridge.
Bring me coneys and I'll do it for you.

 

Other than the crank I haven't cleaned much. I plan on taking cases to work and cleaning in our heated solvent tank. I'm kinda questioning the trans/output assembly though. I prefer everything spotless before assembly. With the silver and aluminum debris I found when I pulled the jug off I expected much worse below. I probably could had turned upsidedown and brake cleaned it out and put new seals in it and been good.