Sadly a mouse made its nest in my kids LT80 air filter box.
Started investigating a no start and found air filter chewed up and packed with grass. All sucked right through the carb and into the reeds. Cleaned that mess all out.
Compression is 90lbs cold, 150 cold and wet with 15/40 in the cylinder.
It fire right up and runs with a few cc of 15/40 to prime the cylinder. After a short ride I have 75lbs hot. Seems to run not to bad once I get it started but I not going to be priming it with oil every time.
I'm looking at the $55 cylinder kits on ebay and a new air filter of course for a stock type. Anything else I need? Hope to have it up by Sat for a ride.
I'm a diesel tech but still welcome any pointers.
I have the oem manual.
I read the ports are not chamfered on these cylinders (Thanks Jack) but anything else?
Anyone got some hours on one of these cylinder kits to see how they stand up?

 

Might lightly chamfer ports to avoid a possible ring snag, I used the original head gasket didn't like the one supplied. Clean carbon out of head dome,arrow on piston toward exhaust. Lube ( 2 stroke oil) all pivot points piston pin holes ,pin, bearing, cylinder wall, a few drops down crank bearing holes and few drops on connecting rod bearing. I've got about 15 hrs on one 7hrs on another haven't done compression check lately, but 15 hr topend was same compression (124 psi) after break-in and 9hrs, with no problems so far.

 

Ok thanks for the pointers.
I meant to say stock type rebuild in 1st post.

I guess there was no problem reusing the head gasket? Must be the soft metal variety?
Did you have to remove the 4 main cylinder studs to be able to get the jug out? I see they supply new ones so I'm thinking yes. Also were you able to leave the gas tank and fenders on?
Thanks
Ken

 

Studs don't have to come out, but it makes piston install easier. One company thought their package looked better with the studs so everybody started including in theirs. Front fender might could be loosened up and slid forward, I took mine off,but tank will need to come off to lift cylinder off the studs and get the air ducting off. When installing piston put one of the cirlips in while out of bike and cram a rag around the rod to cover falling in the bottom end while installing the other circlip.

 

Best not to remove the studs IMO.
Fenders and fuel tank doesn't have to be loosened/removed.
You will have to take the coil/CDI off so the jug will come off.

Listen to him about that rag!! Cir clip in the bottom end sucks.

 

Well parts are in so I pulled it down this am. One scratch on the intake side of the piston otherwise the piston and bore look good. Except the ring ridge (a few thou) and the .090 gap in the top ring.

New rings have a .005 gap in the new bore. Need to check that spec, do some chamfering and cean things up. Head is almost clean, had very little carbon on it. Exhaust and piston look like they have been running the right temp.
I'll check in later.

 

1 hour on it now and running great. 130lb compression. I took a steel screen out of the air filter from my ram pickup and molded it around the air intake under the fuel tank. That little mouse won't be getting in there again.
They should include the exhaust studs. Hard a hard time getting them out until I heated up the jug a with the torch.
Also this had silicone on the base gasket, would that indicate it had been apart before??

 

Also this had silicone on the base gasket, would that indicate it had been apart before??
Yes.
Glad it's working out.

 

Are you interested in the old cylinder Jack or do you have plenty?
It looks as though it has never been bored and I think a .010 cut would clean it up.

 

Might be.. email me.