I have an 88 lt250, still to be done before spring is the mild rebuild.
The exaust valve is gummed up, so i Plan on pulling the head off to clean it out.
While off, possible a little clean up on the ports. No bore, no new piston, I know ill need new head gaskets , etc for re-assembly, but will i have to repeat the break in as if a complete top end rebuild?

Also, any tips on freeing up the exaust valve?

Other things,
the water pump seal, seems pretty straight forward, jus trickling coolant, so I will putll that apart as well

the output shaft seal, behind the front sproket. I replaced the seal last summer, once i swapped it, the thing was leaking worse than before i replaced it. Any tricks to that thing?

appreciate the help

 

Carb cleaner works nice on anything that is gummed up. It will clean up nicely.
No need for any special break-in. Warm it up and have fun.

 

There are many products out there that could clean this up.. without wrenching... Like Some additives to the fuel for internal motor cleaning. I dont know if the right thing to use in your case but I used some STP cleaner in my 400ex.. OMG WHAT A DIFFRENCE !!

just my 0.02 dude, that could save you lots of work and money

 

i tried carb cleaner into the exaust port, and tried working it free. I could feel some exterrmly filthy parts in there, but i was able to get some movement. I just dont think that I can get it free completely without popping the head off. If theres an easier way, Im all for it.

 

This is what I used...
STP cleaner

 

Does it run at all? If so I would heat it up fully and get some Seafoam. It is a liquid carbon remover. They sell it in most good auto stores. You SLOWLY let it get sucked into the back of the carb as you rev it just enough to keep it running. In an atv I'd try half a can. Then you shut it off and let it sit 5-10 minutes. Then restart and watch the smoke show. [img]i/expressions/face-icon-small-smile.gif[/img] They also sell it in a product called Deep Kreep that is an areosal version that is a little easier to use, but I don't think it is quite as strong. You can also run it in the gas to clean varnish for carbs, and injectors, and in the crankcase to remove sludge buildup in machines that haven't gotten regular maintence.