leaky atc250r head.......

[atc4me]

hello everybody, im new to the site and i totally dig all the threewheel nutz!!! ive always been a fan of the atc 250r and finally got one that needed a rebuild/restoration ive totally stripped it down and working on putting it back together, i got the engine back together and fired it up to make sure that it ran after being completly apart. there was no coolant in the motor and it only ran for about 45-60 seconds(it sounded BITCHEN) .i finished everything else,tires plastic,etc and the last thing to do was put the coolant in. when i did it ran out around the head bolts and between the head and the cylinder.i took the head off and put thread sealent on the head studs (i didnt do that originally and thought that was the problem!) i put a straight edge on the head and it looked o.k. in some spots and questionable in others, my straight edge is questionable.i put some 600 grit on my flat bench and worked the head on it for untill everything looked shiny and clean and tried it again, same head gasket and still leaking but not near as bad.do i need to have my head milled, and maybe a new head gasket to make this stop leaking? can you mill the head ?thanks for any advice. ive never done a rebuild on a bike before so any advice is greatly appreciated,ive done a hundred small block chevys but im lost on this 250. p.s. i love this site!!!!!!!!

[atc4me]

one last thing, the manual i have says to torque the head bolts to 21 ft/lbs is that correct?

[250r'en +TCB]

If you have a granit countertop, or polished marble slab, put the head on that and see if it jiggles at all. Those are TRUE flat surfaces.
Go and get some copper spray. Spray BOTH sides of the head gasket completely and the studs (be careul not to get any in the cylinder obviously). I had the same EXACT proublem about a week ago and this has worked for me. And i just got finished from riding it ALLLLLLLLL day. wOOt!!!
let us know if it works, it should.....
EDIT: I forgot to mention, make sure the head gasket is good to begin with. 250's are known to blow them.......If you do have to get a new one spray the copper on it just the same.....

[250rAL]

You might need to have the cylinder decked. Same process as milling the head.

[atc4me]

thanks for the info. , i have the head at the machine shop now so i will try the new gasket,copper coat and milling to see if that fixes the problem. i dont want to tear the cylinder off just yet. hopefully this fixes the problem. does anybody know what the correct torque numbers are for the head? thanks

[BigGreenMachine]

Remember to retorque the head bolts after the first warmup/cool down sequence. Let the motor cool completely before doing so.

[250rAL]

17-21 ft lbs.

[atc4me]

thanks everybody for the info. i had the head milled(my machinist found a bad spot ), Quality Outboard Boring and Sleeving, Dale at 425-741-1125 in mukilteo,washington the guy is a perfectionist !!!! copper coated the gasket and mating surfaces and a thread sealant on the threads. its holding water for now. my first test ride will be tomorrow and hopefully everything is going to be o.k.

[BigGreenMachine]

Awsome to hear, hope you have a good ride.

[KASEY]

thread sealant on the threads

THIS IS TOTALLY WRONG,,,,if your gasket is leaking to the studs you should fix THAT problem,,, not seal the water into the studs,,, wonder why you can never get the RUSTED studs out??????????

[crackshot]

THIS IS TOTALLY WRONG,,,,if your gasket is leaking to the studs you should fix THAT problem,,, not seal the water into the studs,,, wonder why you can never get the RUSTED studs out??????????

Not to mention throwing torque settings off.