Top end rebuild problems :( please help!
Hello there guys, my 1997 dt125 started dying the other day... (started loosing compression, wouldn't kick start, managed to get it bump started.) got halfway to work and it really started dying and went limp if that makes sense.) I got to work got through the day came out, after a few hard attempts i managed to get it bump started again and limped it home. (I know this isn't the best, didn't have no other choice ) got the head off, fried piston rings with minor scoring on the edge of the exhaust port and piston, managed to get rid of the score on the barrel as it was right on the edge of the exhaust bridge, (used wet and dry) got hold of brand new gaskets (hendler brand, made in italy) and piston kit and attempted my first rebuild. cleaned the barrel and where the gaskets join meticulously and attempted to put it all back together torqing everything up to the correct specs and lubing all the parts with 2 stroke after cleaning a load of carbon off the power valves, barrel and head. got some coolant in her and a fresh tank of fuel with castrol power1 racing 2 stroke at around 35:1 (usually run 30:1 but read that it will want it more rich for rebuild) got it all together and tried kicking her up, i now have water seeping from the top head gasket. i have purchased some instant gasket and im going to strip it again shortly. just wondered if you guys had any advice before i go at this again, its my first rebuild on the bike and i have tried my hardest to get it right... there is no leaking from the bottom gasket on the barrel just seeping from the top head gasket, and when you try kick it over there is water coming from near under the swing arm (which i've also read is head gasket failure). should i strip it clean it out again and apply instant gasket to the failed head gasket? thanks in advance for any advice on this guys....
Did you use a torque wrench and tighten the head nuts diagonally?...
Challenger last edited by
@westy7070 I always use a thin layer of Loctite 5923 on the metal head gaskets. Never failed me. Many people use Reinzosil except the Loctite as it comes in smaller packages and should work as good.
I’ve always used semi hardening paste on head gaskets, though only on 4/‘s. Hermatite red was my favourite. I’d never use silicone if possible...
The whole point (I think) of using an annealed ally/copper gasket is they are soft and conform to the needs of the join. Did you clean the barrel top and head surfaces properly?...
Calum last edited by
Never needed any form of liquid gasket on the head. Just use the genuine gasket alone is good enough.
I like to skim the head and barrel if it's overheated but not necessary.
I agree. 2/‘s (2 strokes, for the uninitiated ) don’t usually need sealant. Some old ones don’t even have gaskets. Given, those weren’t liquid cooled.
4/‘s (4 strokes) are the only ones I’ve ever used sealant on, and then only because I’ve reused the gasket. They usually have a silver film surface on them in my experience. I’m guessing that the black ‘paint’ on 2/ gaskets is something similar? A dry sealant?...
Someone with more knowledge (& > sober) than me will hopefully elaborate ... ...
If an engine overheats I’d definitely skim the head at least. Or check it! you can’t be too careful...
Sorry for the mega late reply on this lads, sacrificed internet for the rebuild at the time and just wanted to say (now i remembered :P) Thanks so much for all your help. got it sorted with the loctite in the end and it all worked out! really grateful for the replies. will post some bike porn soon and start getting active!