Top End Rebuild Questions

[Jason350]

Ok guys like I've said before I am new to atv's. I bought my 94 warrior in Jan a few months ago for $800. The motor is all stock and runs great but burns a lot of oil, I mean this thing looks like I have a fog machine on the back of it. Haha. I bought my service manual yesterday, I know I need to pull the head off, my question is do I need to pull the head apart or pull it off all together? Any help would be appreciated, thanks.

 

[jgray44]

im pretty sure it will come off as one piece, if i remember right the only thing i had trouble with was the long head bolts that came out had to kinda push the motor around to get them out, unless theres a better way to do it.

 

[Jason350]

That's the answer I was lookin for cool, that will make it so much easier. Lol. Thank you

 

[bones]

1 )pull the cam gear off (try not the drop that timing chain)
2 )unbolt top motor mount
3 )unbolt header pipe
4 )unbolt carb boot from the head
5 )unbolt the head
6 )unbolt the jug for the lower motor cases

than you can work on your piston

 

[Jason350]

Thanks guys! Will I notice much of a difference in power with a .020 over bore?

 

[bones]

not much if any .....your only going for a 348cc to 353cc

 

[duneracerweston]

If u bump up compresion u will notice a performance increase

 

[hawkster0001]

but you will notice a little more power considering your s is now down on copmression and burning oil, so you will notice a little bit over what you already have.

 

[MotoArts]

Just did mine. The compression rings were fine, but the oil rings had no tension; oil dripped out the tailpipe like a 2 stroke, but it ran great. Standard bore was near perfect.

That said, I'd definitely recommend disassembling the head as well while it's off. Mine was run without/low on oil by a previous owner, causing wear on all "sliding" contact points. Rocker shafts are a bit of a PITA to get out and in. Cam pops out with a slide hammer pretty easily. The big cam bearing and stock valves can be found very cheap on Ebay. If your cam is toast, there's a nice complete kit available to do it all. Mine needed a valve job, too. The factory seat cut on the intake side was horrible, and the exhaust seat was pitted (normal from use). Deck surface on the head from the factory wasn't pretty, either. Squared it up with a sheet of 220, 400 then 600 sandpaper on a glass table in about 45 minutes.

Better safe than sorry, it's cheap insurance.

 

[Jason350]

I'm goin with the wiesco 10.25:1 piston.