top end rebuild

[jdager]

Hi all,
first of all, thanks for all your help so far. I am thinking about picking up a cheap 98 kx 125 that seems to be in great shape with lots of extras like exhaust, handle bars, bark busters, etc, but the engine is siezed. the person says that the piston ring is seized. I was wondering first of all, what kind of price range I can expect to spend on getting it fixed? I know its hard to say without getting in there and taking a look at it but a general idea would be great. also, does anyone have some good links on how to tear it apart and get everything replaced? I have a friend that is gonna help me do it but I would like to read up on it before we tear into it. I am very novice when it comes to engines so explanations and pictures would be awesome. thanks again,
Jim

 

[_JOE_]

Generally 500-1000 bucks. Depends on wether or not the crank is ok. If just the top end is toast, you may as well send it to Eric and have it punched out to a 144. If it siezed it will likely need replated anyway and thats the majority of the price difference to go to 144. I think the whole deal with top end kit is under 500.

 

[yamarider88]

$120 if it's just piston and rings wrist pin and needle bearing and necessary gaskets. $300-$500 if it needs re-nikkasiled. i think i paid around $400 over all when my 250 blew up on the exhaust bridge at the dunes and had to have it nikkasiled.

 

[jdager]

thanks for the replies, what should I look for when tearing it down and what should I plan of replacing for sure? also, I have a 97 kx125 that I am planing on doing a top end on as preventative maintance, runs good, but what all needs to be replaced when doing a normal top end? piston, rings, top end gasket, any thing else? anyone know where to download a service manual for either of these bikes?
thanks

 

[yamarider88]

make sure you do the needle bearing the wrist pin goes into they can explode if they wear to much.