I have a 96 Scrambler 400 4x4 2 stroke. I am getting coolant in the counterbalance oil, I have been told that if the headgasket is leaking, and coolant is getting in, then the sparkplug will be clean, and that it will run like crap, and if enough coolant is getting in then it won't run at all, But my atv runs great, the sparkplug is not clean. Is there any other way that coolant can get into the oil? And how bad is this on my atv?

 

It is the water pump leaking in. It will cause the counter balance bearing to rust an then break apart an cause alot of damage to the bottom end. I use a syntetic gear oil in mine.

 

just the gasket needs to be changed or the entire waterpump?

 

nothing wrong with head gasket it. It is the water pump it has happend alot to the 400 motors. They seem to get a small leak in to the counter balance cause the pumpo is ran by the counter balance.

 

thanks for your help, now I need to find a waterpump..

 

A new waterpump/balancershaft is about $380.

One can be rebuilt for $75.
Seals will cost about $18
A gasket about $8
You can take it apart and fix it at home for around $100 or so .

Rick

There is a special socket you really ought to have too .

 

Thanks for the infor rick.... which socket is it that I need? and where can I get it?

 

I believe he is referring to the socket which is used to remove the reverse-threaded nut behind the counterbalancer. Most people use a hammer and punch to remove the nut. I used a 6" long 3/8" socket extension as a punch and the nut came loose fine. Remember, lefty tighty, righty loosey.