Jump to content

rm80 burnt piston possible cooling problem

Recommended Posts

Hi guys i have a 1990 rm80 it has about 12 1/2 hours on a new piston and rings...kind of new to this but to me it looks like it got too hot the bike never seemed to run hot always checked the temp seemed ok had been noticing alittle coolant disappearing after every ride but never thought much of it just refilled it.. so after taking the piston out i checked the gear oil and it was not good milky white so i know coolant is getting in there somehow would that have made the bike run hot and where should i start iam thinking water pump seal..dont want to buy new piston and rings and have the same problem again in a couple hours of riding thanks

any help greatly appreciated 

DSCN1585.JPG

DSCN1588.JPG

Share this post


Link to post
Share on other sites

Head gasket leaking its burning antifreeze why all the black.  But looking like something coming apartin there buddy.  Time for a bottom end 

Share this post


Link to post
Share on other sites

found coolant in the gear case and coolant was disappearing from the radiator i think the water pump seal is bad just put a new head gasket in with the top end the bottom end seems great

what do you think?

Share this post


Link to post
Share on other sites

The problem could be a number of things....  Easy things first, make sure that there is the proper torque specs on the cylinder and head bolts, if those are loose, you could easily have coolant get into the cylinder.  If the bike runs, fire it up and smell the exhaust, if it smells like maple syrup, that means coolant is getting into the combustion chamber from the top of the head (replace head gasket with proper torque specs).  If it doesn't smell like maple syrup then coolant could be leaking straight into your crankcase from the base gasket.  Take caution because antifreeze will easily wash away oil from your bearings, crank and rod.  My recommendation would be to change the base and head gaskets using the proper torque specs and also make sure you're using the proper gas/oil mix, and running the correct plug (heat range).  Hope this works out for you

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:


×