Anyone have problem with exaust valve wearing out on a 97 king quad 300.

 

hey and welcome to the forum.

are you running lean? that can certainly burn an exhaust valve. also, are you running open exhaust?

 

If anything its a little rich, exaust is original.
The valve looks worn versus burnt

 

What does the intake valve look like?

I've replaced a lot of intake valves, but hardly ever an exhaust valve. The intakes wear from a crappy air filter letting dirt in.

 

Intake valve is good and original I have had to replace the exaust valve 3 time. Where it come in contact to the seat is worn pretty thin.

 

What condition is the valve stem guide? Is some kind of abrasive particulate in your exhaust? Could the seat and valve angles be different??? Is the valve lash set properly? Could the valve be getting so hot, the hardness goes away?

A typical intake valve:

 

I've seen that before a couple times on my 91 LT-4WD

 

This picture is what my exaust valve looks like and maybe the valve is getting to hot what would cause that and how to correct it.

 

If the valve is getting too hot, maybe the lash is too tight and the valve isn't closing all the way. Once the hardness goes off the surface, it doesn't take much to wear it down like that.

 

What about valve float?