Damage inside head, need input.

[Dangeresque]

I'm currently tearing down a 1972 XS2 that had sat in the weather for 30 years.

Upon cleaning the gunk out of the head to see if its usable i noticed there some damage behind the intake valve, the valve seat looks fine, looks like something got banged around up there a little.

It's cleaning up pretty well so far with little to no pitting, just want to know if its a bad idea to reuse it.

 

[5twins]

Oh, that's not damage, lol, that's simply Yamaha's idea of a port job. Yes, the ports as they come from the factory look something like a Lunar landscape, lol. You can fix it (and many of us do) by smoothing it out with a Dremel.

Here's a port from one I worked on last summer - before I had my way with it .....

Look familiar? What you're seeing is the machining marks left behind after the valve seat install. Yamaha never bothered to clean them up. Besides those, you're also going to find all sorts of rough castings deeper in the port .....

A little time spent with a Dremel can remedy all that .....

 

[Dangeresque]

Fantastic! As i just cleaned out 2 more valve seats i saw more of this magic. Appreciate the detailed reply!