Air passages from head to reed valve assembly

Greetings all. I have just removed the head from my 1982 GPZ750 with 87,000 miles for its first ever top end rebuild. I noticed the passages from the head to the reed valve assembly is clogged on both sides. I can't tell if this is some kind of rubber plug that has degraded or just cooked and clogged oil. If anyone knows whether this should be cleaned up please let me know. All the best, Mark

It's most likely carbon build-up, if you are adamant about getting the fresh air system working clean them out, if not it really wont affect anything, many people just block them off

Welcome. Looks like a head refresh is timely. Pics more pics.
Steve

I'd be more worried about the amount of black carbon build up overall. It looks like either someone didn't change the oil very often, or the engine is worn putting a lot of deposits in the oil, or both..

It's carbon build up. Perfectly normal for a bike with that many miles on it.

When rebuilding my 750 I tapped the holes and installed metal plugs. If you just want to restore the bike back to stock just clean out the carbon during the head refurbishment process. No big deal.

Nessism wrote: It's carbon build up. Perfectly normal for a bike with that many miles on it.

When rebuilding my 750 I tapped the holes and installed metal plugs. If you just want to restore the bike back to stock just clean out the carbon during the head refurbishment process. No big deal.

Oops I missed the 87k miles in the original post, yes that would be normal, particularly given some wear starts to be inevitable adding to the carbon build up. It's impressive the miles these Kawasaki's are capable of when only a few years before many other bikes needed attention by 12k miles.