1981 Kz650 head questions

All looks pretty normal to me, burning hydrocarbons gives heat, Co2 .water and a load of other stuff, some of that staying in the combustion chambers and manifolds.

I'd be more interested in a side pic of the pistons, is there much evidence of oil burning below the rings - or maybe looking at the colour of the exhaust valves and plugs.

Carb cleaner is good for cleaning this, and mayve a wooden (no scratch) scraper. Note recent safey warning posted here on carb cleaner and eye protection, I always knew it was nasty stuff.

After reading this I'll say this Just find a ZX750A1/A2 motor and and be done.
Bone stock it's like 25 hp stronger and with some goodie's my 810 motor's making mid 90's.
with stock ZX750A1 cam's.

zukdave wrote: After reading this I'll say this Just find a ZX750A1/A2 motor and and be done.
Bone stock it's like 25 hp stronger and with some goodie's my 810 motor's making mid 90's.
with stock ZX750A1 cam's.

If my head works with the 750 block and the carbs will work with a stage 3 then I am only out the $75 for the block and pistons. Of course I need a seal kit. I got a new cam chain and guides already (actually bought them in 2009). And I was planning in doing some head work and cleanup myself. An engine on ebay is $499-$599 + freight. I am looking for a good running bike with some pick up but I don't need to go crazy. Maybe if I find a cheap pair of 750 cams I can throw them in as well....

Side of the piston looks fine to me.

My pistons after 30k miles. You're looking fine.

Yeah. I didn't think there was an issue. I need a new cam chain and guides and thought I would do the rest while it's all torn down. I think I caused the cam chain issue many years ago by tightening a manual chain tensioner to much. There are groves in the guides and I had a lot of noise after that. The chain actually looks fine but I decided to tear it down and replace the seals, chain, and guides. Prior to me my best friends dad bought this bike new. He rode it to work all the time for many years and kept good care of it. As a kid growing up I helped with many oil changes.

When I say no issue I was not sure on the build up in the head. I knew the Pistons and engine were good though.

I don't know if you've had any luck with splitting the head yet, but make sure you check the valve faces to see if they're worn. Mine were worn so badly that there were grooves in them, not seating properly/at all. The valves had to he refaced and then the head had to be shimmed. Just something to keep in mind

I have not split the head yet. I would assume that just means pulling the valves. Sorry not up to all the lingo yet. I was going to see if this was possible with a big c clamp I have I guess some people are successful. If they look OK I will probably just clean everything up. I saw somewhere you can get the 750 intake valves and use them on the 650 head. I will look into that if valves are needed.

Be careful. The KZ650 intake valves are a different part number than those used on the KZ750. Ed

I thought I saw someone that did the 750 block with the 650 head.

www.kzrider.com/forum/2-engine/559505-kz...l=component&type=raw

Looks like it was a success. I will upload a bunch of photos of my 750 block and pistons when it comes. I want to see if there appears to be any issues before moving forward. The block I purchased is from a 1983 Kawasaki KZ750N. The only thing I will have to figure out if its in good shape is how to remove the paint.

No eBay APP ID and/or Cert ID defined in Kunena configuration the listing has some photos. Everything looks pretty good to me...