Z650 / GPZ / ZR 810 hybrid rebuild

I have an issue with an 810 wiseco engine made up from all different models and am trying to solve a compression and mixture problem. I,m rebuilding after 20K and 12 years of forging her.
It's running excessively lean and hot on several test runs even after upping the main jet from 115 to 125. With a light hone and new rings she has 140 - 150 psi. Idles and revs good when it's cold and just started.
I'm thinking maybe bigger inlet valve would help, so looking at a eBay supplier " getor" they show the inlet valves as 34 x 7 x 92.8 to fit all the z650s and 750 models except the GPZ750ZX unit rack
Do they have bigger valves? If not would it help to fit some? If so what size?

I run the same set up. 115 main in my rs 34 mm.runs Great. Check your carbs out might be plugged up.don't bother with bigger intake valves. Not needed.

Jimmybon:

I see youre using Mikuni RS34 with a stock airbox and rubber inlet ducts. Did you have to modified the airbox or was it just plug&play?

Thanks Undiablo, it's a GPZ750 R 82 air box with a K& N filter. It's all about this bike looking standardish. It's fits straight to the RS34's. I prefer the box as I do go for long rides including dirt here in Oz
I,m going to try a colder plug and see how that goes

I stripped the carbies and clean every jet with petrol and air. I lifted the needle as high as goes, and am using 20 pilots