KZ900 opinions please

Yes I am thinking about taking the head off and having the local cycle shop lap the valves. I added oil to the lowest compression cylinder and tried again, no increase so maybe the head needs attention.

I'll have to look more closely at the plugs. I have several bikes that I'm constantly maintaining (H2, KH400, KZ900 and several other projects in the works) and I forget what the plugs looked like from which cylinder on which bike.

Colortune - by 3 adjustments do you mean pilot, mid range and mains? I only worked on the pilots and the air screw. Using the colortune did not seem as easy as I thought it would be. I'd turn the screw by 1/2 turns to look for changes in the flame color. I just bought the color tune based on your (OMR) comments about it in this forum, still learning.

The thing about taking the head off is if I go that far, why not replace the rings? Or should I just bore it out and then I know it will have more power? But then I might have to ship the block to the U.S. mainland for boring, plus cost of pistons and shipping. Life would be easier if we still had a shop on the island with a good reputation for boring motorcycle cylinders.

NO, all 3 adjustments/confirmations are regarding the slow jet turns...

Here you go....

Kapahulu wrote: The thing about taking the head off is if I go that far, why not replace the rings? Or should I just bore it out and then I know it will have more power? But then I might have to ship the block to the U.S. mainland for boring, plus cost of pistons and shipping. Life would be easier if we still had a shop on the island with a good reputation for boring motorcycle cylinders.

If the cylinder is within specs., just hone it and put some new rings. Won't necessary have any extra power just from the minimum overbore.

Hey Mike, hope you have had a Merry Christmas. You can always have the head done but a few of my friends went that route and later had to do a ring job. Hard to tell. If you do as I did and think 1075 then there are a lot of other things to take in to consideration. Being that guy who experienced what happens to stock timing chains when bigger cams are put in I guess I would leave well enough alone and keep her stock with a set of 29mm smoothbores or just go crazy like I did and rebuild engine completely, replacing all the worn parts with stuff from the APE catalog and getting crank indexed and welded, billet gears etc...it adds up quickly, especially when you completely tear it down and redo all the whole bike. Stock is nice with a little extra by means of intake and exhaust improvements added to a stock engine. You can always put a bigger sprocket on her which would give you a quicker feel off the line.
By the way, I am still waiting on just a few parts to finish my bike off. The bassani needs an adapter to work with my frame and within a month or two I will order the rest of the stuff plus have my tank set back from painter with the trick paint scheme going on. She is gonna be a LQQKER.

OMR, my colortune did not come with that chart. I'll see if I can print it out and review it.

Saxjonz, I look forward to seeing pics of your bike with the Bassani someday. In the last couple of years I have gone 2-stroke crazy. I have an H2, H1 with H2 motor, KH400, RD400 and RZ350. The H2 and KH400 are currently up and running. The others are projects that will keep me busy for a couple of years. And then I have the KZ900, the '78 KZ1000 and an '81 KZ1000. I might sell the '81 but I cringe at the thought of selling it to some guy who is going to hack off the tail, remove the front fender and make it a bobber or something like that.

OK, back to the KZ900. I finally got ahold of the shop in town that does cylinder boring and they WILL bore my KZ900 for about $200-240. I have a new idea of buying a set of used KZ1000 pistons for a low cost upgrade and getting a fresh set of rings. That plus getting the valves lapped and new valve seals, I figure will cost $600 -$750 total including gaskets and then hopefully I'll have a solid running bike.

Oh by the way I have a set of 29 smoothbores sitting around so I could put them on too.

Mike, sounds like you got it under control. I look forward to perhaps someday seeing those bikes in person. It's so little time so many things to do and see. I'm glad you have a collection of classic bikes. Some day they will be the talk of the town. Gotta love em.

I will totally buy the 81 off you man! Only a couple islands over too LOL I promise- no bobber! Cafe'd a bit perhaps. but no bobber

Cruising Ram I will PM you with my contact info.