'80 KZ750E cafe build

the dark blue 75 Z1 paint is my vote. always loved that color/stripe scheme. tail looks good on the 750.

Finally seeing the light at the end of the tunnel. Been a long project can't wait to ride.

Looks good,Im about to start fighting with my tail piece. Any advice?
What model/yeartail light are you using?

Tail piece is from a kz1000 77-up. The shop that was finishing up my project did it. (Starship Engineering, North Carolina US) they said it took some trimming but wasn't too bad to mount up to the kz750.

and the tail light?

Just gonna go with an aftermarket cateye tail light. I'll post a picture when it's mounted

Finally got the bike back from the shop. Rode it 3hrs home with no issues. Desperately needs a valve job. If anyone has a link to a thread on how to go about this I'd appreciate it. So all I need to do is the valve adjustment, build my seat and throw some paint on it and ill be good to go

motomadlin32 wrote: ...Desperately needs a valve job...all I need to do is the valve adjustment....

Valve clearance measurement is with thickness (feeler) gauges.

Valve adjustment is done by changing shims.

Valve job usually entails removing the valves from the engine head.

Would suggest first measuring the valve clearances (might already be within spec), and replacing shims where necessary to bring clearances within specs (follow instructions in the FSM regarding camshaft removal, correct assembly of cam chain, etc.).

May perform a poor-man's leak-down test to determine how well the valves are sealing when closed.

A leak down test injects air pressure through the spark plug hole to pressurize the combustion chamber.

Can perform a poor man's leak down test by introducing compressed air into a spark plug hole and listening to where it escapes from the combustion clamber. This may be done at TDC or any other cam positions where both valves are fully closed. Top dead center (TDC) is when the piston is at its highest position. An easy way to tell TDC is by alignment of the T mark with the case mark when viewed through the timing window.

May introduce a spurt of compressed air by using a rubber cone-tip blow gun (rubber air nozzle) held into the spark plug hole. And of course keep holding it in position to keep air from coming back out the spark plug hole while listening for escaping air at other places. The air compressor should not be running while listening because the noise will likely drown out any sound of escaping air. Or just use a portable compressed air tank.

Air heard escaping from exhaust port indicates exhaust valve not fully closing (perhaps too tight clearance or damaged valve or valve seat).

Air heard escaping from carb intake indicates intake valve not fully closing (perhaps too tight clearance or damaged valve or valve seat).

Air heard escaping from crankcase breather indicates loss of compression past rings into crankcase (perhaps worn piston rings or cylinders).

Air heard escaping from head gasket area indicates loss of compression past head gasket (perhaps due to a blown head gasket).

A leaking valve may sometimes be resolved by adjusting the clearance to within specs.

A leaking head gasket may sometimes be resolved by torquing the head fasteners when the engine is stone cold (such as after sitting overnight).


Hopefully, with valve clearances within specs, the leak-down test will indicate no leakage of compression past a closed valve.

Good Fortune!

Thank you for the reply, I had a shop do a leak down test and they said it had 8%/12%/8%/12% (as cyl 1/2/3/4) he told me that most of that would go away with the valve adjustment. He did a lot of work on the bike as far as tuning and jetting the carbs as the motor was. Runs really good but has difficulty idling and coming back down to idle speed after running. I've done a lot of reading and understand how to check the clearances but not sure what type of feeler guage to get. (Sizes?) I've got a new valve cover gasket on the way and want to get the valves specked out so I can get my shims on the way. Can't wait to get this thing on a real ride up to the mountains.

Oh and I also got new side covers to cover up the new wiring the shop did.

After clicking on the link below, scroll down to "The Bible" where there's a download for the Factory Service Manual.
mbsween.bike-night.com/kz750l3/index.html

The FSM includes information about the valves.

There should also be some threads here on KZr containing detailed guidance and photos.

Be extra careful when reassembling the camshafts and cam-chain, as a mistake can easily result in bent valves.

The racing idle is likely caused by an air leak, a primary suspect being old cracked carb holders.

Difficulty idling when warm is often caused by too tight valve clearances.

The carb tuning and jetting may be wasted efforts, as engine performance is seriously impacted by incorrect valve clearances and air leaks.

Good Fortune!

Checked my valve clearances today. All but one were less than .006. Should I find a smaller feeler gauge set amd
re- measure. Or are the clearance too little?