GPZ750 - how tight should the cam chain be?

I wouldn't do that on something with aftermarket cams, non standard timing and or a skimmed head. Just the motor had been turned quite a few times by hand following a valve clearance job, and the top run indent is minimal on that. Following that i did a compression test and a wet test so no problems there. (1) Done about six or seven hundred miles and it runs very nice.

I had a 550 that was a tooth out on the valve timing, sounds unbeleivable to me but there was no interference.

Cranking that over at 200 rpm after turning it over by hand I'll accept the risk, I'm more concerned about valve bounce on the redline - not apparently an issue on that standard motor. Unlike the tuned 550 the 750 seems to run out of steam at the redline, but has such nice tourque I don't really need it. Reminds me a bit of my z1100R.


(1) one pot was badly down, before the wet test as mentioned on the kz750 smoke thread. I suspect gummed rings, the bike has barely done a 1000 miles in the last decade. It seems to be running really well now, will redo the compression test soon .

Hmmmm. not the best weekend...firstly when I was lifting the bike onto the paddock stand it slipped off one of the rollers and fell. I lost my balance and was unable to hold it upright...couldn't believe it. First time it's ever happened in 40 years...I have to realise I am not as sharp as I used to be...no major damage just broken ignition cover and brake lever...and a few scratches...very sad.

Anyway...I set it up again then went and made another coffee...I hooked up a compression test gauge and discovered why it was running so rough - almost zero compression on #2.

I'll take the head off tonight and see what's going on.
I'm thinking bent valves - but why only that cylinder
Stuck valves on that cylinder
Stuck rings. I did have trouble with my home made ring compressor when I was putting her back together. Maybe I damaged the rings although all the other cylinders had reasonable compression given the age of the engine...it's not blowing smoke and the plug colour was good when I checked after a short ride.

I didn't think stuck rings could cause almost zero compression, so I haven't bothered doing a wet test...do you think it would be worth while or put my money on valvle problems.

Ps. Just realised that I set cam to z7ex instead of z6ex... Will that make big difference? Cheers Brian

Check the valve clearance on #2 cyl before taking the head off ..... if its a bent valve you should have about double or triple the clearance as you had before.