76 KZ900 Continued Engine Problems - The Saga Continues

And just remember Chris...You're checking valve clearances with a COLD engine...not warm...has to be 100% cooled off to get proper readings,Bud.

I finally got back to the KZ recently and rechecked my valve clearances COLD... Everything was within spec just as I had hoped.

So I've installed carbs from WG, new coils, new dyna ignition, new plug wires. Timed the bike and even tried to advance the ignition... Same problem still exists.

I get lots of popping and backfire and still have the 'sucking sound' at 4.5k RPM when accelerating.

The only thing I haven't done is replace my spark plugs since I put on the new ignition. I will go ahead and do that.

I am starting to think as I have all along.. its the carbs... If they are not synced to my bike, could this cause these problems?

HELP! A year later and about 1200$ it still doesnt run right.

For consideration if not already done --

Would double-check ignition timing by using a strobe light. And confirm operation of the advancer unit. Maybe the advancer is sticking or for some reason not freely advancing (perhaps just needs cleaning and lubing). Thinking this might explain performance being okay during WFO acceleration but otherwise unacceptable.

Also assure integrity of metal fitting onto plug wires where plug wires insert into coils. And use dielectric grease here and on plug caps.

Is battery fully charged and well-grounded to frame?
Should be reading 14-15 volts at 4000 rpm?

Keep the faith.

Timing was timed using a strobe light. Timed at the 'F' Mark at idle and checked the advancement per dynas and this sites instructions. The wires, coils, everything are brand new from z1.. so I dont suspect anything there, had the problem before i replaced ALL of the electronics and still have it... so I am ruling that out.

I can check the battery voltage.. Check it at the battery or where?

yeah just check it at the battery

yeah just check it at the battery

yeah just check it at the battery

Make sure you don't have a main jet loose or missing on the carbs. Don't ask me why.

Also, if you still run the stock air box........remove the a/c lid or muffler (if equipped). My 29's refused to run with the stock air box. Do this for testing only.

Sometimes air restriction can mimick the same problems.

Post edited by: arai60, at: 2007/06/16 21:14

Post edited by: arai60, at: 2007/06/16 21:28

Chris, I would imagine you checked but incase Make sure the cams are in time. If WG redid your carbs then I don't see that being a problem. It sounds to me like a timing Issue. What does it do on a compression test? What kinda carbs do you have on it and does it have any motor work done? While you have the valve cover off take a look at the cam chain idler on the top of the motor as it looks like the stock one. I have seen the rubber harden, split, and then idler comes apart. If it looks at all questoinable I would replace it as there about 85-100 for a stock one or one from schnitz. Good luck

I finally got the bike running perfectly.... And I was right.. the carbs from wired george were all f'ed up. One of the floats was not the same as the other 3 and the float level was off on one really bad.. barely pushing any fuel into the bowl. I also raise the needles one notched and cleaned them all up. Now it runs perfect.

Glad to hear You got it all figured out Chris...right on Bud.

Do as BSKZ650 said and sync those carbs!