z650 with gpz750 motor carb problems - help needed

[stevew65]

Hi all, hoping someone may know someone near swindon that is good with carburettors. I bought a gpz 750 motor without carbs, fitted my z650 carbs just to get out on the road, short trips across town. She ran okay but had a bit of hesitation though traffic. In the meantime searched hi and low for a set of gpz 750 carbs thinking that this would be the solution. It wasn't had all sorts of problems not wanting to rev up, so stripped the carbs again and cleaned again, got her to rev but still not right, misfiring, pop bang....

So bought another set of carbs thinking maybe the first lot were not good, cheaper than a rebuild kit also. So fitted these but it will rev up, but now 1 and 2 are not firing, swopped leads 1 and 4 still same prob, swopped plugs the problem still staying with pot 1 and 2, these have a spark and there is fuel in the rubbers but the plugs don't seem that wet, and still misfiring popping and banging. Okay my next job is to strip these carbs and check clean etc, but these came off of a running bike so thought it would at least be closer to being right.

really starting to get me down to the point where I have thought of rebuilding the 650 motor...

cheers steve

[Pigford]

Are rubber manifolds OK Run bike & spray WD40 on them to see if revs change - if so AIR LEAK.

Make sure there's a good +12v at the coils when motors running.

Check thru all ignition connections for tight fit & corrosion!

Are valve clearances OK???

Run bike in dark and look for HT lead arcing/shorting out