1979 KZ650 problems

Hi all,

So i recently purchased my first bike.. a 1979 kawasaki kz650, and the thing is a beast. I've been working on it all week and ive confirmed that it has good compression and spark on all cylinders, so thats half the battle right there. Today i took the carbs off and cleaned them up, unfortunately i discovered that two of the pilot jets are totally stripped so i couldnt take them out, but i determined that they were not clogged up so i cleaned everything else up and put it back together. I reinstalled the carbs on the bike and she fired right up on the first kick. The engine sounded great and it had a nice strong idle so i took it for a short ride and maybe 100m later the engine stalled. I kicked and kicked but it wouldnt stay running unless the choke was all the way on, and gradually it got worse and worse until now it won't start at all except occasionally, if i keep the choke on and give it just the right amount of throttle while kickstarting it, it will stay running but if i try to rev the throttle it'll bog down, and if i let it go below 2500 rpm's it just dies off.

Now i cant even get it to sputter.

Did the carbs that i JUST spent 3 hours cleaning really get gummed up again? Or is there something im missing here?

Thanks!

Welcome aboard! A couple questions - do you have an inline fuel filter on the bike, and is the inside of the fuel tank clean (no rust or crud)? If the tank has junk in it and you have no fuel filter, it is possible that the carbs ingested some crud or rust and need to be cleaned again. If you do clean them, be sure to clean the tank and add an inline filter before turning the fuel on again. Ed

Thanks for the fast response! The gas tank is actually very clean, and yes there is an inline fuel filter and i put fresh premium gas in it today so i dont "think" it was a gas contamination issue.. although anything is possible with these old bikes. Its just strange to me that it ran so well and then suddenly it totally died..

So I just discovered something strange while pulling the carbs for the second time...

Two of the four float bowls appeared to be more or less totally empty. A third one had gas but not very much, and the 4th one had a normal amount of gas in it. Any idea what could cause this?

Check to make sure the float valves are operating smoothly, maybe they are sticking in the closed position. One thing you can try, but BE CAREFUL, is with the float bowl off one of the carbs open the petcock for a second to see if fuel will flow with the float in the down position. Again, be careful with the gas. Ed

Well I took the carbs a part today and sure enough, two of the 4 pilot jets are clogged up (the two stripped jets). So I suppose I found my problem, but now I need to figure out how to extract the THREE pilot jets that are stripped (yes.. i stripped a third pilot..). The common method seems to be drill the jet out a bit and then use a screw extractor, is this the best way?

Man these jets are garbage..