Surging

Hi all,

Just rebuilt the carbs on a 81 kz1100a1. Bike has been sitting for about 5 years.

Got her running, and smoked like crazy.

Then all of a suddent the RPM's jump from 1k to 5K and just sit there. I turn the RPM adjuster down a little and drops and wants to stall so I adjust the RPM up again and sits there for a minute then all of a sudden back to 5K and this repeated over and over again.

I haven't ballanced the carbs yet, and I see this as a possible problem.

Any advice?

Thanks

George

Might be a big fat vacuum leak.Do the intake manifolds look at all cracked? Are they hard as a rock? Did you use a little sealer between them and the head? Are the intake boots (between carbs and airbox) soft, pliable and securely installed. (The airbox is hooked up, right?) Have you checked the fuel height (not float level)? Could also be clogged idle jets. They are really small. Did you blow carb cleaner or compressed air through each of them?
In case you are interested, there are some really good carb cleaning and adjusting articles in the file base. There is a button near the top of the screen that will take you there.

Thanks TexasKZ,

I think it's a float issue. I found that while she's running at 4K RPM if I disconnect the vacuum on the petcocke, she'll slowly come down but when I reconnect the vacuum she'll run high.

I also sprayed carb cleaner all around and nothing.

BTW, the emmisions have been bipassed, but the hole to the airbox was not closed properly. Any advice?

BTW, where in Tx are you?

When you test for carb holder leaks the idle speed must temporarily be set VERY low (less than 1000 rpm). This will ensure the slides are closed (or nearly closed) which in turn raises the vacuum level in the carb holders (because the engine is sucking air but not much can come through the closed slides). The combination of the increased vacuum at the carb holders and the low idle will amplify the affect of a carb holder leak and will cause the carb cleaner to stall the engine or at least affect the idle if a carb holder is leaking. Ed

Thanks Ed, I should have been a little clearer. I was at low RPM.

So quick question, when you test the float level with a tube, Do you do so on the bike, and do you use gas?

I know this sounds like silly questions but if I can use water and hook it up to my bench it would be much easier and won't stink up the whole garage.

You can do it on the bike or on the bench (if you make sure everything is level). Unfortunately, using water won't give you a very accurate level because the density of water is different than that of gasoline and this makes the floats rise to a different level than they will using gasoline. If you have a workmate or sawhorse that you can clamp a board to, and then mount the carbs on the board using old carb holders, you can to the test outside to reduce the smell and risk of fire indoors. Not a silly question at all. Ed