Float height and stalling at idle - KZ550 F1

Hello Kawasaki gurus.

This is my first post to this forum, having just recently acquired an 83 550 F1. The bike was in great shape but had been sitting for at least 2 years. It stumbled the 10 miles home.

The bike would run, but only at full or half choke. I cleaned the carbs (but never could find a float height in the Kawi manual so didn't mess with them), reinstalled, and got the thing to idle with no choke. I adjusted the idle screws, and throttle stop. Added SeaFoam to the fuel in the tank. An intermittent drip of fuel was happening at the left side overflow tube, and the exhaust for cylinder 1 was cold. Revved it a few times and both issues seemed to work themselves out. (I hope)

Took it for a ride around the block. Everything seemed fine but then the bike was completely unresponsive to the throttle and died. I tried starting it a few times with no luck. It appeared flooded. Pushed it back home and started it in the driveway no problem.

The oil was looking runny in the view window, so I drained it and sure enough: thin and full of gasoline.

Now I'm stuck. My theory is that the floats are out of adjustment or that the float needles are bad (they each had a very slight groove in them where they seat). I also thought that I should've cleaned the tank and petcock as well as replaced the fuel filter. There was a bit of old gas in the tank that I dumped new stuff on, along with the SeaFoam.

What would make the bike totally unresponsive in the 0-1/4 throttle range? I realize this is the range covered by the pilot jets, but I cleaned them. Could it be that my bad gas fouled them up again? Will the SeaFoam be enough or am I going to have to pull the carbs a second time?

I've tried to mention every detail, and now I've written a novel. Apologies. Anyway, any advice would be much appreciated. The weather in Oregon is only getting nicer and all I want to do is ride!

Thanks

my carbs were leaking gas into the crankcase too. The needle and seats were leaking.

Right. I figured it would be something like that. But what about the zero throttle response from 0 to 25% throttle? The idle screws (the one's with the plugs over them) don't seem to have an effect on the sound of the idle. Hmmm...Any suggestions, anyone?

Right. I figured it would be something like that. But what about the zero throttle response from 0 to 25% throttle? The idle screws (the one's with the plugs over them) don't seem to have an effect on the sound of the idle. Hmmm...Any suggestions, anyone?

Right. I figured it would be something like that. But what about the zero throttle response from 0 to 25% throttle? The idle screws (the one's with the plugs over them) don't seem to have an effect on the sound of the idle. Hmmm...Any suggestions, anyone?

Right. I figured it would be something like that. But what about the zero throttle response from 0 to 25% throttle? The idle screws (the one's with the plugs over them) don't seem to have an effect on the sound of the idle. Hmmm...Any suggestions, anyone?

I repeat myself when I'm in stress, I rep... just kidding. Check your plugs, they sound fouled out. Did you fix the fuel leaking into the engine? Do you have points or electronic ignition? Do a plug check they should tell you what's happening.

I would like to point out that if a cylinder isn't firing and the bike is operated, the gas has to go somewhere. Start by doing normal tune up stuff for an older bike. First, check compression and valve clearance (and adjust cam chain if it has a manual adjuster). Then do an ignition tune up and check voltage at the coils and check for spark. Check primary impedance of your ignition coils as well.

Yeah...sorry bout those repeats. Hit the back button too many times.

Anyway, thanks for the advice. To answer one question: the bike is electronically ignited. I thought I wasn't getting a spark but removed the plug wire from the number 1 cyl while the bike was running. Suddenly, I became the path of least resistance!

The bike has an interesting history. It's really been well maintained, which is not unusual. But it's last major tune up was in 2002. The guy I bought it from included the service records. In 02, all the filters were changed, plugs too, carb cleaned, etc. The bill was more than I paid for the bike! The interesting thing is that it had only been ridden about 100 miles since that tune up (according to the odometer reading on the service invoice). So...I'm thinking that everything is pretty much as it should be. I took it out today and it actually performed quite well. There is still some slight hesitation at the beginning of the throttle, but that clears up real fast. Again, when starting, cylinder 1 was cold until revved, and a couple drops of fuel were dripping from the overflow tube. I think it has to be incorrect float height on cylinder 1. Would this make sense to you guys given the symptoms?

I have another related question: where is the best place to purchase the rubber boots from the airbox to the carb? Mine are stiff as the dead. It was a reeeal pain to get the carb back on. I ended up using a blow dryer to soften the rubber, but because of the ordeal, I hesitate to remove them again, even if they really need it!

Again, thanks for the help.

Hey IS. I've got the F2, and it's been no end of fun, so I hope you get yours running!

Make sure to download the PDF of the clymer manual. You can either search for PDF Clymer 550, or just find Loudhvx's posts and it's in his signature.

Also - I found this in my clymer, and I figure this is as good a place to ask the question as anywhere.. which is the float level setting (the one where you have it upside down with a ruler)? 1 or 2? I imagine it's number 1...so what does the 7 +/- 1 mean then?



Oh.. and check with www.z1enterprises.com/ for the rubber carb boots. I used bicycle innertube and it's worked really well for the past 2000km though. My boots are actually getting nice and soft now too! Kinda wierd - they were hard as rocks when I bought the bike. :woohoo:

Post edited by: pyxen, at: 2007/05/16 09:42

Your float needles and seats have to be sealing
100% for the bike to idle properly.Also make
sure your petcock shuts off completely.If not
you can fill the crankcase with gas overnight.

Right - so I'm looking to measure the floats at 27mm, right?

I've got a vacuum petcock, so it's no worries there..and I think that the 550F1 has one too.

My floats definitely seal well, it's just a matter of having the level set too high while riding. the bike definitely doesn't idle properly :pinch: