Warning: Headache! ('82 kz550)

Well, here it goes. I bought my '82 KZ550 for $350 from craigslist. It ran ok and just needed a lot of TLC which for me was a great thing because this is my first bike. So, i've been doing all the little things that come up and fixing her up as the funds become available.

The bike has a slip-on and 4-1 header that was installed before I bought it. Since then i've added pod air filters (had no air box before) and plugged off the emissions lines on the top of the motor. I've also taken the carbs off and cleaned out the float bowls and whatnot of all the ancient varnished gas.

As far as problems go, the petcock is a bit screwy in that it works but doesn't deliver enough gas in the "on" position to keep the bike happy, so I have to ride with it in the "prime" position. The real issue i'm having is that it stumbles a lot until the bike is warmed up (and ridden for 10 minutes or so).

I know I still need to check and probably adjust the valve clearances before I attempt any carb tuning, but could you point me in the right direction for a guide or manual of some sort on tuning the carbs? I figure with the modifications I may need to re-jet them as well, but it'd be nice if I could get it at least closer than what it is right now.

I can tell through riding it and adjusting the choke and whatnot that it's running on the fringe of being too lean. spark plugs are whiteish and it almost runs better at half choke.

Also, where exactly are all of the adjustments on the carbs? I read something about US models having a plug over the idle mixture adjustment screw, and keep reading about e-clips and whatnot but have failed to come across them in my random tinkering. (Pictures would be doubly helpful here!)

Again, this is my first bike and i'm slowly learning all of the nuances of it. I work on my car a lot and am in school for mechanical engineering so I know i'm capable of doing the work, it's just nice to have some help!

Thanks for any help!
-Cory

(picture was before the pod filters, grips, mirrors, and whatnot)

Forgot the pic!

www.metrovationinc.com/christemple/KZ550.pdf

Here you go man, a complete manual on your bike.

I got mine, same year, same motor, and it has helped me alot.

That's quite a score for $350. Both of you guys have nice looking bikes.

You're absolutely right about the need to check your valve clearances before you delve into carb adjsutments, and I might also suggest checking your timing while you're at it. As for your fuel delivery problem, you might want to try cleaning out the gas tank (drain/remove petcock/put a little fresh gas in/shake it around a little/pour it out into a container) and also take the petcock apart and clean it with some carb cleaner. Remember to remove any rubber gaskets before applying the carb cleaner as it will melt the rubber. You might also want to get an inline filter installed on the output fuel line if you haven't already done so.

You'll need to check your jet sizes (the manual will have the stock sizes) and decide whether or not you need to rejet. I suspect you do. Whenever you run a 4-into-1 header with pods you'll need to get larger jets, but I have a KZ650 so unfortunately I don't know what the proper jetting for your bike is. I'm sure someone else will chime in here with that information soon...

Your bike originally came with #92 main jets, I believe.

Robert

Thanks for all the info guys! I went to check the ignition and found out I have the transistorized ignition, and also found out that the polarity on the magnets counts when I put them back in! lol. And i'm switching all of the (very stupid) Phillips head bolts to allen head. Looks better and are much easier to get in and out and whatnot.

Yeah, they are the stock jets, either 92 or 93 I believe, found that out when I cleaned the carbs.

Another note of interest I think I may need to re-build one of them, as it keeps leaking fuel out of the venturi when I park the bike for a long time (overnight). And for some reason it spat fuel out of the overflow tube when I was tinkering earlier, so I may need to re-check the float level and all that jazz. Any input on this issue or is "re-build it" the final answer?

And i'll clean the gas tank once I finish this tank of gas... just too much fun to ride it even with these small problems!

I did do a small thing, I adjusted the idle mixture screws (the ones under the metal plugs) and it is running a lot better, but I do really need to get the tank drained and off and check the valves... It will probably have to wait for 2 weeks though, next weekend is my motor swap for my car! Gotta spend some time working on the subaru!

Thanks again guys! Any more tips are greatly appreciated!

B careful...leaking fuel and hot engines, backfires and sparks have caused more than 1 fireball.

tooocool49723 wrote:

...keeps leaking fuel out of the venturi when I park the bike for a long time (overnight). And for some reason it spat fuel out of the overflow tube when I was tinkering earlier, so I may need to re-check the float level and all that jazz. Any input on this issue or is "re-build it" the final answer?
...Any more tips are greatly appreciated!

Likely excess fuel is getting past one or more float valves for whatever reason AND one or more overflow circuits is clogged or being overwhelmed.

Fuel may have also entered the crancase. :pinch:

If not already done, would sniff-test crankcase oil and check its physical condition to rule out fuel contamination. If in doubt, change both oil and filter, and disconnect fuel line from petcock, and do not run engine again until the carb issues are resolved.

Good Luck!

Yeah, here's a write up on the magnets, If you haven't seen it already.
kzrider.com/index.php?option=com_kunena&...d=4&id=134605#134609