Hello Everyone! I have a 1982 KZ550 and I am trying to get it in good working order. Here's a little back story leading to my problem. Originally my oil light would turn on if my rpm was below 2500. I called a shop and asked for some advice and he told me that my battery was most likely about to die. So I bought myself a voltmeter and low-and-behold, the battery was about to bite the dust. I got a new battery, charged it and installed it, and the problem seemed fixed. I took it out for a ride around the neighborhood and things started to go very bad. After riding for about 5 minutes my oil light problem came back AND my rpms went all crazy. For example, I was riding along at about 4500 rpm and I released the throttle to come to a stop, but the engine was still revving at 4500 rpm! sometimes it would come down after a few seconds, other times would take longer. I limped the bike home in an attempt to not damage it further. I checked the carbs and the float valves only a little while ago and everything looked good and clean. I am freaking out about this so any advice would be fantastic.
-Adam

 

Sounds like a voltage regulator is going bad. Get it running in the garage and put a meter on the battery terminals and see what is happening. Try to reproduce that same problem watching the volts on the meter. Does that bike have a seperate regulator or is it built into the stator? I'm not familiar with that particular model. Good luck and post results.

 

Oh I forgot......Welcome

 

Thanks for the guidance deej, I'll be able to check that later today and post the results!

 

Welcome to KF! I am curious as well. Maybe you have two separate issues. How are the cables? Are they sticking? And test out your switch for the oil (if you know you are on the correct oil level of course). Good luck

 

ok guys I checked the voltage across the battery at a few different rpms and here are the results:
Engine off: 12.6V
Idle, Engine Cold: 12.6V (1300 rpm)
*In my ignorance I messed with the idle screw when I first got the bike, so it is not set right.......
Idle, Engine Warm: 14.3V (1800 rpm)
Revved to 2500 rpm: 14.5V
Revved to 4000 rpm: 15.2V
Revved to 5000 rpm: 15.7V
a little high, huh?
By cables you mean the throttle cables, right? They are not sticking and the throttle handle snaps back to normal position when I release it. The oil light came on when the engine was warmed up, probably because the voltage across the battery was above 14.5V at some point, and that is the upper limit of the charging range, right? A voltage regulator should prevent that high voltage....so I have a bad regulator, unless someone has a different idea about what's going on, because I'm new at this. As far as the engine continuing to rev with the throttle off....I am still at a loss. Thanks for your help so far, I really appreciate it.

 

ok update:
I checked the valve clearance on all the cylinders and found that ALL of the valves on the intake side did not have nearly enough clearance, and that all the valves on the exhaust side were on the low end of the appropriate range. I ordered new shims and hopefully they will arrive soon. Is it possible that this was causing my engine revving problem? I am also looking for a voltage regulator...