81 KZ550 LTD from Upstate NY

Hey all,

Name's Matt, from Schenectady NY but living near Poughkeepsie and attending school at Clarkson University in Potsdam NY, really north.

Picked up a 1981 KZ500 LTD on Sunday night, 21k miles. Has some character, but runs, is inspected and has a clean title.

Only thing that I've noticed that seems to be wrong is that when somewhat cold, the engine will rev up to 5 grand and hold when it is in neutral or the clutch is pulled in. Even when riding, pulling up to a stop sign with the clutch disengaged will cause the engine to rev up.

I adjusted the idler screw on the throttle body, and that seemed to help a ton, but it did happen once more, and when I watched the throttle body the butterfly valve wasn't moving at all as it revved up.

Anyways, here are some pictures. Plans are to debadge (if possible, I see the gas tank badges are screwed in) and paint the tank and a few other pieces to make it look nicer. Just a cruiser to get into riding and save some gas.

Any tips/tricks I should know about the bike is greatly appreciated! I am just jumping in feet first right now.

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Welcome aboard. Looks like a good bike to get started with. Good score.

You probably should put a thread on your problem in the technical section because it will probably yield more responses from those who know such things.

What you describe sounds like an air leak to me. Could be anywhere from your aircleaner box to the o-rings between the carbs and head (if your bike has those). Those o-rings and boots on either side of the carbs get hard with age and will then leak. If they are hardened tightening the clamps won't help. I would suggest getting all new boots and o-rings to start with. If it still revs after that it could be that the carbs need cleaning--dipped in Berryman's for 24 hrs and cleaned really well. This is basic maintenance that should be done to a thirty-yr old bike when you first obtain it. It helps to establish a base-line with the bike as you begin to trouble shoot such things. There may even be a tutorial somewhere on how to clean the carbs. I don't really know yet because I am a newbie too.

Welcome to the forum, look around, use the search function because there is a lot of great info to be had.