Engine won't turn over.

I recently purchased a 1980 KZ750H/4 It was not running at the time. It had been sitting for about 4 years. I'm trying to get it to turn over but when I hit the start button it just sounds like it is trying to turn over but can't. I bridged the terminals on the solenoid and I get the same thing so I think I have ruled out a bad solenoid. I am wondering how I go about turning the engine over by hand to make sure it isn't seized? Any and all help is very much appreciated.

Thanks,
Jeremiah

Try putting the bike in 3rd or 4th gear and rock the bike back and forward and it should turn over...

Okay, I just tried to shift the bike into gear but it will only go into first and neutral. Any advice?

Bike has to be rolling when shifting to #2 and up. So roll it and try again.

Then you can start trying to release the stuck clutch plates.

JCFrancis wrote:

I recently purchased a 1980 KZ750H/4 It was not running at the time. It had been sitting for about 4 years. I'm trying to get it to turn over but when I hit the start button it just sounds like it is trying to turn over but can't. I bridged the terminals on the solenoid and I get the same thing so I think I have ruled out a bad solenoid. I am wondering how I go about turning the engine over by hand to make sure it isn't seized? Any and all help is very much appreciated.

Thanks,
Jeremiah

Hello, Jeremiah, and WELCOME to KZR!
We're glad you're here!

Some thoughts ---

A low battery might be reason engine won't crank over.

If decide to jump from battery in another vehicle, be sure the engine in the other vehicle is NOT running and that the ignition switch in the other vehicle is turned OFF.

Easier to spin bike engine over with spark plugs removed.

If engine seems "frozen," can spray PBBlaster or Kroil into sparkplug holes, and allow to soak for a few days (replenishing the spray daily). Could use Marvel Mystery Oil or ATF instead, but imo the PBBlaster or Kroil is better for this purpose.

Never twist on the bolt-head from end of crankshaft to attempt rotating the crank, with or without sparkplugs in place.

The usual method for hand-rotating the crankshaft is by using a 17mm wrench on the "fake" nut supplied for such purpose during routine maintenance. But the 17mm nut is intended for rotating a functioning crankshaft, and not intended to break loose a frozen crankshaft.

Good Luck!

A bike sitting 4 years.... hmmm, only one way I'd go about it....

Remove the timing chain adjuster....
Remove the head and all other components down to the cylinder... Poor some oil or as others recommended solutions if bone dry/crusted/rusted...

May just be your timing chain is bunched up at the crank gear... May be a shim has relocated under one of the cam lobes...

While in neutral, either use the 17mm nut under ignition cover (See kz900 image) or while pulling the timing chain taught against the crank gear, watch the pistons rise and fall.

NOTE: Don't force it! Rotate forward, not backwards. Take your time for your not in a race or a pit crew member where time is everything....

OMR

Well I was using the 17mm nut to rotate the crankshaft, and it seemed to me rotating without a lot of effort however I snapped the nut off and broke the other bolt as well. So, now I have more of a problem than I had before. :laugh:

JCFrancis wrote:

I recently purchased a 1980 KZ750H/4 It was not running at the time. It had been sitting for about 4 years. I'm trying to get it to turn over but when I hit the start button it just sounds like it is trying to turn over but can't. I bridged the terminals on the solenoid and I get the same thing so I think I have ruled out a bad solenoid. I am wondering how I go about turning the engine over by hand to make sure it isn't seized? Any and all help is very much appreciated.

Thanks,
Jeremiah

Pull the spark plugs and pump the kickstarter.

JCFrancis wrote:

Well I was using the 17mm nut to rotate the crankshaft, and it seemed to me rotating without a lot of effort however I snapped the nut off and broke the other bolt as well. So, now I have more of a problem than I had before. :laugh:

That's why I use the kickstarter....

There is no kickstart...

JCFrancis wrote:

Well I was using the 17mm nut to rotate the crankshaft, and it seemed to me rotating without a lot of effort however I snapped the nut off and broke the other bolt as well. So, now I have more of a problem than I had before. :laugh:

you broke the 17mm one?
how the hell did you do that?
were you standing on it?

Yes, I broke it. No, I wasn't standing on it lol. I was just using a normal ratchet... Not a breaker bar or anything.