head gasket help

After talking to a older guy today about the turn over problem with my motorcycle after the valves dones plus new pistons and he said sounds like my compression is to high and need a new head gasket.

So I was looking around for a new head gasket for my 1980 kz750 h1. I notice that other may fit my motorcycle was wondering if anyone know what fit the may be cheap.

Yeah, people do say a lot of dumb things, don't they.

Assuming the static compression was to high because you are running 13.5 or 14:1 pistons, a new head gasket would do nothing for you. Assuming you are using stock 9:1 pistons with fresh hone and new rings, after break in then you have maybe 170 - 180 psi compression?

A lot more info would be really helpful.

".....sounds like my compression is to high and need a new head gasket."

Now there's a guy with a magic ear! :woohoo: :laugh: :laugh: :laugh:

Do a compression check to see what the actual compression is. If it is too high (rather doubtful) replacing the head gasket won't fix it, but there are ways to properly adjust the compression. Ed

I check them they was around 170 to 168psi on all four.

jeffecor wrote: I check them they was around 170 to 168psi on all four.

If it's anything at all like the KZ650 (and I'm betting it is) that is perfect. The KZ650 Kawasaki Service Manual calls for 156 - 185 psi. Check your KZ750 manual under Maintenance / Engine / Cylinder Block, Pistons / Compression Measurement. Ed

yes its stock pistons with new rings had the valves done and shim by a shop last year didn't replace the head gasket on it. The problem I'm having is the it well turn over once or twice then click for seconds then turn over again. Doing a compression test it was 168 170 170 169 on the pistons. I had the starter rebuild last year too. The guy at my work that rebuild some Harley motors said sounds like the compression is to high and the starter can't hand it. He told me that replacing the head gasket because it didn't replace it and that would lower the compression a little.

jeffecor wrote: yes its stock pistons with new rings had the valves done and shim by a shop last year didn't replace the head gasket on it. The problem I'm having is the it well turn over once or twice then click for seconds then turn over again. Doing a compression test it was 168 170 170 169 on the pistons. I had the starter rebuild last year too. The guy at my work that rebuild some Harley motors said sounds like the compression is to high and the starter can't hand it. He told me that replacing the head gasket because it didn't replace it and that would lower the compression a little.

Jeff
Dont open up that motor. Find someone else to get advise from. Compression is ideal so dont mess with it. Not saying you dont have a starter issue of some kind , but a head gasket with those numbers would be a shame to mess with.

jeffecor wrote: yes its stock pistons with new rings had the valves done and shim by a shop last year didn't replace the head gasket on it. The problem I'm having is the it well turn over once or twice then click for seconds then turn over again. Doing a compression test it was 168 170 170 169 on the pistons. I had the starter rebuild last year too. The guy at my work that rebuild some Harley motors said sounds like the compression is to high and the starter can't hand it. He told me that replacing the head gasket because it didn't replace it and that would lower the compression a little.

Hello out there! You are not listening (or reading)!

If it's anything at all like the KZ650 (and I'm betting it is) that compression is perfect. The KZ650 Kawasaki Service Manual calls for 156 - 185 psi. Check your KZ750 manual under Maintenance / Engine / Cylinder Block, Pistons / Compression Measurement.

In other words rather than breaking an engine that has perfect compression, why not simply look in the manual and verify that your bike's compression is perfect?

As Street Fighter LTD said DO NOT OPEN UP THAT MOTOR! There is nothing wrong with the compression, and the "older guy" who said there is a compression problem doesn't know what the hell he is talking about, so don't listen to him. Rebuilding the starter doesn't mean a thing; in fact these starters very rarely need to be rebuilt. Did you replace the components that make up the starter clutch? Is the battery full charged? Ed

what I'm talking about is i didn't replace the gasket when i had put it back together so it maybe to compressed and making the compression higher.

I had to replace to pistons the first 2010 year i had the bike after and had the two valve replaced in cylinder 3 and 4 too. After two years and after 10,000 miles later. last year i noticed that two of the intake valves was bent and i figure it would be best just to rebuild the whole top motor. Then after the rebuild it has problems turning over now like it would turn once or twice then stop start clicking for a few seconds then start turn over again. I torque everything to the manuals spec.

All I'm doing is replacing the heading gasket with a stock one.

jeffecor wrote: what I'm talking about is i didn't replace the gasket when i had put it back together so it maybe to compressed and making the compression higher.

I had to replace to pistons the first 2010 year i had the bike after and had the two valve replaced in cylinder 3 and 4 too. After two years and after 10,000 miles later. last year i noticed that two of the intake valves was bent and i figure it would be best just to rebuild the whole top motor. Then after the rebuild it has problems turning over now like it would turn once or twice then stop start clicking for a few seconds then start turn over again. I torque everything to the manuals spec.

All I'm doing is replacing the heading gasket with a stock one.

You cannot be serious so you must just be trolling. I admit it, you had me going there; I thought you were actually seeking advice. Ha Ha, you got me.

It should be obvious to anyone that if the compression is perfect, by definition it is not too high. Also, if the compression is perfect replacing the head gasket won't improve it - because it cannot be improved -it is already perfect. So since you still wish to replace a head gasket on an engine with perfect compression - have fun. :blink: :blink: :blink:

Jeff
Stop and think.
Yes I would have replaced the head gasket when I had it apart, but the outcome of reusing the original gasket is you have NO Leaks according to the compression numbers you posted, and if you gained any compression at all ( which I doubt) it would be a VERY small increase.
Not saying it now doesnt click or not turn over good , but the head gasket is NOT the problem. Just trying to save you the time and expense of replacing a gasket that is already working as designed.
As Ed said , start checking battery, battery cables and fittings, starter clutch ,and other electrical items BEFORE tearing apart a motor for no reason

I replace the battery this spring and the starter was rebuild because the bearings was bad and had a lot of play i didn't rebuild it my self a starter rebuild shop did it for me. i well check the wiring again and take a second video of the problem and post it.