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GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 12:11 pm
Author: DB990
Hi, new joiner here, recently fitted a new head gasket which subsequently leaked between the head and main barrel block. Turned out I had not fitted the oil seals in the 4 oversized gasket holes. They are the 2 outer most studs on each side of the engine that transfer the oil up to the cam shafts.

My gasket did not have these oil seals and there were no witness marks. Has anyone fitted these. What are they made of and what thickness?

I have measured the hole and it is 20mm. I have some neoprene seals but not sure if they will work.

Thanks for reading.

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 12:40 pm
Author: Julian_Boolean
I assume you mean the O rings that are on Z1000J engines, you don't need them on a Unitrak engine and neither the head nor barrels have the grooves for them.
Which head gasket did you use?

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 1:32 pm
Author: DB990
Thanks Julian, I used a "Gasket Set Top End Kawasaki GPZ 110 ZX110A 1983-1985". I was referring to the O rings yes. So do I assume that the gasket itself will hold the oil pressure on its own?

So I get my words right, I am talking about the gasket that is split in 2 pieces either side of the cam chain hole. the gasket has metal reinforcement rings next to the cylinders and has a bigger lip on one side than the other. There is no reinforcement around the engine studs that have the oil travelling up them.

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 2:33 pm
Author: Julian_Boolean
Yes that sounds correct - my 1170 Unitrak engine has Wiseco two piece gasket, no O rings, never leaked a drop of oil (though it's hardly been run for the last two years for other reasons)
I wouldn't use the head gasket out of one of the cheap gasket sets you get on eBay, use either a Kawasaki original pair or a Wiseco pair, use a new cam chain tunnel seal O ring as well.
Follow the manual when it comes to tightening up the head bolts, I think I did mine in 4 steps rather than the 2 the manual recommends, probably not necessary, but it only takes 15 minutes longer.

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 2:56 pm
Author: DB990
Awesome, I will do that then. Thank you. Here's a subsequent question - how hard is it to change the cam chain, mine is at the full extent of the auto adjuster and there is some backlash in the engine when you line up the timing marks with the arrows on the Cam drive wheels, I you don't know me but I am ok at reading and can use a spanner!

Regards

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 4:22 pm
Author: Simon Jones
I used a 1 piece gasket on my 1170 and a good sealer in the center channel never had a problem

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 6:17 pm
Author: zed1015
DB990 wrote:Awesome, I will do that then. Thank you. Here's a subsequent question - how hard is it to change the cam chain, mine is at the full extent of the auto adjuster and there is some backlash in the engine when you line up the timing marks with the arrows on the Cam drive wheels, I you don't know me but I am ok at reading and can use a spanner!

Regards

You can use a soft link/rivet link chain and thread the chain round the crank etc on the end of the old one but ideally you should split the cases and fit an endless one as the Hyvo soft links have been known to fail form being riveted too tight.
HOWEVER on your Unitack motor you cannot tension the chain without the camcover installed and even with the tensioner at full travel there will still be some slack with it off.
DO NOT fit the camcover with the tensioner fitted as you risk snapping the chain.
You must line up the timing marks, fit the cover and then fit the tensioner to avoid damage.
To check for chain wear you need to measure a length of chain and see if it is within the specs shown in the manual..
Those hyvo chain should last more than 40k miles.

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Wed Sep 11, 2019 8:39 pm
Author: DB990
Way more advice than I thought possible. Thank you very much. I will report back with the results.

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Thu Sep 12, 2019 8:53 am
Author: Julian_Boolean
I'd replace the standard auto cam chain adjuster with a manual one, it's a bit more servicing but I doubt if you're using it for transport.
The spring in the auto will probably have got a bit weak by now and also a manual one allows you to slacken the tension on the cam chain off enough to fit the cam cover without having to remove the tensioner.

Replacing the cam chain is a complete engine strip down as the crank has to come out, mine needs doing (which is why it's sat doing nothing for 2 years while I find the time to do it)

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Sat Sep 28, 2019 10:54 am
Author: DB990
Thanks for everyone who contributed to this thread. The engine is now running, after a few long evenings in the barn!. New head gasket fitted and shimmed the valves. Runni g sweeter than ever.

Re: GPZ 1100 UNITRACK Head Gasket Leak

Posted: Sat Sep 28, 2019 11:09 am
Author: chrisNI
DB990 wrote:Thanks for everyone who contributed to this thread. The engine is now running, after a few long evenings in the barn!. New head gasket fitted and shimmed the valves. Runni g sweeter than ever.



:party :grup :hol