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Head gasket leaked on first run:(

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Jethro
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Joined: Fri Dec 25, 2009 1:26 am
Location: Helena, Montana

Post by Jethro » Fri Jun 10, 2011 11:15 am

Thanks Davo, That's were I put he o-rings and I put the gasket in just like you said. I guess I'm confused because it seems like the oil is begin pumped up through the holes for the two outboard rear studs. I'll have to check it out later on.

Thanks again, Jethro

305nutt
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Location: north vernon Indiana

Post by 305nutt » Fri Jun 10, 2011 11:01 pm

Jethro, probably the oil ran down the studs when you pulled the head off. I ran into a similar experience with the oil being on top of my pistons, but the motor ran flawless and didn't smoke, so I figured the excess oil ran down from the cam etc when I pulled the head up. I used ultra black silicon, it is oil resistant when I redid mine, I put a real light coat on both sides of the gasket and filmed the orings with it also. Good luck, let us know when you get it back together. nutt

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Jethro
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Location: Helena, Montana

Post by Jethro » Sat Jun 11, 2011 7:09 am

Thanks Nutt. Thats right, the studs are located right next to the rockers. That makes sense now. Thanks for the silicon suggestion. I was lying awake at 5 this morning thinking about what I'm going to put on the gasket. I have had a lot of people suggest some gasket compound called "The Right Stuff" anyone heard of it? Others have suggested using honda bond, hylomar, silicon etc.
Anyway, thanks again for the advice everyone!

GeorgeP1111
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Joined: Wed Jun 16, 2010 3:58 pm
Location: St.Paul, MN

Post by GeorgeP1111 » Sat Jun 11, 2011 10:44 am

FWIW I'm having the same issue on my "Refreshed" CA77. New Head Gasket & O-Rings, both were non-NOS. No adhesive was used on the gasket, but I did put Hylomar on the O-Rings. Torqued to 15lbs and retorqued over the next few days.

Got it installed and fired up last week. Ran thru the warm-up / cool-down cycles as suggest in some postings here then started taking it out for the easy neighborhood break in drives. Everything was Ok, no leaks. After about 20 miles of short drives (less than 40mph) I took it out on one of the larger streets for a 1 mile run at about 55mph and ended up with a leak at the front center of the head gasket. Yesterday I tipped the motor down enough to re-torque the head. When I reassembled the motor after the refresh I notices the acorn nuts were a bit sticky (torquing was jerky not smooth) so this time I removed the acorns and applied a tad of Anti-Seize to the threads/nuts and a stainless flat washer on top of the sealing washers just to make sure the nuts weren't topping out on the studs. Now the the torque was smooth and with multiple passes I ran them all up to 19ft-lbs. Put it all back together and out for a run.... Still Leaks, possibly a little worse :-(

When I torqued it this time I stopped at 19lbs (vs the 22 that LM suggested) because the stud front right (#6 in the manual) would not go any higher. #1-5 studs "Clicked" at 19lbs, but #6 would not with even one full turn. I had been going up in torque value at 0.5 ft lb increments and would get the "Click" with about 20 degrees of rotation on all, so when I turned #6 one whole turn I figured it was time to stop.

So, now I'm going to go out and pull the motor out today. I'll pull the head (and maybe the jugs) and try the see where/why I have the leak and also take a look at the #6 stud and figure out what the heck is going on. Next week I'll order up new Gaskets/O-Rings and start over.

So I too am interested in suggestions on the stud and sealants.

tnx
George

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Jethro
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Location: Helena, Montana

Post by Jethro » Sat Jun 11, 2011 1:43 pm

Hey Paul. Thats interesting about your #6 stud. Not sure what to say about that one. As far as your gasket goes though, you might not need new ones. A local guy that specializes in vintage bikes here told me yesterday that you can often times reuse them, especially right after a rebuild. I pulled my head off the other day and the gasket actually looked good, barely squeezed around the cylinders. One thing to look for is sunken cylinder sleeves. I looked at an oem head gasket the other day from Western Hills Honda and they wanted $50 for one. Pretty steep. Anyways post your results here when you get if figured out and I'll do the same.

Good luck,
Jethro

GeorgeP1111
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Location: St.Paul, MN

Post by GeorgeP1111 » Sat Jun 11, 2011 10:07 pm

Well I dropped the motor and pulled the head. The gasket was covered in oil, but as others had said on here that probably happens the minute the seal is broken on removing the head. The gasket "looked" like new and so did the O-Rings. It's a mystery.

I'll order up a new gasket on Monday as well as new O-Rings and seal it this time before reassembly. I'll check the head and mating surface for flatness also.

I also pulled the #6 stud. Double nutted it and it came loose with a "Snap". Took it out and it too looked great, threads were clean and in fine condition. Shaft was true and straight with no signs of twisting. I'm thinking that maybe I should cut a piece of pipe to put over the stud (to take the place of the head) and attempt to torque it to the 19ft-lbs and see if that tells me anything. I did measure from the top of the studs to the top surface of the head and found that the #6 was 14.36mm and #8 was 12.49mm (and most of the others were close to that too), so either #6 was never screwed all the way into the case or it's being pulled out of the case. This too is a mystery.

George

Narly9999
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Joined: Thu Feb 10, 2011 4:17 am
Location: Fort Wayne IN

Post by Narly9999 » Sun Jun 12, 2011 9:32 am

Ja know what, I had a Kawi KL250 1981 four stroker. I rebuilt that and was told to buy new head bolts because they were made to strech. I did as advised and don't think I had a head leak. I've always thought about this when I see you forum people talking about leaks and none seem to be buying or having a machine shop make them new head bolts to spec. Which brings up another question, How often are people visiting local machine shops? I've had a few special things made by them for special purpose and the cost was fairly minimal. My experiance is alot of them guys love to make STUFF! It's what they do! The shop I use, the guy does it when he has time between bigger company jobs. And they understand torq and tensil strength and metelurgey. It's their job. Hmmm, Just asking. =-)
2000 ZX12-R Kawsaki/1966 Dream 305 CA77/78

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