warning cometics head gasket

[peteracing]

Installed a few cometics .067 thick head gaskets on rx-1 ; no problems.
Those were made of 1 alu. plate sandwiched between 2 steel ones. Last
week, received wat SEEMS to be a newer version (.065 thick) made of 4 layers . Installed it and put together complete turbo kit, started engine
and :shock: oil dripping on the floor Check for the leak, found it : front left of eng. head just beside timming chain... I compared
a GENUINE YAMAHA with annother cometics i have and found a desing
flaw : the oil pass going to cams where the restrictor hole is in the gaskets
has no "embossement" around that restrictor :shock: the YAMAHA one
is embossed .... There is also a rivet (holding the gasket together) that
is at wrong place it gets kinked in between head and top of cylinders.
So if you have a cometics gasket matching that description, compaire it
to a yammy before you install it caus' it will PISSSSSSSS oil...

 

[devin]

gasket

was that new .065" from MCX .??

 

[peteracing]

from a yammy dealer in western canada. nothing to do with it...

 

[kip]

Peterracing.... not sure you have the latest gaskets.... call terry at bender.... my sled had same problem.... latest version works well , anyway only 3 passes on it...

 

[BlueByYou2000]

Interesting. I just installed a .074 Cometic for my CPR turbo. Fired it up last night and leaking in the exact same spot. However, we removed the valve cover and cams and found bolt #5 was only torqued to 14 lbs. We loosened every bolt in the head and re-torqued. Center bolts have a spec of 105 degree wheel, if you dont have one, the torque ends up at 37 lbs. The outside bolts mounted internaly under the valve cover have a spec of 140 degrees. This ends up in the 45 lb range. If you forgot to degree (or torque) the bolts or any bolt, after the initial 14 lb starting point, that would make your motor leak as mine and yours did. We missed one bolt that had 14 lbs only on it and all the other bolts were degreed, so effectivly the one with only 14 lbs wasnt even tight. You may want to check that first before removing the head. This was the new style cometic .074 gasket. I was bummed as Im sure you are now, but Im glad it was as simple as it ended up being. Good luck, keep us posted...BBY

 

[peteracing]

BBY did yours stopped leaking? i did not remove head yet but torqued all
bolts to specs ( did a few of those without problems). the gaskets i have
are wrong , i bet you a on that

 

[BlueByYou2000]

Yes, mine stopped leaking. THANK GOD. I took it up to 5000 for about 2 minutes, no leaks. Runs great. I will keep a close eye on it when it gets under load. Ill keep my fingers crossed...BBY

 

[peteracing]

Changed that cometics gasket today and leak fixed!
The way that gasket is designed makes it IMPOSSIBLE NOT TO LEAK :shock: Those advertisements about GENUINE PARTS is sometimes
true

 

[givemeaboost]

Head gasket

Just wondering if anyone knows the thickness of the oem gasket, Ken.

 

[devin]

gasket

stock one is .023"

 

[peteracing]

E- mailed cometics yesterday, said that they are investigating... 8)

 

[BlueByYou2000]

Put 100 miles on over the weekend. the New head gasket works great. Hope you get your problem solved. I do have an extra .074 if someone is looking for one...BBY

 

[ken_climb]

A bunch of guy's in BC area have been using two oem yamy gaskets sandwiched and have had no problems at all.Myself personally for a year now.

 

[sledheadgeorge]

I put on the 2 yammi gaskets on for one year now and have had no problems.

 

[peteracing]

I had to replace that cometics so i tried 3 :shock: yam. gaskets
(more then .075") i will let you know if it held together