Topic: 750K Head Gasket Branding (Cometic v OEM)

[HughL]

Replacing my head gasket, I am not using an MLS headgasket.

Debating on Cometic or OEM (12251-300-306). They're both the same price but I'm unsure about which to pick. I know the cometic is a little thicker by about .01" but it shouldn't matter for my application.

What would y'all pick? OEM or Cometic?

[Finnigan]

I used OEM

[scottly]

The only 750 gaskets I could find on the Cometic website were for the crankcase covers and exhausts; no head gaskets.

[HondaMan]

I vote for OEM, or Vesrah.

[seanbarney41]

When I was building my 836, the only non MLS gasket that I could find was Cometic.  They appear to be  plain cardboard and don't really fit very well, especially since they seem to curl up when you look at them wrong.  Very poor quality appearance.  I have used Cometic brand gaskets on more modern engines and they looked and performed excellent, but I did not want to risk this suspect appearing part on my 836.  I finally found a 65mm bore stock style gasket from Yamiya.

[HughL]

Thanks for all the suggestions! OEM it is.

[PeWe]

My brown K2-75 with later cylinder and head (K6 style) got a Vesrah head gasket last time. 8 new high oil return o-rings too.

It was not a grey graphite gasket as so many times before.
It was different material, black and hard. I had my thoughts but trusted the brand Vesrah, it was a complete gasket kit (green package) I took the head gasket from.

I tightened it 28Nm (20.65 ft lbs)

Tested to retighten again the day after with same 28Nm, nuts did not move. I unscrew each nut 1/4 turn and tightened. One by one, from inner to outer.
That was 8000km ago. No leak.
That engine has APE studs.

I tightened my K6 with same torque when it had stock studs.
I should tighten with 20 ft lbs if it should have stock studs today.

[BenelliSEI]

A few years ago, when I was racing an MG Midget with a very hot 1293 c.c. “A” Series BMC based engine (we ran over 12.5:1 comp ratio) the Cometic Gaskets were the only ones that survived more than a few races. I could change one out in under 30 minutes! The small FORD 105E based engines in the Yellow Ginetta and Lotus 7 ran them too…… Always wanted to try one in a cb750, but never have.