Super Jet Fiber or metal head gasket?

[yamanube]

Which is better? I have a feeling my metal head gasket may have had a slight leak..not even sure if a fiber one is available but was curious as to which is better.

 

[Tyler Zane]

if i had a stock head i would buy an oem head gasket. or get an ada griddled head

 

[Waternut]

Is this a kawi? I didn't know yamaha's used metal head gaskets. Regardless, I would think there would be a massive thickness difference between metal and fiber gaskets.

 

[yamanube]

It is a 760 cylinder/head setup. I am unsure what material the OEM gasket is. If a billet/girdled head was in the budget I would definitely be running that.

 

[the WaTeRhAwK]

Fiber gaskets compress better when torqued , so in my opinion, will seal better under a low torque and normal compression application. Although, if you're running high compression for performance, you will need a copper head gasket and some 1211 to seal it with. Regardless of which type, When you install it, makes sure you clean all of the mating surfaces good with a very "hot" based solvent like lacquer thinner, chemtool B-12, etc.. And by "clean" I mean go over the same surfaces with a new rag area like ten times. Even though you can't usually see it with the naked eye, mating surfaces are porous and like to soak up oil residue. If they're not cleaned thoroughly, it will cause sealer to fail by not allowing it to cure to the surface(s) and grip them properly.

Also, if you're using 1211 sealer, allow it to set up for a full 24 hours in a moderate temp environment, before exposing it to compression and combustion pressures.

 

[Freakrider]

the oem 760 gasket is a triplicate metal one that works well but the last one I bought was 46 bucks....sometimes they can be re-used with a nice coat of copper gasket spray...

 

[Octane_114]

steal is what i run on a 750sx sp kaw with 190psi milled/cut stock head 26cc's and i used the copper gasket spray. havent had the first issue. have run this set up for years.

 

[the WaTeRhAwK]

I never had much luck with copper coat on head gaskets. It solves with fuel.

1211 or yamabond is the best stuff you can use for head gaskets.

 

[SUPERTUNE]

Fiber gaskets compress better when torqued , so in my opinion, will seal better under a low torque and normal compression application. Although, if you're running high compression for performance, you will need a copper head gasket and some 1211 to seal it with. Regardless of which type, When you install it, makes sure you clean all of the mating surfaces good with a very "hot" based solvent like lacquer thinner, chemtool B-12, etc.. And by "clean" I mean go over the same surfaces with a new rag area like ten times. Even though you can't usually see it with the naked eye, mating surfaces are porous and like to soak up oil residue. If they're not cleaned thoroughly, it will cause sealer to fail by not allowing it to cure to the surface(s) and grip them properly.

Also, if you're using 1211 sealer, allow it to set up for a full 24 hours in a moderate temp environment, before exposing it to compression and combustion pressures.

Copper headgaskets are NOT recommended for Yamaha OEM 701/760 cylinders.
The reason is Yamaha cylinder is a free standing sleeve and needs additional preload at the sleeve flange like a stock fiber gasket that uses a flanged over metal around the combustion chamber to accomplish this.
A OEM 760 headgasket are embossed at the sleeve flange as well.
ADA removable dome heads work because the domes are NOT flush with the head deck as they will protrude above the deck for pre-load on the cylinder flange.

If you machine a groove in the top of the sleeve flange, add in a stainless or copper wire o-ring that protrudes up, then using a copper headgasket will have a chance of sealing with the freestanding sleeve Yamaha cylinder.

I use 1211 for o-ring heads and basegaskets and coppercoat spray mostly on Yamaha 760, 650,750 & 800 Kawasaki's, and 951 Seadoo's all using the metal embossed headgaskets.

 

[the WaTeRhAwK]

A copper gasket should achieve the same effect, unless it's cut open too far, and I've never had copper coat make a good lasting seal on a cylinder head. Only on exhaust manifold fiber gaskets. The fuel always solves it in head gaskets, probably because it's "pressure fed", and then leaks with high or even moderate compression.

 

[SUPERTUNE]

I think you missed the point I tried to make.
I haven't seen any copper headgaskets that have embossing on them to support extra crush on the freestanding sleeve that a Yamaha 701/760 cylinder needs.
All of the copper headgaskets that I have seen are just a flat single layer of copper.

As far as coppercoat spray used with a OEM metal embossed headgasket works fine IF you have proper crush and sealing, fuel will not get to it to wash it out...

 

[the WaTeRhAwK]

As far as coppercoat spray used with a OEM metal embossed headgasket works fine IF you have proper crush and sealing, fuel will not get to it to wash it out...

Ok, with clean and perfectly flat and mated surfaces, a metal embossed fiber gasket sprayed with copper coat (which is not anaerobic, and remains "tacky" indefinitely, exactly as the indications on the can describe), torqued in sequence, evenly to nominal specifications, the fuel will make it in between the surfaces and wash it out. What exactly am I missing here? If I'm doing something wrong, please correct me, :dunno: because I would sure like to just be able to spray the stuff on a head gasket and make it work as well as it does on ex-mani's. :scratchchin:

 

[the WaTeRhAwK]

The only reasons it seems to work well on ex-mani gaskets is because it's where the majority of the heat produced by the engine is present, it's not exposed to as much raw fuel and pressure as it is around the combustion chambers, and it is cured solid by the heat before it's given the chance to solve. Since there's not as much heat around the cylinder head, as there is around the exhaust ports, it doesn't get hot enough to cure solid before the sealers' exposure to pressurized raw fuel can affect it.
Any sealer that can be solved with fuel, once it has "set" on it's own, is not a very good choice for sealing head gaskets IMO.
just sayin'. :dunno: