Head gaskets

Do the gaskets go on dry or what have do you use to bond them?? a spray gasket shellac or a silicone??

Any tips would be great.

You will find differing opinions on this but what I used was ThreeBond silicone sealant (either formula 1104 or 1211, depending on whether or not I had a prior leak:) ) and this was for the base gasket only. The valve cover gasket and head gasket I put on dry. Others on this site will recommend sealant on all gaskets...some will recommend sealant on no gaskets. It actually may take you several teardowns to find the solution or combination that works for your bike(s):laugh:

Post edited by: Mcdroid, at: 2008/02/17 09:31

2bskor wrote:

Do the gaskets go on dry or what have do you use to bond them?? a spray gasket shellac or a silicone??

Any tips would be great.

If you mean the head gasket between the top of the cylinder and the head itself: they do make an ultra hi-temp copper spray on adhesive that is pretty good.

I used it on mine to stop the slow oil seepage along the gasket line that had been going on.

In most cases, if you use a scotchbrite pad and make sure the gasket faces are really clean (and they are not warped) the head gasket alone is sufficient.

wouldnt hurt to have the head and block milled .005" each to make sure everything is flat. a slight bump in compression is allways nice. check your cam timing if you do this as it may need to be adjusted, but thats part of any complete rebuild anyway IMO

i like this stuff in aerosol for head gaskets;)

A stock or replacement head gasket goes on dry .
The shiny surface on a new gasket IS a sealer .
If you had any leaking or seeping before , find out why NOW and fix it and all will be good .

wouldnt hurt to have the head and block milled .005" each to make sure everything is flat. a slight bump in compression is allways nice.

Why did you have to say that? As you can see from my Valve Adjustment on the Bench thread my head is on the bench right now. My car is in the shop now too, so when I go to pick it up later I will have to ask my mechanic about a machine shop. While on the subject of head gaskets, the original is metal while the replacement is paper with metal inserts. As I had no leaks before I plan on reusing the metal original, would this be a problem? Since my head now must go out for machining I have a little time to listen to the debate.

madderkaw wrote:

While on the subject of head gaskets, the original is metal while the replacement is paper with metal inserts. As I had no leaks before I plan on reusing the metal original, would this be a problem?

Do you mean the original is SOLID metal? The Kawi OEM's I have seen are copper sheets with a compressible center of rubber.

As far as reusing a head gasket that has been in service a while, most mechanics say to never do it. If you try it, I would recommend at least using the copper infused sealer agent similar to shown above in previous post.

However: I got a full top end gasket set for my 750 from old Bike Barn for about $50 which included a decent quality head gasket. I would not risk the royal pain a used head gasket can cause but it's your call.

MDawnz1 wrote:

A stock or replacement head gasket goes on dry .
The shiny surface on a new gasket IS a sealer .

It is as long as it is mating with a smooth, shiny surface on the head and cylinder where it has to seal.

I agree, a new gasket and a properly prepped head and cylinder (which are not warped) should seal fine without any external sealers added.

Do you mean the original is SOLID metal?

It looks like it's made af aluminum. It looks like 2 pieces pressed together with something in between, but I'm not going to pull it apart. It looks very clean and not damaged at all. It also looks to be 1000% better than the replacement that's brand new, but made of paper (maybe felt of some type) with the metal inserts.

Way back when, the thing to do for increased compression on a Greeves (two stroke Brit bike) was to hand lap the cylinder and head mating surfaces together and do away with the head gasket

Your used head gasket is already compressed and you aren't going to compress it any further. New head gaskets are fairly cheap (you already have one anyway) so why in the world would you want to take the chance of having to replace it again?

Conventional wisdom says solid copper head gaskets can be reused, nothing else can.

But, if you decide to reuse the old head gasket, be sure and let us know how it's working out after the first 500 miles

Well, that's not very encouraging. I guess I'll just use the new one.