Intake manifold boot gaskets.

[Outlander]

Last night I was doing some thinking. I have 32mm cv carbs on my 80' gs550. I know that leaks can form from old o ring gaskets causing bad performance, poor idle, and general overall headaches. Buying a set of them is cheap enough, yet, I know, in time, they will once more have to be replaced.

So, the wife tells me to check her anti-freeze in her car today. So I go out, and look. While under the hood, I look for leaks, from hoses, etc. I then looked at where the thermostat is. I get to thinking. 2 holes. Intake boot on the scoot has 2 holes. Relatively small opening, scoot has a relatively small opening. By george! If I can find a thermostat gasket to place in between the cylinder opening and the intake manifold boot, I could have a permanent fix! So, I went looking. I believe I can find a gasket with gasket cement that will fix this problem once and for all.

Do any of you think that this could be feasible? I don't see why it wouldn't work. And would be a far site better than an O ring.

Just my thoughts.

[49er]

Last night I was doing some thinking. I have 32mm cv carbs on my 80' gs550. I know that leaks can form from old o ring gaskets causing bad performance, poor idle, and general overall headaches. Buying a set of them is cheap enough, yet, I know, in time, they will once more have to be replaced.

So, the wife tells me to check her anti-freeze in her car today. So I go out, and look. While under the hood, I look for leaks, from hoses, etc. I then looked at where the thermostat is. I get to thinking. 2 holes. Intake boot on the scoot has 2 holes. Relatively small opening, scoot has a relatively small opening. By george! If I can find a thermostat gasket to place in between the cylinder opening and the intake manifold boot, I could have a permanent fix! So, I went looking. I believe I can find a gasket with gasket cement that will fix this problem once and for all.

Do any of you think that this could be feasible? I don't see why it wouldn't work. And would be a far site better than an O ring.

Just my thoughts.

Any gasket material that is fuel compatable and will stand moderate amounts of heat should work fine. I'm not convinced that the gasket cement will last the heat cycles over a prolonged period though!

The factory setup is designed for quick replacement of the boots. The system will only last as long as your boots remain pliable and crack free.
If you cement a gasket and it does stay sealed, you will have a PITA scraping job to remove the old gasket from the cylinder head mounting surfaces.
I would just fit the correct OEM replacement o rings and forget about them for many years of operation. The OEM rubber is designed to take the heat.

[Dogma]

Any gasket material that is fuel compatable and will stand moderate amounts of heat should work fine. I'm not convinced that the gasket cement will last the heat cycles over a prolonged period though!

The factory setup is designed for quick replacement of the boots. The system will only last as long as your boots remain pliable and crack free.
If you cement a gasket and it does stay sealed, you will have a PITA scraping job to remove the old gasket from the cylinder head mounting surfaces.
I would just fit the correct OEM replacement o rings and forget about them for many years of operation. The OEM rubber is designed to take the heat.

I agree. The o-rings take 20 years to go bad, and they're cheap. I'm sure they seal air and fuel mist better than paper too. I don't see a need for an alternative.

[bwringer]

This seems like a solution in search of a problem that doesn't exist.

The main reason to use o-rings like this (a grooved flange seal) is that the shape and dimensions of the intake are the same every time. The o-rings compresses into the groove on the flange, and the boot is supported by metal-to-metal contact with the cylinder head.

O-rings are cheap, effective, and work perfectly well for 10-15 years, so there's little point trying another type of seal.

[PAULYBOY]

I was told by the old timers 20 odd years ago when I started in the car bis that if you use the right gasket material you won't need any type of goo. If you do need goo, use permatex red high heat for intake and exhaust work, and only on one side. Otherwise, the heat cycles will tear the gasket itself up as it tries to creep those few thousandths of a millimeter.

[49er]

I was told by the old timers 20 odd years ago when I started in the car bis that if you use the right gasket material you won't need any type of goo. If you do need goo, use permatex red high heat for intake and exhaust work, and only on one side. Otherwise, the heat cycles will tear the gasket itself up as it tries to creep those few thousandths of a millimeter.

Hey, careful with that word OLD.

I made a thin cardboard gasket for the chain tensioner mount flange at my last rebuild. The Vesrah set I was using didn't have one. I smeared a thin coating of GP grease on both sides and bolted it up. Hasn't leaked in 8K of operation since. I expect the other rubber seals on the tensioner to leak before the cardboard one does!

[PAULYBOY]

I started in the car parts biz as a second career at the age of 27. What I meant by old timers is those that had been doing it much longer than I.
I forgot about the trick of using axle grease to keep gaskets in place during assembly. Dang, it also keeps the gasket "floating" so it won't shear from dissimilar metal movements. You sir, are a very young at heart GENIUS!!

[49er]

I started in the car parts biz as a second career at the age of 27. What I meant by old timers is those that had been doing it much longer than I.
I forgot about the trick of using axle grease to keep gaskets in place during assembly. Dang, it also keeps the gasket "floating" so it won't shear from dissimilar metal movements. You sir, are a very young at heart GENIUS!!

Thanks!! I do like your custom paint job. Have been considering going the same way with the 1100 when I do the resto.

[PAULYBOY]

Thanks!! I do like your custom paint job. Have been considering going the same way with the 1100 when I do the resto.

Thanks for the paint compliments. I'm currently in the process of painting the bike gloss black, and putting some illustrations that are a mix of tim Burton's work in Nightmare Before Christmas and the Mexican tradition of "Dia de los Muertos" on the tank, side covers ,front fender, and rear light housing. I hope to post pix when I'm done.

[Calvin Blackmore]

Um a GASKET like that used in a thermostat is impermeable to liquid yes?

likely not to an air yes?

[bwringer]

If you were trapped in East Bumhole with nothing but a rusty razor blade and an old cereal box, then sure, a home made intake gasket would get you home just fine. It would probably work pretty well for a while, too.

There's just absolutely no reason to do this in a world where you can still get Viton o-rings delivered directly to your home or office in one or two days for around $0.30 US each: http://mcmaster.com

After the apocalypse, I guess I'll have to defend the supplies in my garage from raving armies of starving lunatics looking to re-create Mad Max. Either that or defeat their leader in single combat, thus earning their fear and devotion.

[Griffin]

The Yamaha XJ engines have carb boots that outwardly look identical to the boots on most GS models. The only difference is that they don't use o-rings to form a seal, they use a flat gasket. It seems to work fine for them. I haven't heard of any guys on the XJ forum machining grooves into the faces of their boot flanges to install o-rings.

I guess what I'm saying is if the OEM style part is available, use it. It was designed that way for a reason.

[mighty13d]

I'm not convinced that the gasket cement will last the heat cycles over a prolonged period though!

My Valve cover gasket on my gs850 was cemented on and I'm positive it hasn't been off in very many years if at all. That thing was a PITA to take off and I spent hours scraping it even with gasket remover. I wouldn't worry about it lasting.
On that note, I still don't think it would be a better idea than the original o-ring that cost almost nothing, works great for 20ish years and is simple to change later on. Unlike a cemented on gasket.

[hkeni]

the only true gasoline resistant sealant is hylomar. permatex also markets it in a small tube. buy the aircraft grade or racing spec hylomar..some guy sells on amazon , check that out as well.

[Zook]

Be VERY careful using Hylomar as it doesn't harden and if used liberally will float through the engine and get stuck in places you don't want it.