77-79 GS750 Manifold Boots

[Anonymous]

Hey guys,

I've been lurking for a while and learned a lot from you lot.

I've taken off my intake manifold boots and I can't tell if they have any o-rings on them. I almost looks like one smooth surface.

If my o-ring has melted into the boot, what are some good ways of extracting it? Otherwise, what are my replacement options? I can't find anything on BikeBandit or CrotchRocket.

If I don't need any o-ring, what can I use to seal the flange to the cylinder head?

Thanks very much!

Patrick
1977 GS750

[duaneage]

Re: 77-79 GS750 Manifold Boots

Hey guys,

I've been lurking for a while and learned a lot from you lot.

I've taken off my intake manifold boots and I can't tell if they have any o-rings on them. I almost looks like one smooth surface.

If my o-ring has melted into the boot, what are some good ways of extracting it? Otherwise, what are my replacement options? I can't find anything on BikeBandit or CrotchRocket.

If I don't need any o-ring, what can I use to seal the flange to the cylinder head?

Thanks very much!

Patrick
1977 GS750

I used a needle to remove my hard o rings. THe dealer sold me 4 rings for 7 dollars

[ptm]

The intake boots that go between the carbs and the cylinder head are shown in the 'air cleaner' schematic - even though they don't attach directly to the air box. It looks like the 77 GS750 does have o-rings on the boots - Bike Bandit charges $1.11 for them.

Almost any auto parts or tool store will have a set of what look like heavy duty dental picks - one straight, one with a right angle bend, one with a curved hook, etc. They are great for things like removing o-rings, but any sharp pointed tool will do.

[KEITH KRAUSE]

Your bike does have manifold o-rings.
A toothpick should get the old o-rings out. Just don't use something that will gouge the o-ring groove.
Apply some hi temp bearing grease to the new o-rings. Torque to 6 ft/lb.

[snark]

I am, as I type, taking a break from changing mine. I got tired of fighting with the last screw so I'm taking a breather. My O rings were so flat that they looked like a part of the boot. I used a thin razor blade to carefully pry it out. It was so brittle that it came out in peices. Use the grease as mentioned above. Also, replace the original screws with hex bolts. They are easier to torque than playing with the old screws. Good luck.

[ptm]

Just don't use something that will gouge the o-ring groove.

Good point, Keith - you don't want to damage the groove and make it that much harder for the o-ring to seal.

[Anonymous]

Thanks for all of the suggestions!

I tried almost everything and I still can't get the o-ring out without damaging the rest of the rubber flange as well. I have a feeling it's the original oring.

It also looks like that last owner used some kind of a gasketing material. I'm not the first one in there because the phillips screws were already replaced by allen screws... thank god.

Anyhow, I think I'll be forced to buy new boots... $30 a pop @ BikeBandit. ouch.

Thanks everyone!
Patrick
'77 GS750

[KEITH KRAUSE]

Thanks for all of the suggestions!

I tried almost everything and I still can't get the o-ring out without damaging the rest of the rubber flange as well.

The o-ring sits in a groove that's completely metal. The face of the manifold, where it contacts the head, is all metal.
I hope your looking at the same area. We're not talking about the inside of the manifold with its "built in" o-ring that mates with the carb body.

[dgeorge]

Patrick, if you are not in a real big hurry and want to save some money you can get the boots from http://www.crotchrocket.com I looked at the fiche for you bike and they are $18.32 ea. that is a lot better then bikebandits $30 ea. but with crotchrocket they do not have any way of tracking shipment, and it takes about 2 weeks to get your parts.

[Anonymous]

Hmm... I'll try and take a pic tonight and show you guys what I'm dealing with. I'm definetely picking at the engine side of the boot.

I'll also check with CrotchRocket to see how much shipping is to Canada and I'm looking at a used source as well.

Thanks again,
Patrick

[Anonymous]

Ok here we go... from the picture it looks like the O-Ring is a seperate peice, but let me tell you, it's not coming out like a seperate peice :?

[KEITH KRAUSE]

The face of that manifold should be bare metal I believe. Looks like it has a thin coating of black sealant??
You're sure that your two red arrows point to soft rubber and not metal coated with a black sealant? After the bolts were removed, did the manifolds "stick" to the head? Order the o-rings. You'll need them anyway. The o-rings are sold seperately from the manifolds.
Check the manifolds for any cracking anywhere. If they're cracking or hard, you need new ones anyway.
If the manifolds are good and the o-ring really is surrounded by rubber, all I can think of to safely use is toothpicks, or a very small tipped screwdriver, if you're careful. A rubber o-ring, surrounded by rubber, just doesn't make sense to me though. :?

[snark]

That looks the way mine did when I pulled the boots. Try taking a THIN razor blade and CAREFULLY running along the edges of the O ring slowly increasing pressure as you go. That worked for me to get mine out.

[Anonymous]

The face of that manifold should be bare metal I believe. Looks like it has a thin coating of black sealant??

Yes, it did have some sealant that I had to srape/cut off when I pulled them off.

You're sure that your two red arrows point to soft rubber and not metal coated with a black sealant? After the bolts were removed, did the manifolds "stick" to the head? Order the o-rings. You'll need them anyway. The o-rings are sold seperately from the manifolds.
Check the manifolds for any cracking anywhere. If they're cracking or hard, you need new ones anyway.

Yes, they were stuck to the head. I had to "peel" them off a little. A bit of material was left on the head as well. I will try to scrape a bit more off, I'm just worried I will damage it more, though. Oh well, nothing to lose at this point.

They are pretty fexible, though... no cracks that I can see.

If the manifolds are good and the o-ring really is surrounded by rubber, all I can think of to safely use is toothpicks, or a very small tipped screwdriver, if you're careful. A rubber o-ring, surrounded by rubber, just doesn't make sense to me though. :?

Yes, it was strange to me as well. I'll keep trying all of your suggestion (I will try your suggestion also, snark... I'll run a box cutter on the edge, slowly and carefully.)

Thanks again, everyone!
Patrick
77 GS750