Best way to clean exhaust ports - 79 GS850

[RustyTank]

Hello. I currently have the top end of my 1979 GS850G taken apart. I'd like to clean the ports, wondering what the best way to do that is? Here are some pics of the outside of exhaust ports 1 and 4. I'm assuming that all that black crud built up there is old gasket material? Again, what's the best way to get this stuff off? It's hardened on there pretty good. Is this work better suited for a machine shop?

 

[Steve]

Don't worry about the black stuff, just get the old gaskets out of there.

.

 

[RustyTank]

Don't worry about the black stuff.

I hope you'll excuse me Steve, I tend to be a bit neurotic when it comes to communication, I just want to make sure I understand. Are you saying not to worry about cleaning the inside?

just get the old gaskets out of there

So that is what I'm lookin at there in the pics, the old gasket material?

 

[RustyTank]

Don't worry about the black stuff, just get the old gaskets out of there.

Using a pair of needle nose pliers, pulled this out of #1. That must be the old gasket then, huh?

 

[storm 64]

I have found using a Plumber's Wire Brush. You know the ones they use for cleaning copper fittings. That will remove the hard stuff. Then I use some 120 grit sandpaper with my finger to clean it up. Since you have the head off, might as well Decarbon it...

 

[RustyTank]

I have found using a Plumber's Wire Brush. You know the ones they use for cleaning copper fittings. That will remove the hard stuff. Then I use some 120 grit sandpaper with my finger to clean it up.

Great info. I'm not familiar with that particular brush, I'll have to look it up. Thanks storm.

Since you have the head off, might as well Decarbon it.

That's where my head was at...no pun intended

 

[RustyTank]

I have found using a Plumber's Wire Brush. You know the ones they use for cleaning copper fittings.

Storm, do you mean something like this?

 

[storm 64]

This is what I talking about. Nothing fancy, just a good stiff brush.

 

[Rich82GS750TZ]

Rusty
We still don't know what bike you're working on, because you still haven't created a signature.

But, It looks like you've pulled more than one gasket out of #1 port. I've read of some people doubling them up. Which I suppose is what you do if one of your header pipes is tweaked out of line with the others. Whatever works, I guess. Just dig them all out and replace with new. They're like a crush washer, single use. Without the exhaust gasket, the port should look like my pic below. (Ignore the bolt welded to the broken bolt. That was a beautiful thing, when then weld finally held and the broken bolt came out)

 

[RustyTank]

Rusty
We still don't know what bike you're working on, because you still haven't created a signature.

Fair point about my signature, but I did mention the bike I'm working on in the first post in this thread. I'll make sure I fix my signature
Thanks Rich.

 

[bwringer]

Within thirty seconds of startup, the exhaust port will have another coating of carbon.

It's seriously not worth worrying about much, and on a reasonably healthy bike, it's somewhat self-limiting. Carbon seems to build up only to a certain point.

Don't damage the brass valve guides or the aluminum head by getting silly with a steel brush.

 

[headsbikesmopars]

Sandblasting or bead blasting will do good job of cleaning them up .

 

[RustyTank]

Within thirty seconds of startup, the exhaust port will have another coating of carbon.

It's seriously not worth worrying about much, and on a reasonably healthy bike, it's somewhat self-limiting. Carbon seems to build up only to a certain point.

Don't damage the brass valve guides or the aluminum head by getting silly with a steel brush.

I copy that bwringer. Thank you.

 

[RustyTank]

But, It looks like you've pulled more than one gasket out of #1 port. I've read of some people doubling them up. Which I suppose is what you do if one of your header pipes is tweaked out of line with the others. Whatever works, I guess. Just dig them all out and replace with new. They're like a crush washer, single use. Without the exhaust gasket, the port should look like my pic below.

Yeah, that's what I thought. I even went and found a parts fische online to make sure I was right. When I pulled this weird thing out of port one it scared the sh** out of me, I thought I was accidentally pulling part of the head apart, lol. It was coming out like threads that've separated, like a slinky, then I reminded myself there shouldn't be anything threaded in the port. So yea, I don't know what the hell this thing was. I'll see what the others look like soon.

Rusty we still don't know what bike you're working on, because you still haven't created a signature.

I fixed that signature boss

 

[Rich82GS750TZ]

I’m nobody’s boss. Just giving you a very light-hearted hard time. Hope you took it in the friendly nature in which it was intended. Following because I always learn something here. And best of luck with your rebuild.

 

[RustyTank]

I’m nobody’s boss. Just giving you a very light-hearted hard time. Hope you took it in the friendly nature in which it was intended. Following because I always learn something here. And best of luck with your rebuild.

Brother, I took it as a lighthearted reminder, and rightly so. I don't think you're the only one who's mentioned my lack of signature since joining the forum...two years ago. And I say "boss" with a wink and a nudge. In other words, thank you for the prodding, intended or not. It's all good :smug: