Airbox chamber blowby gas

[Guest]

I have noticed while cleaning out the airbox for my 1978 gs750, that the chamber at the top of the airbox has rust flakes and dirt/oil residue inside. This chamber seems to be inaccessible and I'm only able to shake small flakes out through the blowby gas tube entry point. I guess that it would be best if this chamber was clean. Is there any trick to sorting this problem? many thanks. Mike.

[carpetbagger]

I had the same problem, and I hope someone can offer a better answer than I have. I just kind of dug around as best I could with a small bottle brush type thing and blew compressed air until nothing else came out. Still pretty sure it could be cleaner.

[Dogma]

I had to get after it pretty aggressively with a coat hanger on both of mine. Put on some good music and grab a seat.

I gave it a good soaking inside with paint after it was clear, but that was probably a wasted effort. I didn't do any prep to get rid of the rest of the surface rust, and the paint I probably used didn't have any special rust-fixing properties.

[wymple]

Soak it with Evapo-Rust?

[bwringer]

Yep, just do the best you can.

And yes, if that tube rusts shut, it's a problem -- pressure can build up and cause leaks.


To prevent recurrence, ride more. Ride lots.

[mikebgs]

Thanks for the suggestions. I'll give Evapo-Rust a try or diluted hydochloric acid. It would be good to see a diagram of what the inside of this chamber looks like. The nozzle at the top of the airbox seems to not be attached to the outer casing. There might be an internal chamber/filter of some sort.

[mikebgs]

whats under the lid

I removed the top cap off the gs750 air filter box. Being pretty sure it was bad, I wanted to find out the extent of the rust problem.

It looks like the sealed off area at the top of the box has been eaten through, probably aided by the blowby gas trying to escape as the passage was blocked with rust.
The top of the box (under the lid) I have discovered, was not part of the air box circuit and looks like it's only meant to be a holder attachment point to the frame and a support for the blowby gas tube.
Now that the blowby gas route has rusted through, the gas would not have been entering the air filter box but instead escaping out the gap around the blowby gas in tube.
Thought I would post the pictures. Mike.

[Burque73]

Wow! Every time I see rusted parts like that I get very thankful for living in a desert, and more importantly, finding a GS that has been preserved very well.

My hose came loose that connects to that vent and I noticed my clothes and the bike stank a lot from the gasses. When I stopped at a traffic light I smelled the gasses as well. If you patch that up I'll bet you'll enjoy the ride a lot more.