1977-79 GS750 battery breather tube and airbox drain tube routing

[Guest]

Hey guys,

I'm putting the finishing touches on my bike to make it as complete and as close to original as possible. My bike hasn't run a breather tube for the battery or drain tube for the airbox in quite some time. I found a reference to the airbox drain tube in the factory service manual but the poor quality B&W photo doesnt seem to make things any clearer. I noticed there is a small "retainer" in the area of the left footpeg (right behind the rear bolt for the footpeg) and it looks like maybe the airbox drain tube might go through there. Can anyone confirm this? I'm also having trouble with figuring out the factory routing for the battery breather tube. The portion of the tubing that goes through the battery cage is clear to me but after that, I'm lost. I did see this decal that supposedly came with GS750s but it doesn't seem to be of much help either as there isn't anything on the frame or the engine to retain the end of the battery breather tube.

s-l400.jpg

[Guest]

Here's a picture of the retainer for what I suspect is the airbox drain tube. I saw on one of the Suzuki GS facebook groups that somebody else was puzzling the purpose of this retainer. some folks were speculating that it was for the rubber bumper that the end of the sidestand bumps into. seems like these bikes with the stock exhaust had the side stand bumper on the left muffler itself so a retainer seems to be the most plausible purpose of it. Anybody know the factory routing from the airbox to the retainer?

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[Rich82GS750TZ]

Get a sealed AGM battery and then you won’t have to worry about that tube. I’m not sure on the air box drain tube. What you say sounds right. As long as you route it so it can’t bind up, and can drain off- center, below the engine, so any dripping isn’t directly in front of the rear tire, but off to the side. My air box drain tube has a cap on it. If you continue with the regular battery, there’s maybe a squarish chase molded into the rear or the engine case on the right side, run that tube through there so it drain to ground, again, off-center. I once had that end of the battery drain tube end up resting on the exhaust somehow. The heat melted the tube and cauterized it. Oops.

[Guest]

Get a sealed AGM battery and then you won’t have to worry about that tube. I’m not sure on the air box drain tube. What you say sounds right. As long as you route it so it can’t bind up, and can drain off- center, below the engine, so any dripping isn’t directly in front of the rear tire, but off to the side. My air box drain tube has a cap on it. If you continue with the regular battery, there’s maybe a squarish chase molded into the rear or the engine case on the right side, run that tube through there so it drain to ground, again, off-center. I once had that end of the battery drain tube end up resting on the exhaust somehow. The heat melted the tube and cauterized it. Oops.

I’ll have to do some research on AGMs. I’ve never had any problems with the conventional lead acid batteries so I never gave it much thought. Thank you!

[cowboyup3371]

One of the better brands out there is the Motobatt; great battery and really good customer service

[Gorminrider]

but it doesn't seem to be of much help either as there isn't anything on the frame or the engine to retain the end of the battery breather tube.

You could just use a pull-tie or a piece of twisted wire and put the tube anywhere you want...?

Danger! Argumentative Opinion Follows: AGM's are ok I guess but the last new battery I chose to buy was a nice Yuasa wet cell ....

[Guest]

You could just use a pull-tie or a piece of twisted wire and put the tube anywhere you want...?

Danger! Argumentative Opinion Follows: AGM's are ok I guess but the last new battery I chose to buy was a nice Yuasa wet cell ....

I actually found the little tab meant for the end of the battery tube. I had to run my finger underneath the frame to find it but it’s there. I’ll probably get a new drain tube next time I’m out.