Gs1000G airbox measurements

[MrKaizer]

Hello everybody,

I recently bought a GS100G with sidecar. She runs but there are a lot of things that need addressing.
One of them is the rubber tubes (boots?) between the carburetors and the airbox. They have shrunk massively and are rockhard. After weeks of searching I was lucky and cmsnl had one in stock, but it feels like this was the last one on the planet. That's why I'm trying to make them myself.

I used the new one to make a CAD model and the prototype looks promising (sorry about the off-brand color, it's the stuff I had available ). But now I need some exact measurements from the airbox that I can't get because the rubbers on mine are glued in and I would like to keep the bike in running condition until I have a full set of rubbers.

It'd be really cool if someone who has a GS1000G airbox kicking around could measure the following things:

1. Material thickness of the airbox
2. Diameter of the holes for the rubber boots
3. Distance of all the holes to each other

If anyone is interested I can publish the CAD-files once they are done so other people can print them as well.

[gs7_11]

I have a spare GS1000G airbox, and will do the measurements for you. I'd be interested in a source for the rubbers, as you say, they're impossible to find.

Side note: despite what many people think, the 750, 850(CV) and 1000 airboxes are all different sizes. Confusion arises because the boxes have 750/850/1000 stamped on them, but the front plate is spot welded on after the box is stamped out. Had a few rows with Eblag sellers about this!

Also, the chrome end caps are different from 850 to 1000.

Pics show 1000G airbox measured against later 850 (CV carb) airbox.

[Dezza]

gs7_11 should go on Mastermind: specialist subject - 'Four cylinder 8-valve aircooled Suzukis 750, 850 and 1000cc, 1976-1983.' And I'm not joking!

[gs7_11]

4 minutes ago, Dezza said:

gs7_11 should go on Mastermind: specialist subject - 'Four cylinder 8-valve aircooled Suzukis 750, 850 and 1000cc, 1976-1983.' And I'm not joking!

I might win enough prize money to break even on parts I've bought. 

Probably not 

[MrKaizer]

gs7_11, thanks a lot!

But now I have to ask: Which one is which? I'm assuming the one with the bigger distance is for the GS1000G, right?

Could you please also put a ruler directly to one of the holes, for the inner diameter?

 

35 minutes ago, gs7_11 said:

Side note: despite what many people think, the 750, 850(CV) and 1000 airboxes are all different sizes. Confusion arises because the boxes have 750/850/1000 stamped on them, but the front plate is spot welded on after the box is stamped out. Had a few rows with Eblag sellers about this!

Also, the chrome end caps are different from 850 to 1000.

I assumed the same. Thanks for the heads up.

 

 

[gs7_11]

The hole diameter is 52.5mm

The hole spacing is 246mm from 1-4 spaced as 78-90-78

There's a bit of parallax error going on in the pics.

Edited July 25, 2023 by gs7_11
Typo

[Captain Chaos]

9 hours ago, gs7_11 said:

The hole spacing is 246mm from 1-4 spaced as 76-90-76

I lnow it's still early morning but somehow this does not compute 

[Gixer1460]

I think it should be 78 - 90 - 78 . . . . that would add up and is also the generally accepted carb inlet spacing for big Suzi's

[gs7_11]

1 hour ago, Captain Chaos said:

I lnow it's still early morning but somehow this does not compute 

Well spotted! 

I've edited the post.

[MrKaizer]

Your measurements were spot on, thanks again! I was able to print some more prototypes and they fit inside the airbox and over all four carbs very well.  I made the CAD files parametric, so it should be possible to make carb boots for the GS850, too. They seem to be hard to get as well. But I still have to make some adjustments to make them more "printable", 'cause it all went really sideways when I tried to print them in some other flexible material.

I was goin to post the current version here for now but the forum software doesn't seem allow .stl files. So I'll probably upload the files to thingiverse or printables once I'm happy with them. Btw, is there a "proper" technical term for carb boots, so people can find them?