Steamer Air Box Modification

[Sin_Tiger]

Finally got around to writing this up after having done it a few times now. So here is one method, not new to some but hopefully it may help those who are new to the delights of taking the bike apart just to change the air filter.

I have more U channel than I'm ever likely to use, so if you want to give this a go and rather than sourcing and buying a whole length of rubber seal, PM me with your details. This offer is open only to Steamer martyrs owners (one airbox only) with more than 20 posts on this forum, RAT forum doesn't count  and on a first come first served basis.

This will be linked in the "How To" thread as well.

[London_Phil]

Have you seen this?

www.youtube.com/watch?v=EVNzMYDYEBI

I'm sensing a theme here.....

Regards

Phil

[Sin_Tiger]

Hadn't actually seen the video. That's Tripod Tigeron this forum. His modification is a masterpiece of aluminium fabrication and welding but beyond the capabilities of most folk. If anyone needs a validation of the warning "don't screw with the air box volume" they should read his thread on ADV.

My suggestion is a little more modest 

[fishnbiker]

Tell me more about the U channel. Its application?

Thanks, Fishnbiker

[Sin_Tiger]

Tell me more about the U channel. Its application?

Thanks, Fishnbiker

Did you download the PDF file? If you are unclear on an aspect please let me know and I'll explain and edit the file if required.

[fishnbiker]

Sorry, I missed the notation about the PDF.

Seems like a great idea! I just have to wonder how that got missed by the design engineers, much like the front sprocket cover issue.
Thanks to people like you & Mustang that keep coming up with new improvements to make these wonderful machines more enjoyable.

My own method on the airbox was as fiddly as Tripod Triple's with a different outcome ... using a K&N filter housing off a Porsche 911 with a modified carb-side plate. Now covered with Uni Filter foam to keep out even more dust. Easily removed, washed & reassembled in under 10 minutes (plus actual washing time). The larger filter size allowed me to update the main jets to #130 for more top-end power with minimal torque loss. Still get about 47mpg (UK Gal)

[P3aK]

Sin_Tiger is 3.5mm throat on the U-list the smallest you could fit? I can find 3mm and 4mm. Would 3mm be to tight? Would 4mm be to big?

I'd take it apart and measure myself, but I need the bike to get to the store. Don't want to tear down half the bike just to redo it again :/

[Sin_Tiger]

I think 3 or 4mm would be OK, gee plastic moulding varies a little across the section but you normally have to buy a 1m length of anything. PM me your postal address and I'll send you enough to do the job.

[Mustang]

I think the question here might be length vs. width of channel ?

[P3aK]

Yeah the inner width of the channel (throat/mouth) is what I'm wondering about.

The stuff I find are 1.5mm thick, 8mm high (the two lips, could be cut to any suitable height) and 3 or 4mm inner width (throat/mouth).

Alright I'm gonna get one of each, if both could be fine, at least one of them should work.

Thanks for the offer but it'll take more time and probably money for you to send it then if I cruise by the store.

£10 total for 1m of each size ain't gonna break the bank....yet :)

[Sin_Tiger]

This is the stuff I used, with the lower part of the "U" being 1.6mm and a little rubber glue to join the two sections back to back it was a bit over 3.2mm, wich made it a comfortable squeeze with a 3mm gap between the halves.

It's no problem to post a bit, there's a bit on the bench ready cut, can't see it costing more than a Christmas ( I mentioned the C word) card, so just drop me a line if you want it.

[P3aK]

Yeah that's what I found as well.
Bought 1m 3mm and 1m 4mm for a total of £4.5 so I'm all set with the hardware.
Cut the airbox last night and tried to glue the rubber pieces back to back today (will see tomorrow morning how it turned out).

But I can already feel it's gonna be a bitch to get the things lined up and seal properly. Some serious corners/bends in there and I just can't see it making a proper seal. But.... time will tell. It's not like I can drive anywhere until I make it work.

[Sin_Tiger]

It's not as much of a bitch as trying to make the intake rubbers seal with mm to spare. A long thin screwdriver to lift the edges was enough for me.

[P3aK]

Guess I should contribute with my experience of doing this mod.

I disassembled the airbox and set it up for cutting. Made the cut so to take away 2mm, which ended up being more like 3mm, which was fine.

One thing to note: I made my cut as far to the left as possible. Meaning I was cutting more into the slope (curved) part of the airbox. I do NOT recommend anyone to do this.

What I gained was I got to keep the tiny plastic knobs that holds the metal mesh (that presses down on the air filter), they're still in place with about 1cm to spare. What I lost was a vertical cut on the left side. When I put the U-list on the left side, the back side of the U-list points at a 45 degrees downwards instead of horizontally. This made it very difficult to join the two strips of U-list together back to back.

I had to resort to gluing the right hand strip on the airbox first and let it cure, then put on the left side and hold it in place with different devices and gluing them together. I had to cut, glue, add material and so forth probably 3-4 times before I got a reasonable seal.

If i were to do this again I would definitely make the cut more to the center (not exactly in the center of course).

I can further report that 3mm gap or 4mm gap of U-list both works. I had to go with the 4mm due to the strange angle of my cut. It was simply more material that I could work with and it flexes a lot better then the 3mm. I do believe the 4mm also makes it easier to fit together when it's on the bike.


The mod seriously improves the access to a lot of things. I take apart the airbox first before removing the carburetors, makes it so much easier. And to fit the carburetor rubber gaskets on the air side is as simple as screwing a nut and bolt together now. It's sad that no proper aftermarket solution has been produced with something similar to this with perhaps a snap, hinge, or some sort of proper way of locking the two pieces together.

I can also say that Superglue is not recommended, I tried it, just out of curiosity on a short strip of U-list. If you bend it just once or twice, it cracks and breaks apart. So definitely go for some sort of rubber glue. I used something called Raychem, which might be difficult to obtain, but I had it lying around.


Funny thing is now the nuts on each side that holds that aux-air chambers to the battery box are the biggest annoyance to taking apart the air system. Why, oh why?! did they not put permanent nuts on the inside? I have to pull the damned battery to take apart the air system?!?! Argh! Anyone got a clever mod to that problem?

All in all, I'd do this mod again with a slight variation.

[JayDub]

I know this was a while back but, if you attach cable ties to the nuts next to the battry, its easy to catch them and hold them in place on re-assembly... also, puncture repair solution is good for glueing the rubber, rub it with sandpaper first.