Reproduction 2-hole airbox

[kp]

Mark, My 2 hole air box was cracked and stuff. I took it to a local plastic welder and he rebuilt the centre spacer where the metal fittings slip in. He also fixed a number of cracks and you wouldn't believe the result.
The material Honda used to make these air boxes can be welded unlike some plastics. I've had side covers welded as well some Kawasaki covers and every time the outcome was successful. I doubt a good plastic welder would be challenged. KP

[Wayne]

KP, I'm not sure if you meant your post for me or not but if so, I don't have a center section of any kind for my air box that's worth repair. The only one I have that is remotely together looks like it was thrown in a fire. It's twisted, burnt, brittle and cracked.

I would like to find a nice straight one. I can fix a crack or two no problem. I think I posted this somewhere already but here's the repair so far to my air box. Plastic welding wasn't an option as there were pieces missing and I would have needed a no relief air box for those pieces. Mainly, both corners were missing sections and someone had filled them with fiberglass and bondo. I re-fabricated the corner using ABS melted in acetone. I ground out good material and feathered it in both inside and out for strength. Once I get all the repairs made I'll brush ABS over the whole box to strengthen it and then give it the final wet sanding and shaping. Should look like new. Having a good center section will help me with the shaping of the corners and the lip that were missing at both ends.

This was before:


And after repair but not final sanded or anything:

[markb]

Wayne,
I've seen a few 3-hole boxes on ebay that were pretty reasonable with the top in bad shape.  I think the center section is the same.  Maybe you could find a crappy box with an OK center section.
Mark

[Wayne]

From what I can tell Mark the center is the same. I have been kind of watching for a decent one on Ebay. It's hard to tell from pic's how brittle the piece is. Hard to imagine some of those boxes getting so hot as to warp and burn the plastic back there. Had to have been from bikes backfiring on start up etc.

[kp]

Whoa! Nope I don't think a plastic welder will fix that. But gosh; you've done a nice repair job with that. Tell us how you do ABS all over the job. I'm interested.
I think backfiring and fuel leaks was what melted many of them. KP

[Wayne]

I'll go through the whole ABS repair procedure in a fresh thread once I get it completed KP. Don't want to toot my horn until I see the final product. I can tell you that it's very strong but also very time consuming. I guess you get out of something what you put into it.

[kp]

I look forward to it. These discussion Boards provide us all with so much info on what the other guy is doing. The old saying "you don't know what you don't know" is so true. For a simple example, I knew nothing about Aero Kroil until Swannie put me on to it. It's been a God send in my restorations and Ash's info on turning the fibre glass covering inside out was so simple yet I never knew about that.
This Board is certainly picking up in recent months and for the better Yabba Dabba Doozie  KP

[Wayne]

I got looking at the LPM Air Box I received. I think I could easily make this into a no relief, 2 hole box. If I get a chance between all of the other balls I have in the air I might give it a shot. If it works out perhaps I could have them send me a couple of boxes without mounting holes, that way I could do it without filling in the mount area and drill the 2 holes per side in the correct spot.

Update: I just contacted LPM to see if they will send me one without mount holes drillled.

[hondasan]

Of the early airboxes I have owned, mostly any warpage / melting has tended to be on the left side suggesting (to me) the problem stems from fuel in the box (blow back, fuel vapour condensing out in the box when not in use?) and being parked up on the side stand. Every used box I have had has been in poor shape, ESPECIALLY the centre plates which have often been beyond use. On one occasion I did repair a centre plate and bonded a sheet of .010" shim steel to it to add strength - that one has done another 94,000 miles so far since repair.

LPM did recently sell me a couple of centre plates, one of which fitted straight into a K0 box which had a destroyed centre plate - the fit was better than 95%, so okay for a "rider".

Fortunately, modifying a 3-hole box to 2-hole is made simpler by the fact that the "pads" on the box top to which the brackets mount appears to be the same size for both types, just different numbers of holes in them. Wonder why Honda made the bracket mounting pads so much larger than required for the 2-hole boxes?

Cheers - Chris R.

[Wayne]

I wish I could be so lucky as to get one 95% Chris. An old original center section fits perfectly into my lower housing and I do mean perfectly. It touched around the whole circumference of the box. When I put the LPM piece in it is sloppy and if I put it tight to one end, the other doesn't even touch, resulting in a gap.

Repairing my original 2 hole is going to require a near perfect center section so I can fabricate the lip in one area of the upper half. Patience is a virtue. I'll find one. Has anyone ever purchased a Yamiya unit? I wonder if they are closer to spec?

My original lower with a broken center from an original air box.


Nice fit all around:


LPM is smaller overall:


Leaves gaps:

[Wayne]

Karen got back to me from LPM. They are willing to send me an upper box without mounting holes drilled for about $31.00 CAD plus shipping. I'll go ahead and get one and we'll see what I can do with it.