Carburetor to airbox boot

[hangtime]

Howdy everyone,
Could someone help me out with some dimensions please? I would like to know the size of the flange where the carb boot meets the air box. And the distance from the bottom of the airbox flange to the bottom of the flange that attatches to the carb, I guess you could call it the offset on the horizontal axis. And last, the distance from carb end to the airbox end or overall length. The boot for the kx450f isn't even close, so I'm hoping I can make a new mounting surface on the airbox and run the KX500 boot between the two. From what I can tell on the Kawasaki microfiche the 500 mounting surface is smaller than the 450, this is better than too big.

Thanks

[demographic]

I am not exactly sure what your asking so have taken some pics to clear up what I am measuring, if I can help I will.

[hangtime]

Thanks Demographic,
I'm glad someone finally put this post out of it's misery. Those pics are exactly what I needed. I attatched some pics of my own. The pic of the cut frame was a nervous one, that is why I call it the "point of no return". The airbox pic shows how the 450f boot wasn't even close. With a KX500 boot being a smaller diameter than the 450f I'll be able to make an adapter plate that will cover the original opening and allow for the 500 boot and filter. If you're ever around California central coast you can take it out for a day.

[demographic]

Ahhhh, good stuff

So you kept the 450 airbox with the biger hole in it, made up a blanking plate to fit the smaller carb boot off the 500.

Keep those pics coming as it's an interesting project.

Have you seen this page with pictures of Service Hondas?
theres some pics of the Y piece that it looks like you need to build to get round the exhaust.

http://www.clubphoto.com/perl/app.pl/albums/large_image_view?id=2429935&link_code=sa01_17

[hangtime]

Good link,

Man there are some spendy bikes there. I think I will try to machine two pieces of billet to slip inside each lower frame tubes, then machine a bend in them to meet the downtube, and maybe box the end of the downtube for some extra added strength.
I don't know if it would be any easier to get some square stock tube bent. If you notice the two lower frame tubes are not square to the frame or each other. They actually have a twist to them.
The good news is the cases fit perfectly between the swingarm. All I did was drill out the cases for a larger swingarm bolt (15mm vs. 17mm).

[demographic]

Instead of using box section could you make up y shaped front and back plates then bent sideplates that form the box?
Tack weld them into position then weld the seams up?

[hangtime]

I like that idea, then I would only be cutting flat stock and making a couple of simple bends in the end of my vise.  At emachineshop.com you can download a simple cad program and order over the net. I had a hard time drawing the 3d image but with this 2d approach I think we have a winner!!

[demographic]

If you cut the Ys first you could tack weld them into position and then fit the exhaust and check it's got enough clearance around it, then when your sure you can weld the sideplates on.

Don't mind me by the way as I am just thinking this through myself

What welding rods/filler wire are you using?
I think I have seen some info regarding what welding rods suit the alloys that the manufacturers commonly use, I will see if I can find it for you.

[hangtime]

I need all the help I can get thinking my way through this as well. It is easy to end up staring at something and getting stuck with one idea, then someone comes along with a second idea (plates), and it all starts making sense again.
I have a lincoln 175 welder, and have yet to weld aluminum . I do have a friend who works at a marine yard and seems to have a good touch. I would be nice to have a few test runs either way.. If I am welding 6061, do I need a different rod than say 4043??

[demographic]

Although I used to work as a welder years ago I never did much aluminium either, but I have a couple of books that I am fairly sure should help out a bit.
I do know that there are a huge amount of different aluminium alloys and some are not compatable.

[KXcam22]

Hangtime,
  Your project is looking good.  Looking at those service honda photos (nice photos), the only thing I noticed was that they used "tabs" for the engine mounts.  For strength I think those should be more of a triangle shape like the stock mounts. A tab isn't very strong and puts lots of stress at the root where it's welded.  Also, Ive seen conversions where they used a round thinwall tube attached to the carb inlet to bridge a gap between the carb and the airbox boot.  It looks tacky if it's long but it almost invisible if it is 2" or less.  Hope this helps.  Cam.

[hangtime]

I agree Cam, there is one photo that shows a tab that looks to be only about 3/4 in wide. Too much load over a small area. I think I'll cut out a longer triangular piece. Unfortunately the mount on the engine cases is narrower than the frame rails so I'll have to use a spacer.

[KXcam22]

Hangtime,
  You could also dogleg them in a bit (L bend) to make up the gap rather than use a spacer, specially if you can get in close enough to tack weld them in place with the engine in (and bolted to) to hold them in the exact spot. In the end thought using a spacer is no big deal either. Cam.

[hughes]

Hey, We all need to see more photo's of this bike your putting together.

[kxs in oz]

Hi i am in australia and am also doing this conversion kx500 to 450f and have found if you get a 06 250f air box boot it will bolt straight onto the 450 air box and is lower than a 450 one so it will suit the 500 carby better all you have to do is make a adaptor to go on carby to air boot