GSXR250R (GJ73A) Race Bike Build

The inner tube bits shouldn't come into contact with petrol where they are, but I'll try and find something that is a better fit. I was up at my friends workshop today and checked out the airbox on his RS125 which uses the bottom of the tank as the lid. Seeing the design up close has given me renewed hope of a fully enclosed setup again, lots more head scratching to come...!

 

Hi everyone, its been ages since any updates but pleased to report I am still alive and so is the bike! I raced at the ASBK support races at Symmons Plains a couple weeks ago and it was a successful first outing there on the 250. The track is basically 2 drag strips linked by a couple corners but was more fun that I thought it would be on the little bike. With only 3 races I didn't get a whole lot of track time and my times only came down by less than a sec from qualifying, it was quite different to racing a 600 there, normally where I was hard on the brakes I still had the little 250 throttle pinned and was flat on the tank! I had a great battle in race 2 against an MC22, the Honda had a slight top speed advantage but my bike was fantastic on the brakes and with it's smoother power delivery I could use 2nd gear out of the hairpin which helped me make a move on the last lap and stay in front to the finish line.

I put a lot of work into the bikes appearance before the round, the fully enclosed bellypan isn't a perfect fit but it's structurally sound and makes the bike fully race-legal finally. I decided to go with yellow and black rather than re-paint the whole bike, used my spare petrol tank, painted over all the multi-colours with black and put the mandatory green number backgrounds on. It came up pretty good, even though it doesn't match my leathers I think I will stick with this colour scheme for a while



I've also spent many, many nights making the custom airbox. I modeled it out of floral bricks to get the basic shape, then covered it with fibreglass and filler. It has to hug the contour of the frame and tank perfectly as there is very little clearance for the carbs, so it's been a long slow process to get it perfect. It's now done and I have made the mould, will hopefully have the final part made soon. Here is a pic of the plug when it was close to completion.