Wow! See-trough air scoops!

Karsten's "Flash from the Past that Flashes Past" 7/11

Personal CV

My name is Karsten Horn and I'm living in Denmark. For various reasons it is very expensive to buy Bikes and cars as a Dane due to special registration tax. I have been a motorcyclist for 18 years and have owned more than 20 bikes so far. All my bikes have been sport bikes and especially during the last 10 years I have focused on max power and superb handling. I work part-time as a motorcycle mechanic when I'm not at my real job (lieutenant commander in the Royal Danish Navy). The future will show weather I'm quitting my job in the navy and focusing 100 percent on the bike business or not.
I have made many weird bikes so far, for instance a Honda CB1100R with a GSXR 1100 engine and a Kawa ZXR7 with a FZR 1000 EXUP engine.
Years ago my friends and me decided that if we should survive as motorcyclists we better slow down on the back roads and do the knee sliding on the race tracks instead of riding like lunatics on public roads. So now my best friend rent the biggest track in Scandinavia (Anderstorp Raceway) approximately 4 times a year and that is so much fun and a very good place to test if the bike is operating the way it is supposed to.
Why I wanted a 7/11: The GSXR 1100 engine has always fascinated me due to:
- It is quite simple and easy to work on.
- It is Very light due to the oil cooling philosophy.
- It is easy to buy tuning bits for it.
- Most important of all it produces so much torque and even in a high tuning stage it has a very wide torque band.
The best way to save weight is to fit a smaller rider.

This bolt is able to stop 160 horses from stampeding. 		Even though the frame from a GSXR 1100 is much stronger than a 750 frame it is much heavier too and the frame geometry is not as aggressive as the 750 frame. The reason why I went for the 87 750 frame was quite simple, the lightest 750 ever made (179 kg dry). I was prepared to do some serious mods to the frame in order to cope with the extra horsepower and torque. I knew that a 87 GSXR 750 was famous for tank slapping and all sorts of misbehaviour when ridden hard in the Superbike series at that time. But it did not scare me, because first of all I would not be able to ride the bike so hard in the first place and secondly a friend of mine knew how to make the frame so stiff that it was working properly.The idea was born and in the following I will describe how I made the bike, what mods I have done, my experience with the bike so far and what plans I have for the future.
The Engine

The engine is a 90 GSXR 1100, originally 1127 ccm and brick head (last version with oil cooling). As I was looking for an engine characteristic as close to standard as possible a turbo configuration was out of the question due to turbo delay and power delivery and so on. I decided to go along the classical tuning track with bigger displacement, better fuel delivery and better flowing head. My best friend (the bloke who owns the bike store) had used the 1100 engine in his Nico Bakker frame and I was able to get a lot of valuable knowledge from him.
40mm Mikuni flatslides... we love a deep throat once in a while.

These are the engine mods I have done so far:

- Wiseco pistons bored to 1216 ccm and compression ratio 12.2/1 (we have had a lot of problems with the Wiseco pistons due to the fact that they would shrink after a short while because of wrong bore tolerances and the fact that the piston is almost 33 percent heavier than stock.)

- Fully race flowed head from a 88 1100 engine (the one with adjustment screws for the valve clearance)

- Balanced and slightly lightened crankshaft from a GSX 1100F engine together with clutch assembly (the weak spot in a tuned GSXR 1100 engine is the crankshaft. When producing more than 160 HP on the rear wheel they tend to break in two pieces. So far my friend have broken 3 crankshafts, all broken at the exactly same spot. The GSX 1100F crankshaft seems to be stronger due to different sprocket layout between crankshaft and clutch.)

- Extra oil cooler connected to the oil lines cooling the head. Oil cooler is located under seat and will cool the oil an extra 7 to 10 degree Celsius. (The oil cooler is only mounted when riding in southern Europe. During summer time in Denmark the oil temperature seldom gets above 75-80 degrees. Ideal oil temperature is 75 degrees, for each 10 degrees more; the engine will loose 3-5 percent of power.)

- 40 mm Mikuni Flatslides in order to feed the beast (I know that some people don't like the Flatslides but for me they are essential due to many factors, most important for me is the instant trottle response and the fact that they make the re-jetting a very easy task not to mention the performance gain.)

 - Dyno ignition coils - Yoshi engine covers

- Yoshi RS 3 race only Duplex Titanium exhaust system (Total weight 3.1 kg :-) )

- Standard ignition box and standard RPM limited at 11.800 RPM's. (Have tried V&H Power Pack but did not gain any power at all so it was thrown away. Have tried ignition Advancers as well and my experience is that it won't work with a tuned engine like mine but an almost stock engine might gain a little mid-range.)