The purpose of the 60 HP Fuel Injected KLR 650 is to demonstrate that the KLR650 is more than able to compete, power wise, with its more modern brethren.
The objective was to build an engine that will produce the most “reliable” HP possible, be fairly fuel efficient but still use 87 octane fuel. That I believe we have achieved.
Current setup for the 60 hp KLR 650
- Flow ported cylinder head with 1 mm oversize intake and exhaust vales
- Stock valve springs
- Stock Shim buckets
- Adjustable Cam Gear
- Stage one Hot cam. Degreed to specific lobe centers
- Cometic head gasket
- 685cc forged CP piston with 10:1 static compression ratio
- Stock Connecting Rod
- Dirt Digger Clutch Kit
- FMF Powercore 4 with powerbomb header
- Link G4 Atom Engine Management System with builtin barometric pressure sensor.
- Custom wiring harness
- BMW Motorcycle 44 mm throttle body
- 550 cc Denso fuel injector
- Stock Crank position sensor on 12 tooth modified rotor
- Suzuki GSX 750 5 volt three wire Hall Affect Cam Position Sensor to pickup cam position on intake cam.
- Modified Valve cover to accommodate cam position sensor.
- 2012 Honda Shadow Aero 750 fuel pump assembly
- Custom made fuel shutoff valve block
On the dyno we quickly realized that the stock clutch was not going to hold up the power. We might have gotten away with just installing stronger clutch springs but we opted to install a complete Dirt Digger Clutch Kit
Note: Other than the Dirt Digger Clutch Kit and the PW oil feed mods, nothing in the bottom end, from the connecting rod down, was modified
Other than for the EFI system we believe that the amount of modifications was kept relatively low.
Can this KLR650 engine make more power?
For all the test so far we have been using regular 87 octane gas. Peak ignition timing at 27 degrees only. This we have done to show that the bike can basically be ridden in any place in the USA.
We believe that changing the fuel to 93 octane premium gas and increase the ignition timing to compensate, this KLR should be able to produce an additional 6 – 8 hp.
Although we used a piston with a calculated 10:1 compression ratio, final measured static compression ration came in at 9.8:1. This is because we de-shrouded the head around the valve seat area after we installed 1 mm oversize valves and did not deck the head to compensate. This was done on purpose.
Test Riding the EFI KLR 650
With a wide power band and lots of torque the bike is very smooth and easy to ride. Acceleration is a blast and the bike will pull hard all the way to 8200 rpm. An average of 46 – 48 MPG is achieved in cruise and light throttle loads. Getting too excited with full throttle pulls will see the fuel consumption go south very quickly. 100 MPH comes up much quicker than expected. The front end comes up very quickly under hard acceleration in first gear.
Engine temperature match those of a stock KLR when riding the bike in stop and go traffic on a hot and muggy summers day.
Anything above an AFR of +/_ 13:1 and the engine will begin to hesitate under full loads. This is at least one full point richer than our small port carbureted KLR. We believe that swirl might have something to do with it.
Must I have Fuel Injection to make this kind of power
Although we have not tested our self, we believe that it is possible to come close to the same power using an appropriately sized carburetor. It will have to be something in the 44 – 46 mm range. Controlling ignition timing would obviously become a point of contention