I picked up an 04 cbr 600rr that my friend raced last year. The last race of the season he droped a valve. I think he saved it in time for it not to destroy the motor completely. But I am at the moment getting ready to purchase a new motor to just get it going. Will an 05 motor fit in a 04 frame? I have been told it can and has been done. Im talking 04 frame and electronics and throttle bodies with a 05 motor? I have also heard that the 05 cylinder head intake ports are different. Is this true and does it make a difference?

 

Yes, the 05 motor will bolt right in. BUT you will need 05/06 ecu & wire harnessas some of the sensors are different. I also know the throttle bodies andthe airboxare different,the 04 might bolt up, but I have a hunch you'll need the correct throttle bodies to match the ecu & motor.

The Head is the biggest difference, The 05/06 Head has smaller intake ports at a slightly different angle. This gives a higher velocity and better fill allowing the motor to make more midrange HP & Torque withoutreducing top end. Yes it is better.

 

Can you use the 04 electronic's? Or can you just switch out the sensors? Can you map the FI for the 04 throttle bodys? Im also going to be throwing a 50hp wet shot at this thing too. So Im already buggeting for 2 motors. Im also running no air box and stacks on the throttle bodys. (Drag bike).

 

I don't know for sure. I know the speed sensor is different but can be switched, as is the cam pulser. That combined with custom mapping you might be able to get away with it.

If you're going to throw a 50 shot, you might want to think about upgrading the rods and pistons while your in there.

 

can those sensors be switched out with the older sensors? Speed sensor, I only really need that if I want to see my mph right or does that send the tach signal too. The engine rpm range is going to be between 10k and 16k. Before the old motor dropeda valve the bike was running 6.40's in the 1/8. and that was with a 190lb rider plus it was the stock motor, no spray,and a power commander with a bad map. If the old motor isn't messed up too bad im putting a 619 kit in it with a fresh head. SO im kinda hoping I don't really need to put in a new motor. But right now im leaning towards sticking to an 04 motor. I just had a killer deal on an 05 motor. But it sounds like it's going to be too much of a hassel. I really don't need the spray, I only weigh 150lbs in full gear. SO with weight I can take about 2 tenths off alone. I just found a controler for the spray so I think I might do a progressive to about 35 so not to gernade the motor. (in the first two weeks). Thanks for the input. If you know of any 04 600rr motors Cheap please let me know.

 

I belive you should be able to swap them, but I'm not sure... You'll still need a speed sensor because the ecu uses it for other functions as well as the speed, and it will throw a fault code it's not there. With the overbore and a fresh head (doa 5-angle valve job, and setthe squish), the 04 motor will be every bit, if not stronger that a stock 05 motor.