FZRSupport: the FZROnline Archive

ok... so I hear the yzf engine is a bolt in if you use the yzf harness... what else is there to it? I hear there's a 15 hp gain? correct? I'm looking to purchase an entire bike to make sure I have EVERYTHING to do this project because I'd also like to do the yzf swingarm and wheel swap at the same time. any info on this is greatly appreciated.

a few actual questions...

are the gear ratios the same on both engines?

will the exhaust on my fzr still work with the yzf engine?

what year yzf's will work?

I just put a YZF600 engine into a 400 frame.

I think you have to use the FZR exhaust. Something about the YZF exhaust hanging too low, but that might only be in the 400 frame. I'm not there yet, so I'm not sure.

Keep us up to date on your project. It's supposed to yield a 10-15 HP gain over the FZR600 motor.

wow... not too much help here I thought this place was loaded with fzr info

kingcobra wrote:wow... not too much help here I thought this place was loaded with fzr info

I was hoping that someone who has done the swap would have chimed in by now. I've haven't done the swap but as I understand it, here is what you need.

YZF600 engine - any year
YZF600 carbs - year needs to match the electrical system
Full YZF600 electrical system - wire harness, ecu, vr, coils, starter celenoid, and maybe the relays
YZF600 swingarm and rear wheel to make it easier - the sprocket offset is an issue if you don't, but not a huge one

Parts I'm not sure about

Air box - if it needs to be modified or not
Exhaust system - the FZR system will fit no problem. The issue is clearance and I don't know which one is better to use. There was also something mentioned about using the FZR oil pan to help with clearance issues.
Radiator and cooling hoses - the colling tubes are routed differently.
Might need to fabricate a bracket to help hole the engine in place.

Might be missing something here, so hopefully someone will make corrections for me. The gear rations are also different and the sprockets are different as well.

What you get is 10-15 more hp and a 17" rear wheel that will take a 160-170 tire for about $1000. If your planning on doing this, buying a dooner bike is the best bet.

Hope this helps.

YZF 600
1st 37/13 (2.846)
2nd 37/19 (1.947)
3rd 34/22 (1.545)
4th 28/21 (1.333)
5th 25/21 (1.190)
6th 29/27 (1.074)
Primary Reduction Ratio 82/48 (1.708)
Secondary Reduction Ratio 47/15 (3.133)


FZR 600 Gear ratio
1 - 2.846
2 - 1.947
3 - 1.55
4 - 1.333
5 - 1.192
6 - 1.111
Primary reduction ratio 1.708
Secondary reduction ratio 3


they are nearly identical

a bracket to hold the engine in place? huh?

kingcobra wrote:a bracket to hold the engine in place? huh?

Like I said, I'm not entirly sure on that one. The YZF engine has two bolt holes in the cylinder head. I've seen people make a braket the bolts to there then to the down tube spot. Could just be for added support though.

That's all it is. I do believe the lower cradle arms still attach at the same place that the FZR does. I'm not 100% certain, but I've held it up and it looks to be the same.

cad600 wrote:

kingcobra wrote:a bracket to hold the engine in place? huh?

Like I said, I'm not entirly sure on that one. The YZF engine has two bolt holes in the cylinder head. I've seen people make a braket the bolts to there then to the down tube spot. Could just be for added support though.

I believe you do need to 'fab' a bracket as the head mouting points are different, but only by a little.

I put fab in quote becuase I am 99% sure its a rectangle with a few bolt holes in it and no bending etc required

It does not match up to the same bolt hole that is down below on the cradles, so some type of fabrication will have to take place.

I think some zip ties would do the trick!

I'd like to see pics of one installed... anyone?

so... we know it can be done yet no one has pics of it done? that sucks come on guys... this is THE fzr info hotspot!!!

kingcobra wrote:so... we know it can be done yet no one has pics of it done? that sucks come on guys... this is THE fzr info hotspot!!!

I have no pics...

but thatkids bike has it, so look at his pics