FZX 700 engine into an FZR 600

[Deadeye512xr]

So fellow fizzer enthusiasts... here's my situation, I have my 1992 Yamaha FZR 600 and last summer 2nd gear went out on my way home from work . So I was thinking of ripping into the motor and doing a basic rebuild and fixing the shift fork or drum responsible and just generally freshen it up. But I also have a 1986 Yamaha FZX 700 Fazer that used to be a drag bike with a kerker 4-1 full exhaust. I love the fzr's handling but the five valve 700 motor on the fazer and how rambunctious and mean it is compared to the fzr. So I want to put the 700 motor into the fzr but I'm not sure if it will work or not I could use somebody who knows of any difference in these engines except the obvious ones.

[willandrip]

That's a US only model produced for only 2 years 86/87. (This means when spares are required for that then they may be scarce)
Not available in UK...we got a 750...the full power version (+ 10bhp) It was not that popular.

Anyhow : you have the item infront of you.
I doubt anyone has done the swap previous....It's a bit retrograde for a sportsbike.
Certainly the electrics will require swapping/modification and I doubt the airbox that goes with the 700 carbs will fit ...then that leaves the tank and cover to modify.

Shame to strip a working bike to fix an engine fault on another.

Personally I would source a good used engine for your Fzr.
Cost of rebuild components for your original make the repair economically unviable.
It's a barrels off and crankcase split job.
Genuine gaskets aren't cheap (head /base)...Athena kit may suffice for others...a new camchain would be fitted when split.

It is normally the engagement dogs that are damaged on 2nd gear failures...they can be undercut and reused but new replacements are more viable (time/cost factor)..If you do this then certainly replace a worn fork if found.
I would replace the dedent assy and gear selector with an upgraded version once this amount of time/ money has been spent

You now will begin to understand why these engines are replaced by another complete 600 unit by 95% of owners.

Lots of Fzr 600 units are still run with the failed 2nd gear...short shifting and using the upper gears gets as much performance as required for many riders. Every take off does not have to be a traffic light G.P.

[Deadeye512xr]

I want to put an fzr 1000 motor into the fazer because I love that bike too much to tear it apart for parts but that's a separate project I justhink thought since the engines are pretty much the same it might work and Imy going to swap in an fzr 1000 into the fazer down the road anyway so I thought I might as well put this awesome 700 engine to use and then I wouldn't have to buy two engines (1000 genesis and thenot a used fzr 600 engine) and then my 700 would just be laying around.

[willandrip]

I see the logic behind your thinking on the multiple engine buying scenario....

I just don't see the logic of putting a sportsbike engine into a street bike and then putting the streetbike engine into a different sportsbike...The engine characteristics are very different....no Fzr engine likes to lug about and the Fz700 has a lot of low down grunt .

Good luck with your projects.