1wg engine swap

[andy83]

Hi all i have searched but cant find this anywhere. I have a 86 fzr400 and want to swap the engine for a 600. in this months practical sportsbike there is a fz600. the artical says its the same frame and size as my bike but with a 600 engine fitted as standard and that a xj600s engine bolts straight in with the 400 carbs. has anyone else heard anything about this as it sounds far to easy to me. many thanks andy.

[Evilchicken0]

They're wrong. They mean the FZ400R, it's the model before yours and has a square section steel frame.
The good news is that you can use the FZR600 3HE, it should bolt in and you don't need any frame plates. You'll need the 3HE downpipes and although not essential it would be best to get the carbs and CDI (the carbs will be jetted for the engine and the CDI will have right red line). The airbox should be the same as the 400 but because the 600 is slightly taller it moves the airbox up a bit so be ready to elongate the fuel tank shroud bolt holes to accomodate it. Coils are sometimes reported to be a lower capacity on the 400 so maybe a pair of 600 ones to make sure.
You can change the clocks for 600 ones so you get a MPH speedo and correct redline on the rev counter if you like
Collect the bits and you should be able to get it done in a weekend

[hunter]

Yep what evil said.

[andy83]

Thanks all i will look into it. also when i checked the peformance of the fz600 its worse than the 400. cheers

[Evilchicken0]

The FZ600 is deceptive it put out about 60-70 bhp but had a lot more torque than a 400, it was power banded too which came in at 90 in top. You could pull a ton with a pillion. It had a 16" wheel so it steered quickly, it won the best handling bike for its year even against the DB1 Bimota NSR400 and vfr500 and remember this was when tyres were all cross ply. There was a magazine article that said it was the fastest thing on the road point to point beating the VFR750.
They're the air cooled bike of choice for racing (in their class) too.

[barryfzr]

I have both a 1986 fzr400 1wg genesis with a fzr6003he motor in and a 1987 fzr400 2tk (same frame) with a thundercat motor in. Both slot in easy just a bit fiddly with exhaust and airbox. Go for it dude!

(had to get the thundercat jetted to breathe properly mind)

[Wraith]

There are a couple of mods that can be done for the airbox.

Where the snorkles go in the airbox, carefully cut around them so that they are free to move, with the snorkles loose refit the bottom of the airbox to the engine.

Put the top of the airbox on but do not screw it down.

Now place a piece of corragated cardboard on the top and fit the tank cover, this will push the airbox down enough to give a little space.

Take the tank cover off and carefully remove the top of the air box.

Where the snorkles come through the airbox seal around thesnorles where you cut them out with Silicone.

It is beset to leave this to set atleast overnight.

Then just reasemble as normal.

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Some people just cut around where the 2 halves of the airbox join and put Gaffertape around to join them (Bit of a bodge job in my opinion)

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I'm in the process of building another one, however this one is having a Thundercat Tank fitted as the outline of the bottom of the tank follows the lines of the frame perfectly.

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There is one point that people have forgotten to mention

The 3HE has an oil cooler fitted, now some people run the bike without one but it is advisable to fit one.

It does not have to be one from a 3HE as you will have to make mounts anyways.

[Evilchicken0]

I think its only one year of 3he that had an oil cooler - they used that one in the greybike magazine when they swapped a 600 into a 3en2

[hunter]

And that's the very same motor thati have waiting to be stripped,
To become a 660.

[barryfzr]

yep only the 1989 3he motor had an oil cooler..so I'd advise a later one..or better still a thundercat one ;o)

No engine mounting brackets will need to be made the slot straight in