fzr needing new engine

[sean61]

I'm looking for a project bike to work on over the winter months and there doesn't seem to be many bargains to be had here in Ireland. I've just found a 93 fzr 400 that needs an engine. The rest of the bike looks clean and there are a few cheap bikes online that may be suitable engine donors. Will any year 400 engine fit or were there different models? The ad for the bike is in the link below

http://touch.adverts.ie/car/yamaha/othe ... ne/4190845

[Evilchicken0]

It's a 1989 / 90 FZR400RR 3TJ - the 94 is probably when the bike came into the UK.
As for a donor engine a FZR600R Foxeye is the cheapest option the ThunderCat engine is a bit more expensive.

For the conversion you need the 600 engine, downpipes, (foxeye) carbs, airbox and a pair of top mount plates (available on ebay). It's nice to have the (foxeye) CDI and loom. You remove the spacers between the frame and engine then you can fit the top mount plates in to istall the engine. Foxeye carbs don't have the T'Cat tps so they fit, the 600 loom has one terminal (I can't remember which) that needs to be closed and of course it fit's up to the CDI. Then cut and shut the 600 and 400 airboxes the 600 doesn't fit under the 400 tank and the 600 tank doesn't fit the 400 frame. The radiator needs the bottom mount stays lenghtened to accommodate the downpipes and you can turn the righthand hose upside down.
The 400 / 600 crankcases are common which is what makes this conversion so easy. The ThunderCat has nikasil barrels
so expect to pay +£100 for thst engine but outwardly they're the same.

The 400 engines are different - the earlier engines have 3 fake cooling fins on the head and don't have a top mounting point the 3TJ engines look smoother. The earlier frame has two rails that pick up mounts at the front of gear box whereas the 3TJ uses the engine as a stressed member. The problem is all of them are stamped 1WG.

600 euros is ok for the bike as it stands but remember you won't be able to sell off the engine for spares.

[DonTZ125]

If you use a 4JH or 4TV engine, you MUST use a TCI from either of those bikes. The trigger pattern on the crank wheel is completely different. An FZR400 or 600 TCI just won't work.

[Evilchicken0]

I think the 3TJ ignition is different to the 1WG. The flywheel is outside the generator and the cover is, just a cover on the TJ.
The 1WG engine is similar to the 3HE 600 - the 3TJ is similar to the 600R (4JH) and T'Cat (4TV). The T'Cat CDI has a circuit for the Throttle Position Sensor which is attached to the T'Cat carbs and hits the 3TJ frame. If you remove it the CDI returns a fault (the rev counter constantly flicks to 8k rpm) so it's best to use the 600R (4JH) carbs and CDI.

[pefrey]

Here's a link for stuffing a Thundercat motor into a 3TJ.

http://www.400greybike.com/forum/viewto ... =37&t=4143

[sean61]

I didn't have time to view the bike all week as I was working and the seller txt me earlier to say it's sold. A guy i know had an engine that had broken the timing chain and might have been suitable for parts but I guess I'll never know now!

[Evilchicken0]

Cheer up, if the cam chain broke chances are the valves hit the pistons anyway.