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ZX12R engine run backwards
Hellfire - 27/10/17 at 11:05 AM

So... just about finished rebuilding the rear end of the Indy after a slight accident last year where the Indy was spun 180 degrees and travelled backwards for a short while with the engine still running but without the clutch depressed.

The starter motor was obviously destroyed but having replaced it with another starter motor, the engine still failed to start, although the starter motor did 'clunk'. The spark plugs have been removed and the cylinders lubricated but the starter motor won't turn the engine

The battery has been kept charged with an optimate, so should be in reasonable condition.

What are the chances of the engine being seriously damaged by travelling backwards?

Phil


nick205 - 27/10/17 at 11:24 AM

Can you turn the engine over by hand?

How's the oil pump driven - i.e. would it also have been driven backwards if the engine was turning over backwards?


adithorp - 27/10/17 at 12:04 PM

It's possible that it's done other damage but it'd be something like a bent rod to stop it turning and that seems unlikely. I'd try it with some jump leads from another battery first just to rule the battery out before jumping to any conclusions.

When you say plugs out and lubed... have you still got them out? It'll need spinning over with them out to clear and excess you put in and prevent it hydro- locking.

PS. I had been wondering if you'd fallen out with us as not seen a post for a while.

[Edited on 27/10/17 by adithorp]


CosKev3 - 27/10/17 at 04:27 PM

Jack it up and stick it in gear,then see if the engine turns over by turning the rear wheels.

If not you have broken something that's jamming the engine/transmission.


ReMan - 27/10/17 at 06:42 PM

I'd think unlikely.
Can you not "bump" the engine over pushing it in gear?
I'd suspect its lightly stuck, (not fully seized) from sitting


motorcycle_mayhem - 28/10/17 at 08:29 AM

Turn it over by hand, as has been said.

The Suzuki GSXR cam drive architecture can suffer if abused in this way (or it has with me), I have no idea if the Kawasaki suffers though.


Hellfire - 28/10/17 at 05:04 PM

The back end is already jacked up so we'll try turning the engine using the rear wheels. Hopefully it is just lightly stuck......

Yes, the spark plugs are still out. It's been stood in the garage for 16 months, so the cylinders have been well lubricated.

On the plus side, it gave us the chance to replace the rear end and completely alter the geometry to improve handling.

Thanks for all the advice! I'll post an update next week

Phil

[Edited on 28-10-17 by Hellfire]


Hellfire - 31/10/17 at 08:50 PM

Rear wheels wouldn't turn the engine, it's a LSD. All that happened was the opposite wheel turned in reverse.... So tried it on the starter button and the engine turned over. Put the spark plugs back in and she fired up first time. Just got a few small jobs to finish and she'll be back on the road!

Phil


roadrunner - 1/11/17 at 07:00 AM

Great news 👍