Kawasaki experts!! Clutch and exhaust Qs

[nzspokes]

My GPZ400r has the clutch rattle at idle that Kawas seem to get. Is it worth worrying about? from what Ive read overseas you just ignore it but am happy to replace the clutch later on as funds allow our not bother. Clutch functions fine.

The attached pic is one of my mufflers, is it worth trying to debaffle it? Will it improve HP? Not really looking for more noise.

[nzspokes]

I will add the pic this time.:wacko:

[Grumph]

The rattle is actually the shock absorbing backplate. These Kawas have rubber shock absorbing inserts in the backplate rather than the more usual springs. The rubber takes a pemanent set giving a certain amount of free movement.
Many years ago I replaced the rubbers with a set of urethane inserts I made up. Worked well but probably too much work to be cost effective when the standard fix is simply to turn up the idle....

As soon as you debaffle the mufflers you're going to be asking about carburation problems......

[nzspokes]

The rattle is actually the shock absorbing backplate. These Kawas have rubber shock absorbing inserts in the backplate rather than the more usual springs. The rubber takes a pemanent set giving a certain amount of free movement.
Many years ago I replaced the rubbers with a set of urethane inserts I made up. Worked well but probably too much work to be cost effective when the standard fix is simply to turn up the idle....

As soon as you debaffle the mufflers you're going to be asking about carburation problems......

OIC. Ive not had it apart. Only get it at cold idle.

Im happy to re-jet carbs to suit if there are real gains to be had.

[F5 Dave]

Why would there be any gains? Its an 80s 400, it is what it is.

[nzspokes]

Why would there be any gains? Its an 80s 400, it is what it is.

As in they are quicker than modern 400s, yes i agree.

[F5 Dave]

what is a modern 400? do the japs still make em for the local market?, thought they had given up bikes.

[ducatilover]

If you need a clutch basket, try find if a ZZR400k one will fit, I've got a complete clutch with new linings and spare second hand linings I'll be happy to get some money stuff for? Clutch springs included ;)

Off to google.

[nzspokes]

If you need a clutch basket, try find if a ZZR400k one will fit, I've got a complete clutch with new linings and spare second hand linings I'll be happy to get some money stuff for? Clutch springs included ;)

Off to google.

Wonder if they fix the rattle useing springs?

[ducatilover]

Wonder if they fix the rattle useing springs?
Possibly? Could even be a loose hub nut on the clutch?
I can't find a parts fiche for the GPZ400 so can't compare part numbers :weep:

[FJRider]

\m happy to re-jet carbs to suit if there are real gains to be had.

Some gain with an aftermarket exaust system maybe ... with correct jetting done at the same time. Hacking the old one, usually just gives you more noise ... even with re-jetting. Single figure % of horse-power increase's ...

Make the most of what you have ... you should keep up with bigger bikes under 180 km/hr. Through the windy's ... be ahead ...

[ducatilover]

Make the most of what you have ... you should keep up with bigger bikes under 180 km/hr. Through the windy's ... be ahead ...
Not any modern ones :bleh:

[nzspokes]

Possibly? Could even be a loose hub nut on the clutch?
I can't find a parts fiche for the GPZ400 so can't compare part numbers :weep:

From the post above sounds like something to do with Rubber being used instead of springs. Lots on internet about the noise and most say just bring up the idle.

[nzspokes]

Some gain with an aftermarket exaust system maybe ... with correct jetting done at the same time. Hacking the old one, usually just gives you more noise ... even with re-jetting. Single figure % of horse-power increase's ...

Make the most of what you have ... you should keep up with bigger bikes under 180 km/hr. Through the windy's ... be ahead ...

Dont really want more noise so will ride it as it is. Will check plugs to see how she is doing at the moment.

[FJRider]

Not any modern ones :bleh:

More would depend on the rider ... more than the bike ... Unless it's a Ducati ... then you don't try. :bleh:

[ducatilover]

From the post above sounds like something to do with Rubber being used instead of springs. Lots on internet about the noise and most say just bring up the idle.
Does it quieten down if your idle is higher? What's it idling at now?


More would depend on the rider ... more than the bike ... Unless it's a Ducati ... then you don't try. :bleh:
I just go slow and fall off, so he'll thrash me :crazy:

[nzspokes]

Does it quieten down if your idle is higher? What's it idling at now?



Yes it goes away. Cold idle is about 900.

[F5 Dave]

then don't lose any sleep over it & start worrying about tyres instead.

[nzspokes]

then don't lose any sleep over it & start worrying about tyres instead.

Why would i worry about tyres? Tyres dont worry me. Ex wife worries me. :crazy:

[F5 Dave]

just they are queer sizes these days. I imagine considerably less bikes running them than even skinny 18s will mean supply may become patchy, choice already is.

[nzspokes]

just they are queer sizes these days. I imagine considerably less bikes running them than even skinny 18s will mean supply may become patchy, choice already is.

No, BT45s are in stock and will do me fine.

[Tigadee]

The attached pic is one of my mufflers, is it worth trying to debaffle it? Will it improve HP?

:facepalm: 59 horses on tap and the man wants more! Oy vey!:weird:

:buggerd:

[nzspokes]

:facepalm: 59 horses on tap and the man wants more! Oy vey!:weird:

:buggerd:

Just tuning. ;)