Z500 for 500A/c class

[John Warwick]

Just got a Kawasaki Z500 for tha A/c class for next year any information on tuning/ mods would be greatly appreciated

[Nige Collier]

I no nothing about Z 500's but I like your style  there is one that's already being raced in the class, cant think of his name though?

[Rob Wittey]

I dynoed one a while back that was one of the original 500 cup bikes, a baby zed with 6 speed box and a few more revs, wondered at the time if it'd be competitive

[Andrew Widdowson]

Andy Mahon is the other Z500 Willridge...

[Nick Robinson]

Wasn't there a white one knocking about as well?

A tidy looking thing with Astralites?

[Andy Guy]

Rob, having dyno'd the bike, what sort of performance were you looking at?

[Rob Wittey]

Forgot to look it up today will check next week (though this was essentially a std bike)

[John Warwick]

The weight of the thing is the main issue    Was there any frames they were put in that’s available? Looking for about 55bhp out of it which should be easily available with reliably.

[Nige Collier]

The weight of the thing is the main issue    Was there any frames they were put in that’s available? Looking for about 55bhp out of it which should be easily available with reliably.

weight was the issue with the XS but the Z engine should be good for tuning unlike the doo doo XS lump

[Robin Webster]

They ran this engine in a Bimota chassis in period..

Robin 

[Andy Guy]

That would be the KB2. Unfortunately it was a gpz550 unit and not z500. The KB1 was 900.

[Andy Mahon]

Hi John, I've got the Willridge Z500. We chatted a couple of years back about it.
It was originally built in 1981, and featured in Motorcycle Mechanics March 1982, to show how much it cost to build a "rapid and competitive racer".
Problem, as has already been mentioned, is they are heavy.
Mine has a special one-off frame, yokes and swinging arm, but the rest was original Kwak.
I've upgraded the rear shocks and have now fitted lighter Dymags. It's been ported and breathed on, with Yoshi cams, and gives out about mid-50's at rear wheel.

[John Warwick]

Looking at going the 400 bottom end with the gpz550 top end gives 498cc and the 550 gives about 60bhp so should be able to get around that I think . Running spoked wheels with fairing in green of course 🙄 using the 400 down pipes as smaller than the 550 so should increase gas flow 34 mm cv carbs  all on the cheap as usual 

[Rob Wittey]

Looking at graphs it made just under 45hp with std exhaust and dyna s ignition

[Andy Guy]

Seem to recall a 500 kawasaki engine installed in a Rickman metisse frame. Anyone else recall it or just a figment of my imagination.

Manfred Rau did a copy of the egli frame for the z500. There's a couple of pictures on the net.