OzVMX Forum

Clubroom => Tech Talk => Topic started by: ralph311 on December 02, 2014, 02:44:30 pm

Title: 39mm PWK Keihin legal in pre-85??
Post by: ralph311 on December 02, 2014, 02:44:30 pm

Hello all,

I've searched quite a bit and been unable to find an unambiguous answer - Is a Keihin PWK 39mm carb legal in the pre '85 class on a 1984 Honda CR500? No arguments please and if you aren't sure let's both wait for someone who is.  ;)

Cheers.

Title: Re: 39mm PWK Keihin legal in pre-85??
Post by: Nathan S on December 02, 2014, 03:01:39 pm

PWKs didn't come out until the second half of the 1980s, so they fail the "period" test for Pre-85 bikes.

AFAIK, the only flatslides available before 1985 are the crappy, early Mikunis, and the Lectron.
Lectrons have their own little cult, and seem to work very well if you can be bothered to learn them and gather the required number of needles.
The pre-85 Mikuni flatslides aren't great - I would choose a Mikuni roundslide as my first preference.

Title: Re: 39mm PWK Keihin legal in pre-85??
Post by: ralph311 on December 02, 2014, 04:32:48 pm

Thanks Nathan  :)

Title: Re: 39mm PWK Keihin legal in pre-85??
Post by: John Orchard on December 02, 2014, 04:44:33 pm

Ha I was just thinking the same thing a couple of minutes ago :-)

If the PWK is no-go, what about the PJ ?

Title: Re: 39mm PWK Keihin legal in pre-85??
Post by: Nathan S on December 02, 2014, 04:53:17 pm

PJ is barely worth it's weight in scrap metal. Horrible carburettor for anything that's not being road raced. Mikuni VM is a much better carb for a dirt bike.

They first came out in 85 or 86. I'm 99.99% sure they're not pre-85 legal.

Title: Re: 39mm PWK Keihin legal in pre-85??
Post by: bigk on December 02, 2014, 05:03:53 pm

Don't the MOMS state any flat slide carb? This would allow a Mikuni TMX as well as TM as it is a flat slide whereas the Keihin PWK is a crescent shaped slide.
K