Board index   FAQ   Search  
Register  Login
Board index VRRA Racing Forum Technically Speaking:

Rules clarification for an EX500

Bike preparation, class eligibility, technical questions.

Moderator: Michael Vinten

Rules clarification for an EX500

Postby Brian Stevenson » Sat Sep 10, 2022 5:56 am

Posting for a friend who runs a Ex500 in WERA.

He wants to do a few VRRA events next year - Mosport and Calabogie - and has a Kawasaki EX500 that has been sleeved to 590cc.

It’s nativity a P4 Light bike as it would be classed as a Four Stroke Twin under 650cc. However in the rule book it says “ Cylinders may be overboard to give a maximum engine displacement of 5% over each engine limit”.

What is the engine limit that is being referred to? He interperates that as 650cc (which is the maximum for four stroke twins) so 590cc for his bike is fine. I guess +5% of that engine limit would be 682cc so he’s well within that.

When I originally read that I assumed that the engine limit referred to was the bikes original 500cc displacement but I don’t think I’m right.

I had him reach out to Michael but I’m now curious myself. Anyone have any insight or been through this themselves?
Brian Stevenson
VRRA Member
Posts: 314
Joined: Sat May 05, 2012 3:28 pm
Location: Whitby, ON

Re: Rules clarification for an EX500

Postby Michael Vinten » Thu Sep 15, 2022 7:11 pm

I replied to Brian's friend directly but should have copied the reply here.

Engine limit refers to the cc of each engine type, thus four stroke twins are allowed up to 650cc no matter what their original size was. The 5% is in all classes because some engines are at the class limit stock and would not be allowed to use factory overbores when worn.
Mike #19
Michael Vinten
Tech Committee
Posts: 1976
Joined: Tue Feb 04, 2003 8:47 pm

Return to Technically Speaking:

Who is online

Users browsing this forum: No registered users and 2 guests