www.zxrworld.co.uk

Hello all

Can someone out of all you knowledgeable and well informed crowd please clarify what you can and cant do to your 400 for supersport 400 and for streetstock 400. I know this is tedious but I'm looking at racing next year with NGRRC and trying to work out in which to go. My bike is standard engine but with all the road gubbins stripped off but as its an old written off bike I have no V5 so cant MOT obviously. Does this eliminate me from streetstocks? If I go formula 400, I may buy another bike as mine will be well down on power etc. Do they allow a 0.5 overbore? If someone can list for each class does and donts you'll save me a fortune. The ACU handbook is crap!

Hello Max,

We do Streetstocks400 and F400 with North Glos

A SS400 bike :
- requires a V5 and current M.O.T. certificate when the bike is scrutineered.
- the bike must not exceed 98Db (which severely limits the effectiveness of any tuning headwork once the exhaust is bunged up)
- needs to start on the button & the horn must work.
- You must use the original wheels.
- Number plate to be fitted too !

An F400 can :
- have the generator and starter motor removed ( bump start required ) which loses a few KG plus a couple more BHP by not running the generator
- Use light wheels (Dymags etc)
- Use a full race exhaust system ( lots more power than a standard exhaust)

Both Formulas allow you to use different suspension units or rework the standard stuff, you can fit race bodywork and the belly pan must be closed and able to contain the fluid contents of the engine. You can use the standard bodywork actually, just fit a catch tank in the belly pan.
You need a sharks fin ahead of the rear sprocket, and must wire lock the sump bolt, oil filler cap and clamp a jubilee clip to the oil filter and then wire lock the jubilee clip to the bike.
The steering lock must be sufficient to prevent your hands / thumbs being trapped by the bars against the tank, and generally the head bearings, swinging arm bearings, wheel bearings must be serviceable. Bike should be clean, free of leaks and have water in the cooling system, not coolant (slippery).
The bike needs to have two front brakes lines (one for each caliper),best to bin the standard rubber lines anyway as they bulge and limit your braking once the fluid gets hot.

EMRA run a "Roadstocks" class - They say the bike must be road legal, but you can have 105db exhaust system (?) and a V5 & working horn and rear brake light.
BEMSEE allow 0.5mm overbore in their F400 class
Thundersport GB allow 450cc in their Junior Powerbikes.

I hope this helps, PM me if you have any other questions

http://www.blackandblueracing.co.uk

Mark400 u r indeed a star. That clarifies loadsa stuff. Somebits n bobs ive already done such as the brakelines and bodywork but I know what I need to get doing over the winter. Just to check, NGRRC dont allow 0.5 overbore? (just in case I decide to look for a tuned bike over winter)

Thanks again bud

as far as im aware, f400 countrywide allow manufacturers overbore limit, which is zxr 0.5, fzr +1, hondas nowt.
bemsee is the only club to allow +1, and the mgp (altho mixed reports of this).

Just to confirm the 400 rules for the Manx GP


Anything goes.................there are no 400 specfic rules................................you are allowed to overbore to the manufacturers maximum................in the case of a ZXR that means 0.5

You must have all the normal safety stuff done lockwiring etc and you must be within the noise limits and use unleaded fuel.

Max fuel capacity is 24 liters.....................and on a ZXR 400 for a 4 lap race a 24 liter tank is no advanatge may as well stick with the orginal one.

If anyone needs further help or guidance about the Manx GP and rules..................just ask

Hi again - You need page 285 of the handbook - Which states that you can overbore to the manufacturers reccomended rebore size - So the biggest size Kawasaki reccomend (and have a part number for) is 0.5mm oversize as Jake & Cargo correctly say.

Bemsee do indeed allow 1mm over,but no one else allow it.

The ACU noise limit is 105Db at 8000 rpm for a zxr400.

I hope you race with NG incidentally, the format is excellent and the club is friendly and well run.

http://www.acu.org.uk/uploaded/document ... K_2009.pdf