Rule change submissions close 1 March 2016 - be in to win.

[TZ350]

Back to the 24mm carb equivalent thing. This is my EFI throttle body. The bellmouth and throttle spigot onto the rotary valve cover which has the 24mm equivalent choke or 452mm2 area machined into it.

The present rule leaves anything that is not a standard motorcycle slide carburettor in a grey place.

My suggestion.

An edited version of Grumphs suggestion.

""Two stroke engines may be used to a maximum size including rebores of 110cc and two stroke air-cooled engines to a maximum size including rebores of 130.5cc.

Providing that, at some point in the inlet tract(s) between atmosphere and crankcase or barrel, the inlet tract(s) shall not exceed an area of 452mm2.

For the purposes of measurement, EFI throttle body idle circuit if any and carburettor air bleed jets and orifices shall be ignored.

Two strokes of 104cc or less are unrestricted in the inlet tract.""

Ok not perfect, but it tries to better define 24mm equivalent (452mm2) and allow for EFI and pumper and other carbs with a butterfly throttle plate.

[kel]

Buying bits from Europe seems to be a bit of a cause for concern. What about FI from Taiwan or Lectron carbs from the USA or Honda RS125 chassis' from Oz?

The concern is based on the premise of buckets being "non competition engines". The rules were written before such times that you could buy over the counter performance parts for your non competition engine (and we are not JUST talking cylinders). If everyone is so OK with full on little race bikes built with over the counter performance parts then lets go full open as Rich has suggested.
Not sure why you keep harping on about "axe to grind".

[Grumph]

Works for me. Now do what i can't do and print out the existing regs and work out what it's going to replace or change. And the rule numbering.

remember that the finished remit has to make sense in terms of what's in the book now and how it has to change.
Also write a short justification to go with the remit - then find a club to submit it.....

That's if the restrictions are to stay at all.

[TZ350]

Not sure why you keep harping on about "axe to grind".

An ax to grind.

[TZ350]

Current MNZ rule 24.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted. There shall be no restriction on the make, type or design of carburettor, ignition, exhaust, piston, cam, valve springs or cooling system except for class eligibility. All engines must be normally aspirated except F4 4 stroke engines of less than 100cc capacity, which may be turbo or supercharged. F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm carburettor, F5 4 stroke engines over 53cc are restricted to carburetion equivalent to a single 20mm carburettor.

Works for me, print out the existing regs and work out what it's going to replace or change. Remember that the finished remit has to make sense in terms of what's in the book now and how it has to change.

Proposed MNZ rule 24.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted. There shall be no restriction on the make, type or design of carburettor, ignition, exhaust, piston, cam, valve springs or cooling system except for class eligibility. All engines must be normally aspirated except F4 4 stroke engines of less than 100cc capacity, which may be turbo or supercharged. F4 2 stroke engines over 104cc at some point in the inlet tract(s) between atmosphere and crankcase or barrel, the inlet tract(s) shall not exceed an area of 452mm2 in total. For the purposes of measurement, EFI throttle body idle air circuit if any and carburettor air bleed jets and orifices shall be ignored. F5 4 stroke engines over 53cc are restricted to carburetion equivalent to a single 20mm carburettor.

PS I have just realised I have used the 2014 version of rule 24.2 so a little out of date but you get the idea.

[husaberg]

Current MNZ rule 24.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted. There shall be no restriction on the make, type or design of carburettor, ignition, exhaust, piston, cam, valve springs or cooling system except for class eligibility. All engines must be normally aspirated except F4 4 stroke engines of less than 100cc capacity, which may be turbo or supercharged. F4 2 stroke engines over 104cc are restricted to carburation equivalent to a single 24mm carburettor, F5 4 stroke engines over 53cc are restricted to carburetion equivalent to a single 20mm carburettor.



Proposed MNZ rule 24.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted. There shall be no restriction on the make, type or design of carburettor, ignition, exhaust, piston, cam, valve springs or cooling system except for class eligibility. All engines must be normally aspirated except F4 4 stroke engines of less than 100cc capacity, which may be turbo or supercharged. F4 2 stroke engines over 104cc at some point in the inlet tract(s) between atmosphere and crankcase or barrel, the inlet tract(s) shall not exceed an area of 452mm2 in total. For the purposes of measurement, EFI throttle body idle air circuit if any and carburettor air bleed jets and orifices shall be ignored. F5 4 stroke engines over 53cc are restricted to carburetion equivalent to a single 20mm carburettor.

if you intend of reviewing the whole portion the S needs to be clarified.

[TZ350]

Origins of the English idiom "an axe to grind"

[TZ350]

if you intend of reviewing the whole portion the S needs to be clarified.

Which "S" please explain.

[husaberg]

Origins of the English idiom "an axe to grind"

Note the term is normally pointed at people that are not that sharp.

Which "S" please explain.

Current MNZ rule 24.2 Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart motors and transmission parts are not permitted

[TZ350]

Thanks.......

[gav]

My only issue with that change is no "newbie" looking at racing a Suzuki GP125 or a twin 125 2 stroke is going to be able to make sense of 452mm2 where at least a 24mm carb did maybe?

[husaberg]

My only issue with that change is no "newbie" looking at racing a Suzuki GP125 or a twin 125 2 stroke is going to be able to make sense of 452mm2 where at least a 24mm carb did maybe?

the AMA at Daytona used a plug that was pushed into the carb intake track, pretty simple stuff.

[Bert]

My only issue with that change is no "newbie" looking at racing a Suzuki GP125 or a twin 125 2 stroke is going to be able to make sense of 452mm2 where at least a 24mm carb did maybe?

the AMA at Daytona used a plug that was pushed into the carb intake track, pretty simple stuff.

I think he means wording of the rules rather than physical measurement.

In terms of plug, how does one deal with odd shaped inlets?

[Sketchy_Racer]

Or remove said carb size rule all together and then said newbie doesn't have to get his knickers in a twist over rules and comes racing....

[Bert]

Or remove said carb size rule all together and then said newbie doesn't have to get his knickers in a twist over rules and comes racing....

That will get a few excited...