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

**Yow Ling** · 9th February 2016, 16:33

Originally Posted by TZ350

Thanks Husa. You know, that link does not work for me, strange!!!!

Ok so now we have the up to date 2015 text with the rule change possibilities and an S after the word "Kart motor".

Option 1, a refined definition of 24mm carb equivalent that takes into account EFI and throttle plate carbs like the Tillotson pumper carb.

Chapter 24 – Road Racing – Miniature
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 and F4 2 stroke engines of less than 70cc 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 (24mm equivalent) 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

Option 2 same as 1 but without the F5 4T 20mm carb restriction

Chapter 24 – Road Racing – Miniature
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 and F4 2 stroke engines of less than 70cc 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 (24mm equivalent) 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.

Option 3, no carb restrictions at all.

Chapter 24 – Road Racing – Miniature
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 and F4 2 stroke engines of less than 70cc capacity, which may be turbo or
supercharged.

Now if we could have no restrictions on fuel type or additives for 4T's of less than 100cc and 2T's of less than 70cc then we could see some very interesting machines indeed.

I think this is worded just for your own needs, maybe it would be better and fit the purpose for which it was intended if it read
F4 2 stroke engines over 104cc ; At some point in the inlet tract(s) between throttle slide or butterfly and crankcase or barrel, the inlet tract(s) shall not exceed an area of 452mm2 (24mm equivalent) 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.

**Skid Mark** · 9th February 2016, 16:47

Simple question can I run a 50cc 2t in f4

**seymour14** · 9th February 2016, 16:55

Originally Posted by Skid Mark

Simple question can I run a 50cc 2t in f4

You can, but don't get run over.

**mr bucketracer** · 9th February 2016, 16:57

Originally Posted by seymour14

You can, but don't get run over.

club meets but dont think a gp

**mr bucketracer** · 9th February 2016, 17:07

only one new rule i would like ,only realy for us heavy weights if people want to play fair , 2 things 190kg+ bike rider combo more cc's or weigh your bike up , i rode regans new bike the other day and was shock horered what 10kg less in a bike on how it feels like there is no bike under you!! you gay light weight riders dont have any idea on how good you have it ! guess you will all be scared pumba , nick, rich, and me and other fast heavey weights would smash you all

**Skid Mark** · 9th February 2016, 17:08

So have I got it right that the rule states 55cc to100cc water cooled yes so 50cc is not enough to meet f4 class yes or no

**jasonu** · 9th February 2016, 17:20

Originally Posted by mr bucketracer

only one new rule i would like ,only realy for us heavy weights if people want to play fair , 2 things 190kg+ bike rider combo more cc's or weigh your bike up , i rode regans new bike the other day and was shock horered what 10kg less in a bike on how it feels like there is no bike under you!! you gay light weight riders dont have any idea on how good you have it ! guess you will all be scared pumba , nick, rich, and me and other fast heavey weights would smash you all

There should be a ban on fat cunts.

**rambaldi** · 9th February 2016, 17:22

Originally Posted by jasonu

There should be a ban on fat cunts.

Fuck that, the skinny cunts need to ride around with ballast. I ain't going to the gym.

**TALLIS** · 9th February 2016, 18:43

Originally Posted by Skid Mark

So have I got it right that the rule states 55cc to100cc water cooled yes so 50cc is not enough to meet f4 class yes or no

Your bike will be classed as f5 regardless. The race groups are usually "a" "b" and possibly "c" depending on your lap times. Then your bike is classed f4 or f5 depending on what it is.... hope you can understand

**Grumph** · 9th February 2016, 19:02

Originally Posted by Yow Ling

I think this is worded just for your own needs, maybe it would be better and fit the purpose for which it was intended if it read
F4 2 stroke engines over 104cc ; At some point in the inlet tract(s) between throttle slide or butterfly and crankcase or barrel, the inlet tract(s) shall not exceed an area of 452mm2 (24mm equivalent) 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.

Well I tried to word things to leave it as open for experiment as possible. As you'd know, I have no axe to grind - or skin in this particular game.
If you're inferring that what may result is an airbox/plenum chamber with a 24mm entry, why not ? It's been proved I think that the carb throat size ain't a limiting factor, at least at 24mm.
Have a look at most kart classes, they have to run a specific airbox - with a couple of small entry holes. Allegedly as an intake silencer...
The way you've worded it means the carbs which have the restriction either before or at the slide/butterfly won't be legal.

**Skid Mark** · 9th February 2016, 19:11

So what your saying is a 50cc non comp 2 stroke is to small for f4 So the derbis 49.9 is to small for f4 also and the rs aprilia is also well under class capacity so how is that allowed ??

**jasonu** · 9th February 2016, 19:20

Originally Posted by Skid Mark

So what your saying is a 50cc non comp 2 stroke is to small for f4 So the derbis 49.9 is to small for f4 also and the rs aprilia is also well under class capacity so how is that allowed ??

No. What he is saying is read the fucking rules. it is all there.

**TZ350** · 9th February 2016, 19:22

Originally Posted by Yow Ling

I think this is worded just for your own needs, maybe it would be better and fit the purpose for which it was intended if it read
F4 2 stroke engines over 104cc ; At some point in the inlet tract(s) between throttle slide or butterfly and crankcase or barrel, the inlet tract(s) shall not exceed an area of 452mm2 (24mm equivalent) 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.

Actually after advice submitted on this thread and by PM, my proposal was worded as best I could to be a very good reflection of the existing rule without changing it but refines the definition of 24mm equivalent to cover a wide range of carburettor types and EFI throttle bodies in an unambiguous way without changing the thrust of the original rule itself. Yours might have a hidden agenda as your proposal restricts things in a way the original rule did not.

At this point I intend submitting my proposal the way it is and if it is accepted by MNZ you will get a chance to put your views forward on its merits to them in April.

**F5 Dave** · 9th February 2016, 19:25

Not trying to be rude mark, but you've pointed it out and you still want someone to tell you different?

F5 is where its at and its legal.

**TZ350** · 9th February 2016, 19:29

Originally Posted by Skid Mark

So what your saying is a 50cc non comp 2 stroke is to small for f4 So the derbis 49.9 is to small for f4 also and the rs aprilia is also well under class capacity so how is that allowed ??

When has an Aprilia 50 been allowed to run in F4, it is news to me. I have seen a few 50's in B grade but F4???