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

[kel]

So also, if one wanted to submit a rule change how does one go about doing so? Does it need to be submitted to a club to represent the change then they forward it onto MNZ?

Not that I'd know anything about this ...

We would like to remind you that all rule changes for 2016 must be submitted to the MNZ Office on the correct form before the 1st of March 2016
To assist you in this process we have links to the correct forms below.
https://www.mnz.co.nz/docs/default-s...e.pdf?sfvrsn=2
https://www.mnz.co.nz/docs/default-s...1.pdf?sfvrsn=2
https://www.mnz.co.nz/docs/default-s...r.pdf?sfvrsn=2

[TZ350]

Have we not all learnt from TZ's and Kels 125 Aircoolers that even if you took away the carb restriction the things wont handle more than 30hp at best before thermal melt down.

So removing the carb restriction just gets rid of a silly hard to define and police rule around carb size measurement.

Without the carb restrictions (F4 & F5) and that "S" the current rule blurb looks like this:-

Chapter 16 – Road Racing – Miniature

16.2 - Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro
and Go Kart motor 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.

The current rule blurb without any carb restrictions is just three sentences .... pretty simple.

[TZ350]

Maybe this could work.

Chapter 16 – Road Racing – Miniature

16.2 - Engines must be derived from non-competition motorcycles or home built in whole or part. Motocross, Road Racing, Enduro and Go Kart motor and transmission parts are not permitted except for the capacities specified.

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.

Three sentences, now just add suitable capacities.

[Sketchy_Racer]

Maybe this could work.

Chapter 16 – Road Racing – Miniature

16.2 - Engines must be derived from non-competition motorcycles or home built in whole or part. Motocross, Road Racing, Enduro and Go Kart motor and transmission parts are not permitted except for the capacities specified.

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.

Three sentences, now just add suitable capacities.

\

Love it!

[jasonu]

Have we not all learnt from TZ's and Kels 125 Aircoolers that even if you took away the carb restriction the things wont handle more than 30hp at best before thermal melt down. So removing the carb restriction just gets rid of a silly hard to define and police rule around carb size measurement.

!!

Are you sure thermal melt down due to the 24mm carb is the problem? TZ has said numerous times the 24mm carb isn't the limiting factor and I am still not sure why he is hell bent on getting rid of that rule). I think it is more of an engineering, design and execution issue that holds back the 125's...
If you remove the carb restriction and the 30hp 125 2t air coolers go better and actually hold together (I am not convinced they will) then they should easily dust all of the 100cc 2t water cooled bikes. How is that fair? The 100cc 2t water cooled folks will then want some sort of leveler... then the diesels will want more...
As for 85mx motors, that is the easy way for lazy cunts to get good HP. Put one of those in a (say) NX4 chassis, breath on it a bit, light touch paper and stand back

[Sketchy_Racer]

Are you sure thermal melt down due to the 24mm carb is the problem? TZ has said numerous times the 24mm carb isn't the limiting factor and I am still not sure why he is hell bent on getting rid of that rule). I think it is more of an engineering, design and execution issue that holds back the 125's...
If you remove the carb restriction and the 30hp 125 2t air coolers go better and actually hold together (I am not convinced they will) then they should easily dust all of the 100cc 2t water cooled bikes. How is that fair? The 100cc 2t water cooled folks will then want some sort of leveler... then the diesels will want more...
As for 85mx motors, that is the easy way for lazy cunts to get good HP. Put one of those in a (say) NX4 chassis, breath on it a bit, light touch paper and stand back

I can't imagine that changing the carb will change anything with the thermal issues. If you're making that level of power and you can't improve the thermal efficiency of the motor with fuels like alcohol then you'll always be up against the wall at 30hp. Let's not forget that it is actually quite a challenge to get them to 30hp in the first place.

As for 85s been the easy way out, then yes they are which is the point, because not everyone wants to build motors. As for putting one in a RS chassis and waxing everyone; that combination already exists, it just has "Derbi Racing" on the side of it and is deemed legal aparently.....

[Cheesy]

Now I don’t have a bucket (well actually I do but its for spare parts), and I have never been to a race. But this little corner of the internet is very interesting and a good place to learn from those that contribute their hard earned knowledge. So with that in mind take this suggestion with a grain of salt.
Chapter 16 – Road Racing – Miniature

16.2 - Engines must be derived from non-competition motorcycles. Motocross, Road Racing, Enduro and Go Kart engines are not permitted. For the definition of this rule an engine is considered crank cases and cylinder(s)

4T-160cc Naturally Aspirated
4T-110cc Forced Induction
2T-130cc Air Cooled Naturally aspirated
2T-110cc Naturally Aspirated
2T-70cc Forced Induction

Reasoning; overbores are gone and replaced with a hard capacity limit (my numbers may not be correct though), makes the rule simpler. Carburation limit removed as it has been shown that it is not a limit, it also had unintended implications with overbored 100cc 2Ts. Open engine components, simply it opens a wider range of parts that are more easily available, rod kits and pistons are much easier to get for a modern MX bike than an old commuter bike and the parts themselves are not going to give a huge performance advantage. As it is now someone could design a piston and get it custom made, said piston may be exactly the same as some 105cc MX bike but cost 10x as much. Similarly, with transmission parts. Calling an engine a set of cases and cylinder is just an arbitrary line in the sand that seems to keep the spirit of the bucket class as it is now (well to me anyway).
I think allowing the competition engines would open a whole can of worms, they could be good worms or bad worms but it would cause some pretty big changes to the class. Maybe there could be a separate mini supermoto class for the 85s and 150s?

[jasonu]

I can't imagine that changing the carb will change anything with the thermal issues. If you're making that level of power and you can't improve the thermal efficiency of the motor with fuels like alcohol then you'll always be up against the wall at 30hp. Let's not forget that it is actually quite a challenge to get them to 30hp in the first place.

As for 85s been the easy way out, then yes they are which is the point, because not everyone wants to build motors. As for putting one in a RS chassis and waxing everyone; that combination already exists, it just has "Derbi Racing" on the side of it and is deemed legal aparently.....

Yes mate I know just how much work goes into building a competitive reliable decent HP motor.

If you want to include 85cc mx'rs then how long do you think it will take until someone wants to run a CRF150R's as well?

[kel]

Are you sure thermal melt down due to the 24mm carb is the problem? I think it is more of an engineering, design "removed, cheeky bastard" that holds back the 125's...

You are absolutely right, there's an inherent design flaw i.e. air cooling.
Have a look at the air cooled racers and motocrossers from the seventies , they never made the sort of power we are pulling out of these things. The Japanese aren't silly, they could have made more power but they new to win first you have to finish.

[husaberg]

Have we not all learnt from TZ's and Kels 125 Aircoolers that even if you took away the carb restriction the things wont handle more than 30hp at best before thermal melt down. So removing the carb restriction just gets rid of a silly hard to define and police rule around carb size measurement.

I!!

If the restriction is so unimportant there thus should be no issue leaving it in place then is there...............
Yhat old silly rule was designed to be a restriction.

No one has explained why all of a sudden all the other bikes CC need to get bigger but not the 100cc 2 strokes.

[jasonu]

If the restriction is so unimportant there thus should be no issue leaving it in place then is there...............
Yhat old silly rule was designed to be a restriction.

No one has explained why all of a sudden all the other bikes CC need to get bigger but not the 100cc 2 strokes.

That is my angle too.

[TZ350]

Are you sure thermal melt down due to the 24mm carb is the problem? TZ has said numerous times the 24mm carb isn't the limiting factor and I am still not sure why he is hell bent on getting rid of that rule.

I think it is nothing to do with the carb, thermal melt down will be due to the air cooling being unable to shed the waste heat generated from 30+hp.



I once did a back to back test between a std 24mm OKO carb red line, and another OKO 24 bored out to 30mm, blue line. Both carbs were identical in style and layout and both with jetting optimized. Not as big a difference as I expected.

The 24mm carb restriction does not stop tuners from making 30hp or more but a 30+hp 125 seems to have gone beyond what air cooling can handle reliably. Even the air cooled factory race bikes of the 60's and 70's only made mid twenties power.

The legitimacy of my carburettor tuning has been questioned because I can make a tuned 24 flow as well as a factory 30. How to do it is no secret.

People have questioned the legitimacy of improving 24mm carbs so they flow better. The same people have never stopped to question the legitimacy of improving 2T cylinders, clearly they are both a legitimate Bucket thing to do.

Personally I would mourn the loss of the 24 rule because I have had so much fun with it. I have found and published so many ways to defeat it (if it was ever a real restriction on power???) that it is now irrelevant.

If the 24 thing makes people feel better and they want to continue with the comfortable illusion of a 24mm restriction, then sure, that is my first choice but the rule probably needs to be better defined to also cover EFI and throttle plate carbs like the Tillotson pumper as well as the usual motorcycle slide carbs.

The next best thing is to get rid of both carb restriction rules and cut two complicated unnecessary sentences out of the F4 F5 rule book wording.

In broad terms, carb restrictions are irrelevant in limiting power, but cooling ability is everything and air cooling does not cut it.

[husaberg]

I think it is nothing to do with the carb, thermal melt down will be due to the air cooling being unable to shed the waste heat generated from 30+hp.



I once did a back to back test between a std 24mm OKO carb red line, and another OKO 24 bored out to 30mm, blue line. Not as big of a difference as I expected.

The 24mm carb restriction does not stop tuners from making 30hp or more but a 30+hp 125 seems to be beyond what air cooling can handle reliably. Even the air cooled factory race bikes of the 60's and 70's made mid twenties power.

The legitimacy of my carburettor tuning has been questioned because I can make a tuned 24 flow as well as a factory 30. How to do it is no secret.

People have questioned the legitimacy of improving 24mm carbs so they flow better. The same people have never stopped to question the legitimacy of improving cylinders, clearly they are both a legitimate Bucket thing to do.

Personally I would mourn the loss of the 24 rule because I have had so much fun with it. I have found and published so many ways to defeat it (if it ever was a real restriction on power) that it is now irrelevant.

If the 24 thing makes people feel better and they want to continue the comfortable illusion of a 24mm restriction, then sure, that is my first choice but the rule probably needs to be better defined to also cover EFI and throttle plate carbs as well as the usual motorcycle slide carbs. The next best thing is to get rid of both carb restriction rules and cut two complicated unnecessary sentences out of the F4 F5 rule book wording.

In broad terms, carb restrictions are irrelevant in limiting power, but cooling ability is everything.

But that's the kicker if it is truly irrelevant why the need to get rid of it,
I am pretty sure if a bit of development time was spent optimising for a larger carb the HP would go up. and the spread of power would become wider with a larger carb.
Also why do the f4 four strokes need to get bigger? there is no valid explanation offered thus far as for why this needs to happen?

[kel]

Also why do the f4 four strokes need to get bigger? there is no valid explanation offered thus far as for why this needs to happen?

did someone say 110cc 2 strokes

[mr bucketracer]

Originally Posted by husaberg)
Also why do the f4 four strokes need to get bigger? there is no valid explanation offered thus far as for why this needs to happen?...................
its the only rule that should change ,only wait for the blow ups