The cheater MX85 argument. I might be changing my mind.

[speights_bud]

Hi GRUMPH. When my sons started racing,the bikes were cb100, cb125, cb125t,gp100,kc,ke100,yb100.This was 18yrs ago .Now we have ,cbr150 ,fxr150,
All liquied cooled ,4valve motors.Is it not time to allow a new two stroke motor.A kx,yz,cr,rm,85 water cooled. If their is concern about these motors being fitted with aftermarket hot up parts ,Be like speedway and pre season dyno them.
WHAT YOU THINK ROBIN

Here's an idea, y'all pay me lots of $$ to supply you crate motors (like moto2) and I'll distribute them randomly and you give them back after each meeting ;-)

[Skunk]

Hi GRUMPH. When my sons started racing,the bikes were cb100, cb125, cb125t,gp100,kc,ke100,yb100.This was 18yrs ago .Now we have ,cbr150 ,fxr150,
All liquied cooled ,4valve motors.Is it not time to allow a new two stroke motor.A kx,yz,cr,rm,85 water cooled.

That's my point. Easy bolt in mid range power without mods by using an FXR, CBR but no two stroke equivalent. MX85 seems the ideal.

Let's test it. (Both the idea and the bikes).


If it ain't smokin', it's broken.

[speedpro]

As an aside, F1 and F2 at the time F3 was started were also open slather classes - with open fuel too.....Ah, Nitro, I miss you.....

My old F1 bike with it's 1973 Z1 engine which made 83hp(cough) when it left the factory, made 175hp with bent valves when run on the dyno. Made a bit more when everything was good. So similar % gains as a lot of buckets. Modern engines are a lot better of course and harder to "improve" to the same degree. Of course they also make more or less the same power without the turbo or methanol.

[CM2005]

My old F1 bike with it's 1973 Z1 engine which made 83hp(cough) when it left the factory, made 175hp with bent valves when run on the dyno. Made a bit more when everything was good. So similar % gains as a lot of buckets. Modern engines are a lot better of course and harder to "improve" to the same degree. Of course they also make more or less the same power without the turbo or methanol.

175 horse!!!!! turbo and or methanol? That is huuuuuge power for one of those. was it 1100cc +?

[speedpro]

Rajay turbo, carb, and intake manifold from a Z1Rtc, 75%methanol, 1075cc. Had run a larger motor with thinner sleeves but had reliability problems. Went smaller and left meat in the sleeves and block. When running it's best it could lift the front at 8,000rpm in top with 15:27 gearing and pulled 9000rpm at Puke in top. 312k according to a cop with his radar.

[quallman1234]

Only glen and i have ridden it, and ill tell you its no easy thing to ride. In fact quite difficult. More difficult than a RS125 to ride.
Honestly as a standard engine they are much more difficult than most people are thinking to ride properly and actually get some speed out of them.
In comparison my FXR was a breeze to ride.
Just pointing out that its way less powerful than you guys think, you use almost all 6 gears at kaitoke.

[jasonu]

Perhaps if more bucket racers looked outside the class, they might drop the above misconception. Then things may get simpler for everyone regarding the outdated rules governing them.
The rules are already very simple

Bet few bucket racers have the slightest idea what is involved in making a competitive superbike motor.

I doubt many of them give a shit otherwise they would already be doing it.

[F5 Dave]

Well Henks (?) Point about std being rare and hard to prove is valid. Std ign and std pipe. . . Or how about alternative pipe you can build your own but with a max diameter of say 80 mm. Easy to measure, but hard to make super power.

[Grumph]

Well Henks (?) Point about std being rare and hard to prove is valid. Std ign and std pipe. . . Or how about alternative pipe you can build your own but with a max diameter of say 80 mm. Easy to measure, but hard to make super power.

I've already said earlier i have no stance on the question but....

Given the shitfight over 250 prod and several other class rule sets i could name, whatever you come up with HAS TO BE ENFORCEABLE !!

To this end, I'd recommend making any restrictions external to the motor. Look at the aircooled/24mm carb 125 rule. simple and enforceable. as soon as you go down the track of "standard barrels" or in one very bad case "engines must be as they came from the original bike" you are simply asking for trouble.

dave may be onto something with the pipe dia idea - it needs someone with engmod to run the figures. A list of ignition boxes approved for each motor, maybe would work too. Anyone still reprogramming them ? Std carb for that motor with untouched bore too...Airbox intake restrictor ?

[avgas]

For what it is worth, in my opinion this thread has run its course and is starting to go in circles.

That's positive. I have just caught up in it.....and I think its going no where at all.

The people whom have said no - have not entertained any suggestions that there are ways for it to work. As far as they are concerned - MX85's are race engines and the rules state "No race engines".
They don't want this rule to change - and can't see anyway where an MX85 is not a race engine.

I believe the term is Stalemate.

Which raises a question - if an MX85 engine came as standard in a scooter. Would it then be allowed to be used in buckets?

[Drew]

Which raises a question - if an MX85 engine came as standard in a scooter. Would it then be allowed to be used in buckets?

Yes. It would then come from a non competition bike.

Here's a good way around it that stirred some shit a while back.

http://raresportbikesforsale.com/tag/nsr80/

To my mind, this makes the CR80 legal.

[Henk]

Yes. It would then come from a non competition bike.

Here's a good way around it that stirred some shit a while back.

http://raresportbikesforsale.com/tag/nsr80/

To my mind, this makes the CR80 legal.

Drew

Steve Bennett has one of these, and the engine bears no resemblance to a CR engine.

I would like some clarification as to what is being proposed now as there seem to be two schools of thought.

Are we looking at stock MX85 engines so people who hate four strokes can bolt a readily available engine into a bike and go racing knowing that they will not be able to tune to the stage they would need to run at the sharp end, or

MX85 engines with the rest open slather to give us a new platform for two stroke development in the class.

There seem to be two trains of thought here and I'm losing track of what is being debated.

[kel]

As I have previously stated there is no point to letting in 85MX if they are going to be limited in any way other than capacity.
Buckets is about developing engines to race. A ported 85 2 stroke against a worked 150 4 stroke is a good match.
The other engine classes can remain unchanged. the best 100cc home built non comp 2 strokes will still produce 30hp, the best air cooled non comp 125 2 strokes will still come close (23hp isn't close) but blow up every second meeting, the best 4 strokes will still dominate the kart tracks with their superior torque curves. I'd like to see non comp 200cc single cylinder 2 valve air cooled 4 strokes added as well.
I will put this forward as a rule change next year. Support buckets or support your own agenda, I don't care.

[Rick 52]

125cc air cooled motors are dangerous ?? Rubbish! TF 125 with a kart carb makes reliable 23hp built and maintained as a race engine, not hard but if you know how, 85mx engine standard bolt in is a easy option, not hard if you know how, both engines are available and make good power .
TF engine needs more work on the bench before use and the MX motor would need a rebuild before use, both engines would cost the same to prep before using but more time on the TF with porting, Henk pointed out 85mx engines are not cheap to buy.
Horses for courses ! I would use a CR85 as a have one under the bench but I'm not sure how much of a advantage I would get,

1/ would this rule change get more bikes on track ? Not in my opinion .
2/ could the rule change open a can of worms ? Very probable
3/ would it be a cheaper option ? No

Haha I voted yes

[husaberg]

I've already said earlier i have no stance on the question but....

Given the shitfight over 250 prod and several other class rule sets i could name, whatever you come up with HAS TO BE ENFORCEABLE !!

To this end, I'd recommend making any restrictions external to the motor. Look at the aircooled/24mm carb 125 rule. simple and enforceable. as soon as you go down the track of "standard barrels" or in one very bad case "engines must be as they came from the original bike" you are simply asking for trouble.

dave may be onto something with the pipe dia idea - it needs someone with engmod to run the figures. A list of ignition boxes approved for each motor, maybe would work too. Anyone still reprogramming them ? Std carb for that motor with untouched bore too...Airbox intake restrictor ?

I agree with Daves idea any restiction needs to be easily checked the ignition is iMO a no go, To easy to pop open and change a resistor to remap........