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

[Sketchy_Racer]

I suppose I could print a million or so "Not for Race Use" labels to legitimise any questionable parts
$50 for a roll of 250

Attachment 297216

I could also add to CNC engraving any cylinders and competition engines that people want in

[mr bucketracer]

http://www.trademe.co.nz/motors/moto...-538591527.htm
tf motors still built today . newer than fxr motors so guess parts not a promblem

[ken seeber]

OK fellers, I have been reading this interesting thread & lightheated banter from the start and I can see the dilemma. Living in West Oz, I have never even seen a bucket, so am a complete outsider.

How about something else to consider?

Firstly though, what do you want, particularly to allow 2 strokes to continue with the 4 strokes, which seem to have some advantages in terms of cost and easier rideability? To me it might be something like:

1. Maintain the fun factor
2. Allow guys to continue and fiddle/modify motors should they choose, certainly in some specific classes or sub divisions
3. Keep the costs down
4. Provide a platform that offers ready parts and can continue for a useful time into the future.

Here's a thought.

Allow kart engines into the mix. basically this would be mounted on a, say 10 mm aluminium, base plate (to suit the regular kart engine mounting points) that would pass under the engine and pass back towards the swing arm pivot. How this would be connected to the frame would be on a case by case situation. Also on the baseplate would be a simple jack shaft that would be spinning at around 1/3rd engine speed reduction, from there to the back wheel. It would be a fixed ratio installation ie, no gearbox ratio issues . Simple and cheap.

So, you get a huge range of engines to play with, simple centrifugal clutch, ability to start the engine via an elec starter at the accessible crank ends and the exhaust (short) faces rearwards with carb in front (not sure how the exhaust would pass by a twin rear shock rear end though).

Engines could be water cooled 125s (Max, X30, Fireball & SQ). These could be left standard and there are heaps of rule systems in place to use (if the performance it too great, then it would be a simple matter to introduce exhaust restrictor plates as is done in Oz karting). There could also be KT100S, which now are cheap as chups. Maybe these, as nominally aircooled, piston port 100cc engines, have a ready supply of pistons, rings, rods bearings etc. Given the technical disadvantage compared to the 125s, suggest that these could be the fiddlers class, stuff all rules and maybe allow up to 110 cc or so, using up to 55 mm pistons.

That's my input and feel free to tell me to piss off, as I am just a total outsider.

Long live the 2 stroke !!

Thanks

Ken

[F5 Dave]

http://www.trademe.co.nz/motors/moto...-538591527.htm
tf motors still built today . newer than fxr motors so guess parts not a promblem

Oh well problem solved. 4 grand, Bolt up & 10 or so HP is there for the use with stella reliability. Hold me back.

[F5 Dave]

Well that may be just what happens here in welly. Because we don't run MNZ here it comes down to the organisers of the event who can run what. I if a half dozen 85s turned up (which I doubt) they would probably just get crossed classed. At the moment I just start way off the back of any points races to make sure I don't get in the middle of them until at least half way through the race. If some of the fast guys were racing I wouldn't make the ground up on them anyway.

They really aren't going to risk the formula for buckets, well the risk is certainly so minimal. I know Kel is going to submit for a rule change as will I. I really want them in, it's my own agenda i'm pushing of course but I do genuinely believe they will only add to the interest in buckets and in no way be detrimental to the class, again just my own view on the matter.

Some of this discussion is far too well mannered. I'm going to insult your mothers year 4 school teacher just to spice things up a little

[F5 Dave]

I could also add to CNC engraving any cylinders and competition engines that people want in

And yet you missed a trick on your own bike.

[mr bucketracer]

Oh well problem solved. 4 grand, Bolt up & 10 or so HP is there for the use with stella reliability. Hold me back.

skunk said you can get these engine for $40 . last one a did up was around 300 dollar 2 years ago

[husaberg]

Gearbox ratios


87cr CR(ac) MB5 MB100
1st 2.33 2.50 3.17 3.083
2nd 1.72 1.77 2.06 1.882
3rd 1.40 1.40 1.50 1.400
4th 1.17 1.13 1.17 1.130
5th 1.00 .96 1.00 0.960
6th .88 .81 0.88

[Sketchy_Racer]

OK fellers, I have been reading this interesting thread & lightheated banter from the start and I can see the dilemma. Living in West Oz, I have never even seen a bucket, so am a complete outsider.

How about something else to consider?

Firstly though, what do you want, particularly to allow 2 strokes to continue with the 4 strokes, which seem to have some advantages in terms of cost and easier rideability? To me it might be something like:

1. Maintain the fun factor
2. Allow guys to continue and fiddle/modify motors should they choose, certainly in some specific classes or sub divisions
3. Keep the costs down
4. Provide a platform that offers ready parts and can continue for a useful time into the future.

Here's a thought.

Allow kart engines into the mix. basically this would be mounted on a, say 10 mm aluminium, base plate (to suit the regular kart engine mounting points) that would pass under the engine and pass back towards the swing arm pivot. How this would be connected to the frame would be on a case by case situation. Also on the baseplate would be a simple jack shaft that would be spinning at around 1/3rd engine speed reduction, from there to the back wheel. It would be a fixed ratio installation ie, no gearbox ratio issues . Simple and cheap.

So, you get a huge range of engines to play with, simple centrifugal clutch, ability to start the engine via an elec starter at the accessible crank ends and the exhaust (short) faces rearwards with carb in front (not sure how the exhaust would pass by a twin rear shock rear end though).

Engines could be water cooled 125s (Max, X30, Fireball & SQ). These could be left standard and there are heaps of rule systems in place to use (if the performance it too great, then it would be a simple matter to introduce exhaust restrictor plates as is done in Oz karting). There could also be KT100S, which now are cheap as chups. Maybe these, as nominally aircooled, piston port 100cc engines, have a ready supply of pistons, rings, rods bearings etc. Given the technical disadvantage compared to the 125s, suggest that these could be the fiddlers class, stuff all rules and maybe allow up to 110 cc or so, using up to 55 mm pistons.

That's my input and feel free to tell me to piss off, as I am just a total outsider.

Long live the 2 stroke !!

Thanks

Ken

I've got to say you summed it up in your 4 bullet points, But I am not going to lie, a single speed auto 2T would have to be the most boring bike in the world to race. The fun and excitment of 2Ts are the feeling of thrashing the tits off them to get good drive and banging them through the 'box.

A twist and go would be a no go

[Grumph]

Well all the talk of a remit is too late for this year anyway.

may i suggest sending the one running 85 around the country for the next 6 -8 months to let people have a look at it and decide for themselves. Send it down for BoB too - if you can't come we'll find a good pedaller...

All very well to talk forever but if you want change you've got to show some benefit - and prove it won't obsolete existing bikes.

[F5 Dave]

Gearbox ratios


87cr CR(ac) MB5 MB100
1st 2.33 2.50 3.17 3.083
2nd 1.72 1.77 2.06 1.882
3rd 1.40 1.40 1.50 1.400
4th 1.17 1.13 1.17 1.130
5th 1.00 .96 1.00 0.960
6th .88 .81 0.88

Do I read that as 3rd is close & 4-6th where it matters are the same? Cool, as I suspected.

[Sketchy_Racer]

Well all the talk of a remit is too late for this year anyway.

may i suggest sending the one running 85 around the country for the next 6 -8 months to let people have a look at it and decide for themselves. Send it down for BoB too - if you can't come we'll find a good pedaller...

All very well to talk forever but if you want change you've got to show some benefit - and prove it won't obsolete existing bikes.

Well i'm certainly hoping to get around on it but I would be more than happy to send it down to BoB for someone to have a skid on. I want to try come down myself but I'll have to wait and see. (New job means I might be overseas for periods of time)

I'm planning on buying an ignitech soon for the supercharger project, I'm also curious to see how the 85 would react to some ignition and possibly better carb and intake setup. Unfortunatly I am the wrong person at trying to tune this thing to the limit (nor is it my interest with the 85) but it would be nice to see how well these things react to some good engine work.

[Sketchy_Racer]

And yet you missed a trick on your own bike.

Did you not see the crafty hand writing on the cylinder??

[husaberg]

Do I read that as 3rd is close & 4-6th where it matters are the same? Cool, as I suspected.

i tried a table but got lost sorry
In my experience on the medium tracks with the correct gearing the MB5 box was effectively a five speeder.first was either unusable or 6 was too high
On kart tracks getting to the first corner ahead is an advantage. So the closer bottom 3 ratios is an advantage
On tight kart tracks it was no real issue with the gearing per-say,other tha the starts. I never ran it on Ruapuna but strongly suspect the cr box would have been a rather large advantage their.

[Skunk]

skunk said you can get these engine for $40 . last one a did up was around 300 dollar 2 years ago

Yep, I got several basket case TF125s for around that price.
Good points:
About $200 to rebuild if the barrel only needed a hone, including piston, rings and little end.
Bad points:
No porting and no power (9hp factory claim) for that price. Crank costs bigger money.

They are cheap and available but they are not bolt in competitive.


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