Proposal to delete rule 24.2.1 - Alcohol based fuel or fuel additives are prohibited

[goose8]

Come on more bites please. 205cc 4T. That takes to to a nice and fair possible 40 odd hp. 107 2T open and 205cc 4T open. Nice and simple.

I think they might be changing 4t back to 125cc as well, now seems pretty fair go the 2ts.
:bleh

[speedpro]

Just an observation the 107cc will not allow the use of 52mm pistons, if you have a H100/MB100 without destroking. Let alone something with a 50.6mm stroke..
So it is a bit pointless.

MB/H100 standard stroke = 49.5mm, with a 52mm piston makes a 105.12cc engine.

My good engine stroke is 48mm, piston is 52.15 making a 102.5cc engine.

Using standard MB/H stroke of 49.5mm and a piston of 52.45 makes an engine of 106.95.

Actually with a piston of 52.45mm you would run the risk of going oversize as it is the bore dimension which is used to calculate engine capacity. If the bore was 52.47mm the engine capacity would be 107.03cc

As KT pistons are available in .05mm oversizes, even only being able to go to 52.45mm is still 10 oversizes including the original 52.00mm piston.

[husaberg]

MB/H100 standard stroke = 49.4mm, with a 52mm piston makes a 105.12cc engine.

My good engine stroke is 48mm, piston is 52.15 making a 102.5cc engine.

Using standard MB/H stroke of 49.5mm and a piston of 52.45 makes an engine of 106.95.

Actually with a piston of 52.45mm you would run the risk of going oversize as it is the bore dimension which is used to calculate engine capacity. If the bore was 52.47mm the engine capacity would be 107.03cc

As KT pistons are available in .05mm oversizes, even only being able to go to 52.45mm is still 10 oversizes including the original 52.00mm piston.

you are of course right re the 105 and a bit (fat finger the cellphone calc i guess) i would have still liked to see maybe 111 or so for a bit of breathing space for the kawa/yams etc with the 50.6 stoke but the remit looks like it is actually going to save money.........the Cr105 pistons are bloody expensive compared to the strike.............

[avgas]

So you can't have alcohol fuel, but you can have racing wheels, racing tyres, racing forks, racing suspension, lightweights products, changed sprocket ratios, changed gearboxes, racing plugs, racing valves, racing carb internals, efi, after-market computers, modified race frames, fuel pumps, non-original bores, aftermarket exhaust and CDI.

But don't get caught with a racing engine (externals) or alcohol fuel

I dear someone to race a bog standard DR125......oh wait you can't

[F5 Dave]

Ahh, you again. Fuck off wanker.

You don't race here so fuck off back under your own bridge.

[F5 Dave]

Actually the more I think about the learner 125 market overseas they would have made a great basis for a bucket class if you could keep them std. Far more likable than the MX80 route. I'm not seriously proposing it but there is a supply of cheap motors. $500 or $600 would probably land you a passable engine, fire $300 of rodkit & piston at it & you'd have a reliable race engine for under a grand.

[kel]

Actually the more I think about the learner 125 market overseas they would have made a great basis for a bucket class if you could keep them std. Far more likable than the MX80 route. I'm not seriously proposing it but there is a supply of cheap motors. $500 or $600 would probably land you a passable engine, fire $300 of rodkit & piston at it & you'd have a reliable race engine for under a grand.

Cheap modern motors would be nice but we couldn't police the standard motor approach. Besides we already have the off the shelf option of the AM6 motors with their millions of after market kit and big bore parts.

[TZ350]

I would have still liked to see maybe 111 or so

Me to, then 11% more for the 125's ie 139cc ... I would like that very much yess sir .....

But if the 100's really want cheap pistons and 111cc then easy, stay air cooled and use a 24mm carb.

[F5 Dave]

Funny you should mention that as there is also this rule I was about to point out;

Additionally amend:
F4 2 stroke engines over 104cc (7?) are restricted to carburation equivalent to a single 24mm carburettor

[F5 Dave]

Me to, then 11% more for the 125's ie 139cc ... I would like that very much yess sir .....

But if the 100's really want cheep pistons and 111cc then easy, stay air cooled and use a 24mm carb.

check your math, where did you get 11%? 105 to 107 is no where near & 124s are allowed 130 currently.

The 4 bangers got an increase from 150 to 158 a while back. that's 5% more, so 3% more for the 100s seems prudent. Heck we'll be at 750cc by next century

[mr bucketracer]

all I want is just 1cc more . I don't ask for much

[F5 Dave]

after today I'm thinking more along the lines of 750ml

[kel]

check your math, where did you get 11%? 105 to 107 is no where near & 124s are allowed 130 currently.

The 4 bangers got an increase from 150 to 158 a while back. that's 5% more, so 3% more for the 100s seems prudent. Heck we'll be at 750cc by next century

I've done the maths. Both the 100's and four strokes already benefit from a greater % oversize allowance. Why should the 100's benefit further? If the rule change is accepted the 125's will be short changed a full 3%, or more importantly 2 piston sizes. No problem here with the proposed capacity increase, we all want to draw out the service life of cylinders for as long as possible, but any change should be applied to all.

[TZ350]

check your math, where did you get 11%? 105 to 107 is no where near

Check the original post

I quoted, Husaburg suggesting he would be happy with 111 and that is 100 + 11% or was last century when I went to school....

[F5 Dave]

The original post was about gas wasn't it? Oh Husi's post, erm ok then.

Fine. [ask your wide for a translation]