Renner RedBuuuuddd! on the 125.

[Kurtis]

I am really starting to believe a top pro on a updated works 250 would have a shot in the 450 class for motocross.  Super cross would be a bit tougher with the way the tracks are setup without a little added displacement but motocross it seems completely feasible.   The top 250f guys times are close to the 450 times and a 250 2t set up to race could easily pump out 15 more hp and 12 more lbs of tq than a 250f while being 10 lbs lighter.  It could also sacrifice a bit of peak power and have a power curve that could give the thumper a run for its money in tractability while still being up 10 total hp most of the way.  If they did ever give the 250 injection and get it set up right I would not doubt a 56-58hp 250 with an extremely long piston life.  It should bring its efficiency up quite a bit and show some impressive gains.   

[twosmoke595]

That extra hp does indeed help, and the factory 250's are pushing 42-44hp. At that point its shock that the 125 made it at all.

i would not be surprised if they were nearer to 50

[chump6784]

That extra hp does indeed help, and the factory 250's are pushing 42-44hp. At that point its shock that the 125 made it at all.

i would not be surprised if they were nearer to 50

2012 kxf250 makes pretty much 40 hp stock. MXA did an article where they took a crf 250 and put an exhaust, cams and computer on it and got nearly 4 hp more out of it iirc. So there you are looking at 43 to 44. I have seen dyno graphs of a 250f with a flowed head getting 2 hp increase, also race gas gives 1-2 hp increase. With those mods you are looking at around 48 hp.

Not bad figures when you consider all that power gets put to the ground and is easy to control. Now ama, tell me how it is unfair to race cc vs cc. We are not talking Honda XR's anymore.

In topic, well done Ricky, I was glued to my computer screen trying to get some smoker action

[twosmoke595]

That extra hp does indeed help, and the factory 250's are pushing 42-44hp. At that point its shock that the 125 made it at all.

i would not be surprised if they were nearer to 50

2012 kxf250 makes pretty much 40 hp stock. MXA did an article where they took a crf 250 and put an exhaust, cams and computer on it and got nearly 4 hp more out of it iirc. So there you are looking at 43 to 44. I have seen dyno graphs of a 250f with a flowed head getting 2 hp increase, also race gas gives 1-2 hp increase. With those mods you are looking at around 48 hp.

Not bad figures when you consider all that power gets put to the ground and is easy to control. Now ama, tell me how it is unfair to race cc vs cc. We are not talking Honda XR's anymore.

In topic, well done Ricky, I was glued to my computer screen trying to get some smoker action

because with a 250 2 stroke you can make them near 60 hp and up, THAT"S why they dont like it lol

[factoryX]

I don't honestly think its all easy to put to the ground even with a works 250f. They are going to want less resistance to pull more power from the motor. This means that the counter balancer(If there is one), and the fly wheel weight are going to be extremely light(Stock 4t fly wheels are pushing 14-20oz).

[factoryX]

That extra hp does indeed help, and the factory 250's are pushing 42-44hp. At that point its shock that the 125 made it at all.

i would not be surprised if they were nearer to 50

No replacement for displacement. Those 250's are running 76-78mm bores(yz125 54mm, yz250 66.4mm)...

[Stusmoke]

Anyone know what the late cult of factory 125 mxers made? Stewerts or Carmichaels? It'd be interesting to see how they stack up.

[ringadingding]

Anyone know what the late cult of factory 125 mxers made? Stewerts or Carmichaels? It'd be interesting to see how they stack up.

Exactly what i was thinking, but even if the HP is close can you imagine the power curve on a 125 with 40ish hp  would be kinda deadly, even for a pro 

[lauterbacher]

Yes I believe that Stusmoke hits it on the head when he asks if anyone knows any numbers for the factory two stroke, It's like in the mags now they'll try every hop up part on a 4 stroke and dyno them but do you ever see a article on the 125 and what they can get out of them? And actually have them dyno'ed

[VintageBlueSmoke]

Anyone know what the late cult of factory 125 mxers made? Stewerts or Carmichaels? It'd be interesting to see how they stack up.

RC or JS factory bikes are not the ones to look at. Look to Europe, who never had a "production" rule. I bet there were some trick machines in the end...

[monsteryz125]

That extra hp does indeed help, and the factory 250's are pushing 42-44hp. At that point its shock that the 125 made it at all.

i would not be surprised if they were nearer to 50

No replacement for displacement. Those 250's are running 76-78mm bores(yz125 54mm, yz250 66.4mm)...
Displacement is determined by bore and stroke not just bore

[nom de guerre]

I bet JS's 125 was pumping out some serious HP over a narrow spread... he was the end of an era and sure made the 250f bikes look silly.

[snook620]

Anyone know what the late cult of factory 125 mxers made? Stewerts or Carmichaels? It'd be interesting to see how they stack up.

Id say 36-38hp. Baggett jumping the leap this weekend really shows how much power PC is getting out of those 250f's, Im sure the 125's of the time were just as impressive.

[Super Trucker]

In the race I heard Renner was whipping it and fist pumping it over all the jumps  . That,s what it,s all about, having a awesome time riding your 125. He must have blew the minds on the 1st time national spectaters, pure excitement. Thx Ricky.  A  stock KTM used to make 38 hp, a cr is just under 35 stock, a YZ is about the same. More important than hp, is that the factory riders get exactly what powerband they want. A 125 with porting, ignition, pipe and silencer, borred carb can make 40 hp running on leaded race fuel.

[Stusmoke]

In the race I heard Renner was whipping it and fist pumping it over all the jumps  . That,s what it,s all about, having a awesome time riding your 125. He must have blew the minds on the 1st time national spectaters, pure excitement. Thx Ricky.  A  stock KTM used to make 38 hp, a cr is just under 35 stock, a YZ is about the same. More important than hp, is that the factory riders get exactly what powerband they want. A 125 with porting, ignition, pipe and silencer, borred carb can make 40 hp running on leaded race fuel.

Thats what I thought too. At least. God knows what they do to their bikes when they're putting the engine together. Considering the 250 factory bikes could make 62 horsepower (heard it on here somewhere) I'd say 40 HP for a 125 is not a push.

Hey does anyone else notice that when the 250F or 450 shootout time roles around no fewer then one of the bikes have bad or not so good handling? How many 125s/250s did? Honestly in those later shootouts when did they ever say the KX has heavy handling or jerky handling? Yet here kawasaki is with handling issues having plagued their line of 250Fs and 450s since their introduction. Way to go:P