Husky CR125 dyno graphs and mods?

[husky cr125]

I have recently bought a Jaydee Motorcycles developement Husqvarna CR125 '00 model. The bike uses JD's patent bottom end modification, a Bill's pipe and makes a genuine 36hp. Stock carb, intake, ignition, cylinder/head, muffler. My question is does anyone have any experiance with a Vforce on this bike? Or port timings? Any dyno graphs? I aim to make 40hp. Any assistance will be appreciated.

 

[Taliesin]

Do a search titled "Dyno Requests?" the user Marcusgunby has posted a couple on the Husky 125.His best was for 39.1 Hp for the works Husky 125 of Steven Sword raced in 2001 & early part of world GP's in 02.
As Marcus commmented push the motor passed 36Hp compromised reliability.However Husky carried on with the developement work on Alex Puzars bike in 03 season.He never seemed to have any reliabilty problems & the bike was well quick.As good as the best KTM & Kwaks.
40Hp from a 125 is obivously on the edge.
Have you tried a VHM head? I wonder if they are worth a look or are they just another aftermarket fad?

 

[marcusgunby]

I got 37hp from my RM125 but it was very hard to ride, i detuned it to 36hp and its actually faster on the track,any more than 37hp and it would seriously compromise reliability, if you can imagine a dyno curve is a piece of string, you pull the peak upto 40hp and the sides go inwards and make the power peaky and harder to ride-i would reccomend leaving it 'as is'.

 

[DEANSFASTWAY]

Had a big bore Husky once 58mm With a Yamaha crank and rod Used a take off Mikuni CR250 carb with an airhorn divider to help build some bottom sort of like the power now device. If you put more power into that tiny clutch youll be facing issues as well id imagine .the thing rocked but was never on a dyno

 

[husky cr125]

Not wanting to make the bike super peaky I will take your advice Marcus. However, as 36hp came so easy I am now wanting to try to boost bottom and midrange. I haven't tried the VHM head, I just figured the standard head could be modified to suit. Where should I go from here? Ideas and suggestions will help. Also whatever happened to the boyesen rad valve? Does anyone still use those?

 

[marcusgunby]

Going for more bottom and mid is a good plan IMO-it will be a faster engine if you can keep the nice top end you have now,a std head can be modified to be the same as a vhm, basically you want to close up the squish gap to 1mm(std jap bikes are around 1.3mm)however this will then mean you need to take some volume from the dome to compensate.The rest of the head mods depend on what fuels you run etc, you really need to have it done using the computer program that calculates the maximum squish velocity.I know eric gorr uses this program as do some others.

I would look to try a boyesen 3 rad valve-they are better than the previous ones.

The best way to make sure you have good power is to set the bike up on a dyno, you can try timing changes, pipe spacers even a different heat range plug can make a difference eg in the winter.Ive seen bigger gains on the dyno from carefull setup than any bolt on mod.