05 yz125 Woods Conversion

[GNCC280]

Hello,
I am new to the site and I just purchased an 05 YZ125 and so far I love it. I am comming off a 2001 200EXC KTM and I loved the engine of that bike. Does anybody have any input on making the 125 run a little more like the 200(i.e. low end roll on power, less on/off power) I know it won't ever be just like the 200. I race GNCC's and AWRCS. My plan so far is a VForce 3, 9oz. Steahly Flywheel Weight, Pro Circut Platinum Pipe and possible a Pro Circuit Spark Arrestor. I'm installing Race Tech Gold Valves front and rear & reshiming the stacks. Other additions are Cycra Pro Bends, ZipTy Tank, Tag Privateer Kit, Scott Stabilizer and mounts. Any further help would be of great value.
Thanks,
Dan

 

[Detonator]

I think you're on the ball with those mods.

Of course, lower gearing can help your low end. Short of porting your bike or getting a big-bore kit, it sounds like you've got a handle on it. You'll love the flywheel weight.Get some Michelin M12's on there for woods. An autoclutch is a cool add-on, but not necessary.

 

[GNCC280]

I normally run Pirelli's 32 rear and a Scorpion front. I was also thinking about the 12 tooth front sproket but I didn't think the Auto Clutch would work on the smaller 125's. My buddies race 450's and 250's and 200's with them and they all LOVE them. I will have to check into them. What do you guys think about the 9oz. as opposed to the 7 or 11 oz. weights?

 

[2-Strokes 4-ever]

I was a long time 125 woods rider. Just loved the light weight. Ride a 250 now, just because I got tired of doing all those top-ends. On Suzuki's and Kawasaki's you can add low-end by shimming out the expansion chamber... meaning, simply adding more head-pipe length. (2-3-or 4 additional washers/gaskets). You'de be suprised how much of a low-end improvement you can get this way. I think Yamaha's have a different pipe flange, but you can probably work around it somehow. Carbon Tech's "low-end" reeds work well too. I even advance the ignition just slightly. And shaving off the base of the cylinder will help too, if you want to go that far, but you have to watch-out for the added compression... I never liked any form of additional flywheel on a 125, just too hard to get on the pipe. I've heard that the Yamaha's have decent low-end though. If I were you, I'd start with about an 8 oz. weight and have a machinist shave it down if it proves to bog you down. 125's are so fun, but you pay a price on nasty uphills... get on the gas, get aggresive, stand up, and be prepared to chase the rear-end around. But,... in flat, tight woods or on down hills, you will ROCK on your tiddler! Have fun.