Well said. Is there any similarity in the actual power curve readings from dyno to dyno. Peak numbers seem to vary due to many different conditions, seems the curve would be pretty consistent to your setup. Dyno experts please chime in.

 

Ya, I noticed that on the KK stock run, which makes me think that motor may have been a bit worn or at least not running at peak tune & performance for the stocker. If "old" was a good representation of an unmodified stock KLX and the increase from "old" to "330" are the comparative values, than does the 330 put out more power and torque than the 351? I think not likely.

I'd like to see one of BB's dyno runs with the modified exhaust. I believe it was posted on his old web site, but I didn't keep a copy.



(yes, I understand these may be comparing apples to oranges.)



If HMF's dyno runs are a good representation, than an improved exhaust and re-jet are significant.

 

At what point in displacement does the stock head/cams restrict performance. The way the 351 drops off after 6500 rpm makes me wonder. Nice work combining all the dyno graph info.

 

Agreed and good point. But remember Bill's 351 curve was still using the stock exhaust and carb. I think most around here agree the stock exhaust is very restrictive. It's not clear if the carb was rejetted. I assume it was rejetted although he just calls it stock carb.

And to the good points TNC makes above as to trailability, I don't generally wring the motor out so the 351 works well for my use. I'm trail riding, not racing. Don't spend much time above 7,500 rpm.

 

I do not like the 351cc. Range has little use and is more fragile ..
Much better kk331

 

I've found that these same variables apply to my butt dyno.

Ron

 

guys,
what mpg do you get on 351 with mikuni carb?

thanks

 

I'm currently waiting shipment on my 351 kit with Mikuni carb from Bill (awesome, finally getting it done). I consider myself 95% dirt, that's all I'm interested in riding. But in northern MA I need to jump up to NH now which is 30-50 miles of highway - don't like it, but I do it to get the good trails - lots of tight twisty, heavy mud, rocky hill climbs - not fire road cruising.
To handle the highway miles, Bill says a 15t will slow the rpms for extended miles at highway speed (70+ mph).
So my question is - will the 351 + 15t front sprocket be trail worthy? I'm stock rear sprocket.
I'm totally stoked w/ trail grunt now (250+stage 2 DJ+K&N air filter+KDX200 snorkel+TB slip on), but am both ready for more trail power and NEED better highway guts to deal with MA traffic - pigeoned in traffic 65-69mph between a grey beret and a semi is something I'm unwilling to continue dealing with.... Though convincing wifey of 2nd bike (650...) is a few more years off. Inevitable yes, but impossible now.
Can anyone share experience with 15t on true trail riding? Is 1 gear too high? Does it still pull hard in 1-2 gears? Other gear suggestions? Smaller rear sprocket vs bigger front?
Thanks!

 

Nice first post. Looks like you're doing it right. Welcome to the forum. I think you're in virgin territory with a 15 on the trails compared to other reports here. Let us know how it goes. I also think once you get her all broke in, you'll do okay with a 14T front on hwy. Another option is to carry tools and a smaller front sprocket for when you hit the trails. I regularly change my front depending on where I ride...13, 14 & 15.

if you're a gearing geek, check gearingcommander.com

 

Thanks for the gear info you sent me IDRIDR. My next task is learning how to quickly/easily change the CS. Once I pick up a 15t, I'll start experimenting with the 13/14/15, and report back.