finally got it all dynoed! THE RESULTS ARE IN!

Bill Blue 351, tm36-68, slip on exhaust, stock cams, stock header, no air box lid

~28 horsepower
~23 ft lbs of torque! Yummm.

I am extremely lean from idle to 4 or 5k rpm, and a tad rich up top, we adjusted the pumper to come on sooner made a big difference, but not enough, either need a larger pilot, or as he suggested, a smaller air jet.

http://vid293.photobucket.com/albums...n/IMG_2159.mp4




I didn't get an AFR chart, I'll call him and have him email it to me. The best way I can describe it is it starts really up high, around 18:1, then dives down till around 5k where it levels out around 13.5:1-14.2:1


101.9 degrees, 22% humidity, SAE 1.11

 

28HP is kind of less than I thought...but 23 torque is sweeeet.
Wonder how it'll do with your carb set up better.
That torque number has me almost convinced to blow my whole upcoming bonus on the bike, which I really can't do.... In the midst of a house remodel...
I'll have to settle for ordering Gold Valves for my forks.
Jeebus, I just noticed the test temperature! It was barely 50º here today, I need to move...

 

I gained 1.5 hp from stck carb to pumper. I think with cleaned up head 33 is very realistic

 

BB351 on stock bike -


You have more HP/TRQ than I would have expected. Your AFR chart shows all the way down to the 11's. But those rich numbers occur after peak HP.

 

Yeah. But my early off idle range is super duper lean, which is how Ive been getting 65mpg cruisin at 4k rpm. Is the bike supposed to be able to pull well full throttle from 2.5k rpm? That seems real chuggy to me..

 

28/23 seems like great fun to me! That's sweet!

 

My bike (mostly) stock pulls from 2K up, it just ain't purty.
The torque line seems perfect for me, it starts ramping up around 3K!
I've had numerous trail situations where I've been chugging along almost to the point of having to slip the clutch (which I've had to do as well, but not much), so a nice torque result, starting low will be good for my type of steep and rocky trail riding.

 

Yeah, the problem on the dyno was around 2k in 4th gear he would go WFO and it would just cut out from being so lean

 

 

Neither of the SR500s nor my 650 will pull cleanly from under 3000 rpm. Everything I've ever seen on singles indicate similar results, regardless of displacement. It's just too low an rpm for the level of tune of a motorcycle engine (cams, carbs, etc making for a high performance engine). I remember one hop up on an SR500 build had it bucking on the dyno when hit hard at anything under 3000. My own riding experience backed that up, jerky response.

I would never expect a 250 to pull cleanly from there and based on your chart yours should start strong closer to 4000. Your jetting will probably get it stronger down lower, but 2000 - too low. My 83 GL1100 wouldn't really pull well that low, nor did others. Honda's response when we asked for a customer who complained about his Wing chugging and struggling when opened up at 2500 in a high gear - designed to pull strong starting at 3000-up, best mpg 3000-4000 rpm.

You're definitely influencing me to go to 351 before carb... great stuff!