I have my 350 kit installed, and so far I've ridden 85 miles on it, breaking it in gradually. I am using the stock carb and the stock pipe. The generally agreed upon easy mods, the Dynojet needle, a different pilot and a different main jet. No screen and the KDX snorkle.

I sorted out the jetting, so we have baseline numbers to start from. Off road, where I'm using 4K-6K rpm, it's a beast. No, it's not a Husky 650, but compared to the stock engine, it's a different motorcycle entirely.

I will run it on the dyno, to see exactly how close it is, and to make any final adjustments. With my experimentation today, I have it very close.

 

Great thread in the works here.....

Cant wait for more reports....Im sitting on a jug just waiting for some good stats...Rpm range and power....Yum...Yum

Rocco

 

100 more cc's with the same stock small diameter pipe, doesn't seem like it would have enough diameter and cause a restriction. Any other comments on that?

 

IMHO you're dead on. As poor of a flowing pipe we have stock, with 100 more CCs of air being displaced, the stock system is probably woefully undersized. Same would go for jetting. Larger displacement needs more fuel to combust. So it would run leaner with just the bigger displacement.

I'm no expert, this is just what I've heard from wrenches and people here. Really curious to see a dyno sheet after proper jetting is completed.

 

yeah, I agree. with the same straw sized exhaust and the same oem 118 main jet, the dyno results will be pretty much useless. I would think the power one gains from a full exhaust, jet kit, hi-flo filter, etc. on a stock sized jug would be pretty close to the power gains the 350cc kit provides on an otherwise stock motorcycle. the torque will be higher, but horsepower probably won't be more than 23-24 horse. the exhaust/jetting is the main component on the KLX to provide power. I believe someone had got 23 rwhp with a full BigGun system exhaust and other common mods. I think that dyno is posted up here somewhere, like 2 years ago I believe. The Muzzy wasn't far behind. I don't think this 350cc kit's potential will be fully realized/utilized until a larger exhaust is installed- meaning full header and muffler, not just a slip-on as well as a larger main/pilot jet. I'm sure someone will argue with me though.

 

I'm using the stock carb and de-restricted stock pipe with Bill Blue's 350 kit.

The difference between the 250 and the 350 using identical carbs and pipe is amazing.

My carb isn't using stock jets. Using the dyno, I'll be able to get the jetting spot on for this engine configuration.

My engine is a test bed for several configurations, in the interest of helping people.

 

I don't know if you and Bill have been properly thanked for all the work you've put into this new mod and all your findings to date so here ya go...........Thanks. Please ignore the naysayers and keep on with what your doing. We really do appreciate it.

 

Clearly, it won't produce as much power and torque as a full race set up. If it runs well, then it's useful.

 

my bad, I misspoke. I didn't realize you changed jets. this naysayer still says you need an exhaust to fully utilize the added displacement but I assume you guys know that. the baseline will give you a number to build upon with an exhaust. modded oem pipe or not, the oem header is still too small for even a 300cc engine let alone a 350. Roeseler himself says that and he used to race the KLX professionally. A Muzzy is about the largest aftermarket header available I think. looking forward to the dyno results.

 

I would like to see your results too. Keep on adding on the modifications w/ pics if you could.

I seen a 35 fcr w/ taffey mod & hot start w/ assorted jets on TT for sale. It couldn't be cheap but I'd like to see the hp/torque that 350 would make with that carb & decent full pipe system.

Thanks for posting about the 350.

Can anyone elaborate on the 'taffey' mod?