Ok, If they are same as DJ136 and DJ138 , they should be perfect..

It's not brands, it's the internal design of a Quiet Core 4 vs the straight thru That-Bad-Boy-Belongs-in-Jail DG-R I use ....

Wheelie vid is stock sprockets - I have always run stock sprockets.. I'm naming my next kid "Sprocket"..Boy or Girl..

 

If klxster throttle wheelies with 14x42 I should have fun using the ordered 13/14/15x43 sprockets on my 17" wheels given I've done the same mods with similar torque output. I like 15x39 for commutes but want hooligan fun on my days off.

 

Snappster, you can't pull 1st gear throttle wheelies with the 15 tooth ? I really believe your loosing the sharp TRQ rise from idle to 6.5k by running 4N on that DJ136.. But 95mph, holy grunt cakes batman..

 

You guys do realize power wheelies are dependent on more than just power when on a small bike, right?

Where you are sitting has a big influence. I tend to sit up against the tank, so not too conducive to power wheelies. Going on a dual sport ride this weekend and will goof around a bit with the 13/47, although I know it works well on trails with little clutch slipping.

Even the 650 doesn't power up with a snap of the throttle the way I sit on the bike. I will say the 650 can ease away from a stop with a bit of strong throttle as the clutch is let out - definitely power putting the wheel in the air. If I could ride wheelies and shift while in the air it would be a case of how far you want to go.

 

Thanks for the suggestions. Had a chance to try more combinations with the parts I have on hand. Tried removing the airbox lid which helped some, but was just too loud. Also tried going to 132 w/ the stock needle, 132 at 2N, and now back to 128 at 3N. Unfortunately the rough spot at 4.5K to 5.5K at WOT remains. Some of the combinations above are slightly better than others, but none have gotten close to eliminating it. Very frustrating as the bike was jetted quite well before the MCM, and now I'm back to the same jetting and still have the issue. And that's obviously an engine speed that gets used frequently, so I need to figure out some way to clean it up.

My next thought is to try the stock spring with 128 @ 3N and see what happens.

Also, after having the carb out again and checking out the "choke" or enrichment circuit operation, it appears that it just allows the intake vacuum to pull the slide open earlier and must pull fuel through the main jet? Not totally sure on that, just a guess. But if that is the case, it explains why pulling it while riding seems to do nothing, as the slide is already fully or almost fully open.

So who has done the MCM but still runs the airbox lid (no snorkle) and some type of aftermarket slipon exhaust? What jetting did you settle on? In summary, I'm currently at 2152 needle and spring, 128 @ 3N, stock pilot @ 3 turns out, <1K' ASL, and getting a nasty surge/sputter/etc at 4.5K-5.5K RPM. Below that is clean, but not particularly strong, and above that it pulls well up to 9K RPM or so (tapers off before redline now, likely a result of the MCM, as expected).

 

I don't have the exhaust on at this point, but have the KLX300 jetting and Dial-A-Jet in my bike, no problems and even with the 13/47 gearing I'm seeing 50 mpg which I don't see as too bad when reving 7000 rpm at 60.

I didn't have any problem staying with my brother on his 06 with same jetting plus a full KLX300 exhaust without the butt plug that makes for a pea shooter. He made a decent size down turn on it. He doesn't have the MCM. We didn't get to swap bikes. It pulled the stupid high 15/39 running easily and hard up to 75 mph, holding 70 easily. Even then it seemed to lug down really well for a small engine.

I do not quite understand the big need for jetting. I did both at the same time. Maybe because I'm running lean on the jetting brass and, as expected, the Dial-A-Jet is supplying additional fuel to fill in. The only place it does not work is at idle when the slide is closed.

 

Thinking out loud again Snowdrifter..

Your problem seems unrelated to main jet/needle/clip position setups.. All of those combinations you used work perfectly well - just don't offer the best power levels, especially at 8k-Redline..

Since pulling the lid helped - probably using the stock needle did too - you are, in fact, getting a "fuel dump" during, at least, needle operations.. Seems something is broken or not installed correctly..

You certainly would not be the first, nor the last, to have inadvertently borked your carb during a simple setup change.. Float system fubar'd, needle not installed correctly and/or not sliding in and out of needle jet, diaphragm damaged/leaking, clogged this or clogged that, etc etc..

But again, I'm just thinking out loud..

 

No it would not allow the slide to open faster. It simply adds a tiny amount of fuel/air mixture, to slightly richen the mix. It is a totally separate circuit, pulling air in at an orifice in the bell mouth end of the carb, feeding through a tiny hole by the throttle butterfly. Not positive where it is pulling fuel, but I am pretty certain it is not through the needle jet area.

I used the enrichener to see if the added fuel mix would stop or soften the surging I had when holding steady rpm around 6000 rpm when running a shimmed stock needle. It did pretty much eliminate the surging on steady throttle at 6000 rpm. This was how I found I needed to just go to the KLX300 needle, the mix was too lean to compensate with the Dial-A-Jet.

 

Yeah, I was mistaken. After thinking about it more, pulling the enrichment lever exposes the area under the slide diaphragm to the carb's outlet, which would seem to help force the slide down, not up. Also, it must mix that air with the fuel drawn through the starter jet down in the bowl. Found a diagram:

 

Thanks for the ideas. Will dig into it again when I get a chance. Can't think of anything that might be broken. Specifically inspected the slide diaphragm looking for tears, but looks fine. Will try giving it a thorough cleaning, but given the fact it seems to run OK in most of the RPM range, I'm not optimistic that it will help. The bike starts great, and carbs OK at partial throttle, but full throttle over a small rev range is the only issue. Unfortunately it's a big issue, as that's a speed/load that's used often. Very frustrating. Thanks again for all the help!