So I have been in a small battle tuning my bike. When I ran it in CO, it seemed to be okay with a few mods and the Dynojet kit. Then I moved to Texas. I am roughly 2 feet above sea level. I have the snorkel removed, cam mod, KLX300 (four stroke works) header, Two Bros KLX300 muffler, and the same dynojet kit with a 128 main, pilot jet maybe 3-3.5 Turns out (can't remember) and it still won't start cold under 80degrees. Which seems wrong to me. And the needle clip is in the 3rd (middle) position, and the two shims are placed on the circlip. Dynojet spring as well.

So the thing still seems to pull pretty well at all RPMs, once warned up, but when it gets real hot, if I snap the throttle to about 1/4 open, like when leaving a light, it goes CLACK like a knock and keeps revving up like nothing happened. It also will stutter around 4.5k if the throttle is whacked open SOMETIMES. My biggest concern though is that since going to the KLX300 exhaust, the thing dumps a TON of heat. Like before I never noticed, but now on the highway at 70mph, my leg is getting cooked! And when I get home, the fan is running, which never happened before. I think the bike is lean, but I also feel a 132 is too much. My current setup is what Dynojet recommends but they had no idea what the cam mod did lol can anyone offer up their tuning setup?!

Thanks and much appreciated

 

If it ran well at elevation but now stumbles and detonates with heavy throttle, it indeed seems to be lean. I'm not completely sure how much the cam mod will affect this either...but...your description of performance at the two extreme elevation differences sounds lean to me at your current elevation.

When I ran the stock carb with DJ kit at my 1700' elevation further northwest in Texas, I ran the 128 DJ main, DJ needle in the middle clip, stock 35 pilot jet, and 2 turns out on the fuel/air screw. It ran perfectly. I'd say you'll need to try the 132 DJ main and perhaps even another step on the needle to richen up throttle response. A 38 pilot may even be in order.

That feeling of more heat may indeed be a result of lean running, but it may also just be some of our Texas heat building up as it does in June and July. On the hard starting, have you drilled the starter jet to .018"?...and checked the fuel level in the bowl?

 

I should have clarified, the tuning between CO and TX changed haha I meant I had my tuning correct in CO and retuned for TX when I got here. I really need a bigger pilot though.

Does anyone have a part number for the 38 pilot?

I ordered the 130 just now. I feel like the 132 might be too much but I'm not opposed to trying it. It just runs very good in mid and top range to me! Could it run better? Maybe Idk haha I haven't felt it run better before.

That heat though was never a problem with the 128 ND stock exhaust. Just stuttered at 4.5k since the exhaust, stutter is gone...

 

With the cam mod I am running a 132 DJ main jet and I am at 2000' ASL.

 

keep in mind that dynojet sizes are not the same as oem. if that 130 you ordered was a oem jet, its likely to be even smaller than the 128 DJ you have installed.

 

I did verify it was a Dynojet 130 of the same type. I found a conversation chart, but still opted to just find a Dynojet brand jet.

 

Kdick 91 - If you did not do (or do correctly) the ACR reposition during the MCM mod, your bike won't start well - Marcelino warned of this on page 1. For instance, not doing the ACR at all is hard starting cold and all but impossible hot. Correctly repositioned and starting is instant - Deactivated also reports instant starting.

If your carb is stock - pull the lid, use the #132 DJ jet, put the DJ needle one slot lower (raising it one notch in the jet) than Stage II directions, and your AFR will be 13 - 14.5 to 1. Still a little lean but over 1hp more than where you're
at now.

Cmott @ 2k with the standard Stage II needle setting and lid off is probably getting 12.8 - 13.5 to 1 AFR. Just about perfect.

 

I did the cam mod "correctly". By that I mean I disabled the ACR. The thing fires up if I just look at the starter, but when it's cold, it's very unwilling. So opposite if I left the ACR on.

I'm not questioning your judgement at all, please don't interpret it that way, but where are you getting your AFR numbers from? I'd rather be a tad rich if anything. I've always tuned my cars around 12.7-13.2 WOT on pump gas. I know that's a little richer than perfect, but it's always given me peace in this brutal hot weather.

Thank you so much for your direct advice!! I need to get this jet out of there. Its starting to miss at 8K....

 

I'm getting my AFR numbers from my dyno testing charts. Click my logon - statistics - threads started...

My bike is practically identical to yours in mods. The last dyno testing was the shoot-out between the full FMF exhaust vs stock header + DG-R. The AFR chart on this posting is #132 with 1 notch richer than standard Stage II and lid off.

It is hard to get enough fuel into a uncorked stock bore with the DynoJet kit if you run lid off and lower elevation. My bike - from earlier dyno testing - picked up 1 hp just by changing from the 128 to 132. But it was still way too lean - 15 to 16 ......

12.8 is considered best AFR for power - max torque production is richer still.

If your hard starting is a fault in the carb circuitry , clearing that up would improve performance but only to the extent possible with the #128 's AFR.

Good Luck

 

Dang! So would it be worthwhile to get a 134? They are dirt cheap and easy to get.