Whose post were you referring the 115 Mikuni jet from? On the issue of installing a TM36 on a pure bone stock KLX...why would anyone want to? Just curious.

 

He's referring to FlyingFinn's jetting work.

 

There's lots of confusion about how different manufacturer's jets relate to one another. Here's a couple of good articles for anyone bored enough to want to see how they relate.

Dynojet - Mikuni - Keihin jet sizes conversion - Ninja250Wiki

http://www.ozebook.com/compendium/t500_files/mikuni.pdf

The fascinating thing is that there is often no real correlation of how the numbers compare to each other...other than a relatively close comparison that gets you in the ballpark of tuning. If I understand correctly, Mikuni jets are the same flow standard among the different models and designs of jets in their lineup. However, that number is for how the jet flows...not necessarily how that orifice sized jet might flow in a different model Mikuni carb.

I don't know...what I'm stating here may or may not have any major influence on the discussion here, but we often discuss the cross-reference aspect of carb jets, and I found these two articles fairly informative in understanding the real differences and similarities in how carb jets are classified by size and operation.

 

I asked about the jets because I have a million DJ's laying around but no mikuni. After reading your links about how the companies differ in how they label jets, I'm just going to purchase for now mikuni jets for the tm36-68 off sudco.

Yea, trying out FlyingFinns jetting settings because I'm also at sea level. I wondered about a stock bike because with so many people having different mods to the bike how do you know the difference in intake or exhaust speeds and how that effects their overall jetting. Would be nice to have an estimated beginning point. As of right now my bike is bone stock. I need things spelled out because I'm no mechanic, I just love to ticker with my bike.

 

Got it. I wasn't challenging your idea of perhaps installing a TM36. I find this carb to be extremely tuneable, and after matching one up to my 300-jugged 250S, I have little doubt that it would work on a stock 250. While the 36mm bore is 2mm bigger and less restrictive than the OEM CV34, it also has more available tuning elements. It has three possible ways to influence the pilot circuit, has a better starter fuel circuit for cold starting, more available needle jet/needle possibilities, and a dramatically tuneable accelerator pump to fit most any application. Reading the Mikuni HS40 tuning guide is a great insight into this very capable carb...yes, it says HS40, but all tuning info is identical. And while those tuning elements I mention might sound complicated, they're really not. And considering that all the big, hard steps in setting one up for a KLX have already been done, the fine tuning is actually a bit of fun. And you can get this carb in and out of the bike for complete removal without a bunch of profanity and rubber hammers...LOL!

 

UPDATE. Just to pass along more boring stuff. Took off the snorkle competely, and tuned the air screw and idle adjust ****. Bike starts on first crank, choke is reduced within the first 10 seconds, throttle up in 20, ride in under 30. Now I'm no expert on rich conditions, but it seems a bit too good. Will check my plug again after a few rides, which is all it took last time to blacken it. Still, my settings don't seem that far out of line with you others, so I've got a bit of a head scratcher here...oh, well. The riding part is fun anyway.

 

Lilyboy,
Do you know what pilot air jet (PAJ) is in your carb? Mine - bought used and from a different application - came to me with a 1.2 PAJ, not the 'normal' 1.0. As TNC pointed out, a smaller PAJ has the same effect as a larger pilot jet. If you have a smaller than 1.0 PAJ, say a 0.9 or 0.8 in combination with your 17.5 pilot jet, that might cause it to be too rich at startup.

 

Mine has the 1.0.
I don't have a lot of time right now to futz with it, maybe this weekend. Too much kid stuff right now, but in a few days I should be able to check a few things out in more detail. Don't know exactly how far out my air screw is, but if it's close to 2 1/2, that should tell me to drop one in the pilot. I'll find out, hopefully.
Thanks for the reply
Sunday update. Took it out for a ride so I could pull the plug and check it out. Maybe a couple miles, then it died a block from the house at an intersection. Would not start again. That was it. Pulled the plug, same results. Carbon fouling, not as black as the last one, but this was after two short rides. Wondering if i have float bowl issues, since the jetting is just not that far off from everyone else. Carb really leans to the left, and tilting (the bike) just a bit more flows gas out (the overflow hose) pretty easily. Have to admit, little experience with float bowl troubleshooting. And since this one starts out not level.....? Wish me luck.

 

AND AND AND ????

he left us hanging

 

I have installed the Tm36-68 on my 2012 klx250s. I have a mix of this forums jetting choices and the results are very good. Some one on this forum said, "If I knew how much better this carb is I would have made it the first change I did to the bike. I agree. I'm having a problem. When I close the throttle completely (corner entry-hard braking) the slide closes down until it is contacting idle adjust rod. as it should. When I start to roll the throttle on (to exit corner) the slide is stuck. I actually have to give the throttle a little yank to get the slide moving. When I'm leaned over as far as I can going as fast as I can this makes the rear tire brake loose. This sucks. The bike is more forgiving than ANY bike I have ridden and it has not bitten me....yet. Anyone experienced this? It's probably vacuum. HELP! Thanks.