KLX140 carb upgrade, Mikuni TM28 flatslide 

John, I live just south of Memphis and have a 140g. Can you tell me what worked best for you? I have a FMF slip on and the rest is stock, but it pops.

@@travislinton7258 I’ll have to look to see what jets I had in it. I’ve since put a 170 big bore and changed my carb to a vm26. For whatever reason the vm28 ran fine with the stock piston but when I put the big bore on it wouldn’t run right. So I put a vm26 on and it runs awesome now.

@@johnhancock1855 Hey John, what jetting are you now using with the VM 26? Mine came today with wonky jets preinstalled (45 and 135). I've done airbox mod, have a pipe and will install 170 kit and cam in a few weeks. Thanks!

@@Thedestressguy I didn’t install the cam with mine. Stock head and stock cam with an fmf slip on 170 Bigbore kit. I’m in Memphis TN and my current jetting is 185 main 15?pilot and clip in the middle. It’s been flawless for almost 20 hrs without 1 hiccup. I’m eventually going to out the sxparts race head with the cam on when I get a chance but almost don’t want to mess with it because it runs so good.

@@Thedestressguy oh yea. I removed the snorkel and drilled 3holes in the Airbox lid.

i Am using a BBR heavy duty shock its a big difference

I had to make a gasket, used gasket paper and gasket sealer on both sides. The throttle cable was straight on ours too, It gets bent to match the curve of the gas tanks underside. The macaroni style cable guide on the carb top would have been a better option, but we had no issues with parts as delivered from EO.

@@millertimemoto64 Having a little trouble getting the intake hose from the airbox to fit on the carb. The oem carb has a slightly smaller diameter than the Mikuni. Briefly tried getting it to fit with no luck so far. Will try again tonight. Thinking about using the K&N pod filter and removing the original airbox but that is what holds the battery. Trying not to overly mod the thing.

Put some isopropyl alcohol in a spray bottle, use this as a lubricant. I’ve got a blunt tipped 90 degree pick that i use to get the boot onto the carb body. Point the picks tip toward the air filter and feed the boot onto carb body by running the pick around the carb inlet.

Thanks for that tip.

Alcohol and the pic did the trick. I ended up removing the airbox and installed it after the carb and airbox tube was all connected. I installed the included cable and there was enough clearance under the tank. Briefly fired it up in my shop and gave it a few quick revs and without any adjusting, it is obvious the bike it more lively. The exhaust even sounded better! Cant wait until tomorrow to take it put...

The engine is stock, with the exception of the Procircuit exhaust. Regarding the 26 vs 28, the Engines Only kit came with the 28mm carb. For a stock bike, smaller is probably a better option. I was looking for a plug and play option, hence the purchase of the kit.

@@millertimemoto64 Thanks for the update :)

You need to go bigger on the main. It’s counter intuitive, but with the smaller bore engines, the “signal” decreases as the carb bore increases. At WOT the bore is at its biggest, the velocity of incoming air drops, decreasing the “signal”. You need the bigger jet to compensate for this. Jets R Us will have what you need.

I thought the carb was a VM-28 but now realize it is a TM-28. I did lovate the jsts at jetsrus and have ordered a 220,230 and 240. Leaving to go on vacation and have the bike running good enough for my riding style. When Ibget back, I will start trying to calibrate the carb. I did learn that it does not like the needle at the highest postion (clip at lowest slot). It sputtered at 1/8 throttle. i stayed with the factory pilot and have the air screw at 2 turns out so I think that is pretty close. Thanks for your input and help!

that is not normal at all you need to get that fixed and serviced with new fork oil

Franks kit comes with a different intake manifold, K&N pod filter, and jets suited for the KLX.

Frank at EO is more of a phone guy, might have to call him up to place the order. I sourced the 220 main, it was not included.

Yep, he seems like he would prefer talking but I was able to get the carb ordered and tracking shows it will arrive in Wednesday. He said he threw in a couple of extra jets in with the order. Wednesday is so far away!

down

@@tonemiester Dear baby Jesus, I just spent the last few months trying to tune it while choked. :( Crazy thing is that I have it dialed it pretty good. If I am correct, the choke setting should only affect the idle circuit since it is not utilizing a butterfly valve so I should not have too much of a night mare. Thanks

@@tonemiester So to clarify, the "choke" plunger should be up or out of the bore for the choke/fast idle mode. The piston should be down or in the bore for normal operation. Some carbs have a lever to move the piston, some simply have a knob attached to the choke plunger. With the lever system, the action is opposite of the plunger. With the lever down, the plunger is pulled out this allows more fuel and air through the idle circuit for cold starts. With the lever in the up position, the plunger is pushed down and closes off the additional fuel hole. The video linked has a great explanation and the Mikuni system is around the 5 1/2 minute mark. Thanks. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Di-v06bnXYU.html

The upgrade was win, however it is not without fault. As mentioned in the video, the vacuum under engine braking pulls the slide into the carb body. It takes a bit more force to move the slide in those situations, this "feels" like more effort required at the grip. The throttle pull variability (idle vs engine braking) was noticeable to my wife and took her a bit of re-calibrating to get used to. It makes more power off idle and the delivery is more abrupt, so it rewards a rider that has mastered clutch control when riding Pacific North West slow tech.

What was your final jetting setup?

See description above.

@@johnhancock1855 were you able to get ride of the bog? I'm running into the same problem. My spark plug is telling me I'm rich though... starting to think the 28mm carb is just too big maybe for good a ventri through the carb.

@@dtr_downtoride I agree. I ended up installing a Mikuni vm26 carb. Ran excellent once i got the jetting right. I have now since installed a 170bigbore with an aftermarket head. When I first installed the big bore I put the 28mm carb back on and I couldn’t get it jetted right. I then put the Mikuni 26mm back on an it fixed it. I’m convinced the 28mm is too big for the motor regardless if it’s stock or big bore.

I believe it's the protaper contour mini high bar.

I can not confirm that. I purchased the carb kit from Engines Only, xr100.com. The kit includes the manifold, carb, and cable.

Millertime moto I ordered the kit from Enginesonly because of this video. I should be receiving it any day now and can’t wait to install. I’ll report back on how it does. I was at my witts end with trying to jet the stock carb.