Since the big bore will be next years project I thought I would start watching fleabay now for a carb deal. Has anyone compiled a list of pumper carbs that will work? I 've seen the Keihin 35 and the Mikuni 33 mentioned, but what else is there? Are we basically looking for a pumper carb for the klx300 or the klx/drz 400? Is a Mikuni 36 too big?

 

I think a dude in this forum that goes by 'Mustang' put a TM36 in his and likes it. You'll have get with him for specifics.

 

I'm that dude. Yes, a Mikuni TM36-68 carb will fit and work well. You can see how it fits here: https://www.kawasakiforums.com/m_155567/tm.htm

After a lot of trial and error, I finally got it jetted spot-on for my elevation (2400' ASL). My currentsetup is:
[ul][*]Main Jet: 130[*]Pilot Jet: 17.5[*]Needle Jet: P-4[*]Needle: 9EBY1-50[*]Needle Clip: 3rd slot from top (middle position)[*]Fuel/Air Screw: 2 turns out[*]A/P Pump Timing: Starts at 1/8 throttle and stops at 3/4 throttle[*]A/P Squirter: Pointed directly at the needle[*]Airbox lid removed - K&N air filter[*]Full aftermarket exhaust[/ul]
The secret to the jetting is the needle and the needle jet - until you changethose 2 itemsnothing will cure the stumble you'll get when closing the throttle. I've tried a 20 pilot jet, but noticed no difference other than poorer fuel economy. A 15 pilot is just too lean with this setup.

What I like about the TM36 is that everything is adjustable,includingthrottle spring tension andA/P timing. It's also a little easier to get in and out than a TM33. You'll get very good bottom end snap, andbig mid-range and top-end power. I had aTM33 (bored to 34mm) previously, which gave the same orslightly better bottom end, butit fell off in the mid-range and top-end compared to the TM36.

If you're running a Clarke tank, you definitely will have to grind the top of the throttle wheel for clearance, but it's not hard to do. Mine fit as-is with the stock tank, but other guys have had the throttle wheel hit the stock tank as well. 10 minutes with a Dremel solves the problem.

 

"The secret to the jetting is the needle and the needle jet - until you changethose 2 itemsnothing will cure the stumble you'll get when closing the throttle."

I have hearda fewpeople reportbig improvements tothe TM33/34 mid-to-top end by finding the right needle and needle jet combo,but I doubt it would equal that of a dialed in TM36.

Isn't it nice having a fully adjustabel AP? Here's the adjustment on my carb. You can see the end of squirt adj. about midway up the slide and start of squirt adj. on the bottom lobe of the black cam.

 

On a TM36 (the carb on the left), the green arrow points to the screw that adjusts thestarting point of accelerator pump action. The red arrow points to the screw that stops the accelerator pump. You can't get to the stop screw unless you remove the tank, but you can get to the starting screw with the bike together. I've even adjusted it out on the trail.

The TM36 also comes stock with an externally adjustable fuel/air mixture screw.The big nut on the bottom of the fuel bowl covers the main jet. You can change the main jetwithout even taking the carb off of the bike - just twist the carb and remove the nut.



I looked high and low for a different needle for my TM33 and couldn't find any. I even called Sudco (who were less than helpful), and they said that even though I might be able to get different needle to fit, they had no idea which one to try. Carb Parts Warehouse helped me out with aQ-0 needle jet, but they were also only aware of the stock needle. That didn't completely solve my jetting problem,so I wentto the TM36...

If you know where these guys are getting different needles and what needles they're using in their TM33's, please share.

 

Cool! The big redplug at the bottom of my bowl does the same thing (main jet change).My pilot screwis a bugger to get to though.

Yeah, I'll look around for the TM33/34 info. I don't remember off-hand where I readit, but it was a dumb move not to add it to my favorites.

 

Thanks guys. Given that there is only 4 dollars price difference between the two carbs it sounds like the TM36-68 is the way to go (less hassle). Anyone know what the equivalent carb(s) for Keihin would be? An interesting side note, when surfing Keihin web-site I noticed that they recomend a 37 mm carb for bike 250-375 cc. If that's tru the sock carb is way under-sized.

 

Great post and pics Mustang Thanks

 

That would be the very popular Keihin FCR35. Nobrakes had very good results with his and the people at thumpertalk swear by them. Not as adjustable as the TM36 though. You need to add a collar to the accel pump shaft to get it dialed-in...otherwise known as the 'Taffy mod.'

I think Keihin is thinking about MX use whenthey say 37mm for 250cc.

 

Hey Mike,

Thanks for the TM36 setup numbers (to be used as a starting point). I've had the alternate needle jets, pilot jets and jet needles on the shelf with the carb, waiting for a free weekend (when I'm not riding) to get it dialed in. I agree, the stock NJ/JN just doesn't do it (drop out on de-accel).

I have the 9EBY1-51 needle as well - it's a tad leaner. It's possible that may work better for me due to my altitude.

With the 17.5 PJ, were you able to get the lean and rich stumbles during adjustment? With the stock setup, the rich stumble just isn't there.