I pulled the trigger and bought myself a late birthday gift and it arrived today, a nice shiny pumper carb. I got it bolted up in a jiffy but found I needed a few minor adjustments.

1 The main jet's cap is hitting the starter (need to turn the nut)

2 Bogs when you whack the throttle (moved clip to 3 adj, pump timing)

3 Seems to want a bigger pilot jet

4 Throttle is sticking a bit

5 Neighbor said it sounded louder so he came over promptly!


After messing with the cool new ***** and screws it smoothed out a bit and I"ll have to re-route the throttle cable under the wiring but I do like the new "Power Now" option. So far it seems smoother than the stocker I hated the lag and the erratic off throttle response. Could have been a jetting mistake on my part but I liked it on the rich side.

If anyone's got a link to a good tuning manual I would appreciate it. The little graph on a card they sent me is a bit to barbaric to make any sense. If you want to throw out a good baseline jetting I would love to hear your opinion. My ele. is 600ft and the rest is in my sig. I did get a few jets with my order 10, 15, 125, 135 and I adjusted the squirter to hit the needle although it misses a bit if you gently tap the throttle from closed.

 

"2 Bogs when you whack the throttle (moved clip to 3 adj, pump timing) "

How did you adjust the AP timing?

[edit]
Sorry I can't read. I incorrectly assumed you got yourself one of those TM33/34 carbs. Those do not have adjustment for AP.
But after looking at the picture of your carb I realized you must have the 36.... which you said in the Subject line but I missed it.

 

You got a pic of it in the box.... but not on the bike?

what a teeze....

 

Congrats on the new carb! Here's the Mikuni tuning manual. It's for the HSR series, which are the same carbs, just bigger: http://www.mikuni.com/pdf/hsr_tuningmanual_021003.pdf

This is my jetting at 2400' ASL:

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 (fuel should splash off of
the needle)

At 600', you might run a tad rich, but try my settings first, then go from there. Note that my needle and needle jet are different from stock.

The main jet cap hitting the starter and the sticking throttle can be cured in one shot. Tilt the carb just enough in the manifold so that the main jet cap clears and the throttle wheel doesn't rub anything. It's OK to tilt it just a bit. If your running the stock tank, you should not have any problems clearing the throttle wheel, but if you have an aftermarket tank, you will have the grind the top part of it off.

The easiest way to adjust the AP is to take the carb back off. GENTLY twist the AP squirter so that fuel splashes off the needle (this is important, because you will get an incurrable part-throttle bog if it doesn't). Then adjust the AP starting point so that the stream just clears the throttle slide and hits the needle when opening the throttle. Face the carb away from you when doing this, and keep the fuel bowl full with fuel or carb cleaner. Then set the AP stopping point at 3/4 throttle.

If the engine is idling and you whack the throttle WFO, it will bog no matter how well the AP is set up. That's just the nature of the beast. In real-world riding, you likely will never do this, so it doesn't matter really. Worry about bogs or lean surges that occur in the RPM range you will be riding at.

Good luck and enjoy!

EDIT: I forgot to mention that I'm running a K&N filter with the airbox lid removed. There is a big difference in power between leaving the lid on or off, so I left mine off.

 

Hey guys
Can you use this manual to tune any carb. ie the CVK?

 

Just thought I would add another AP timing technique to the below. A good rule of thumb for the KLX is to have a one-second-duration squirt. The easiet way to check this is to remove your carb with fuel still in the bowl then whack the throttle fully open while recording the squirt with a video camera. Play back and note the time difference between start and stop of squirt. This should be one second. Play with the second AP adjustment (3/4 throttle AP stop) to get the duration as close to one second as you can. If unable to get within spec, a different size of leak jet may be required.

 

Thanks for the tips/info guys.

I fixed the sticking cable for now, threw in the towel while trying to tune the pilot jet and ended up going for an actual ride (beyond the driveway). I am amazed at the difference already no more rubber band throttle response and the bike pulls harder all over the rev range. It's breaking up a bit at low throttle (need to do the witness mark trick) but I like it a lot.

My squirter misses the needle if you gently apply the throttle for the first 1/3 of throttle rotation after that it hits it. A quick WOT will hits it's mark. Is this normal or did I get a faulty squirter? I'm curious if this is adding to low throttle break up?

 

Update with Q's.

I followed everyones advice and got the p4 jet and 50 needle also got the 51, I'm running a 17.5 pilot and a 135 main (for now) double snorkle's, the nasty flat spot cleared up but it still lurches just as you crack the throttle even if I "lock out the pump". What is up with that? And my squirter is hit or miss, if you give it a second between squirts it hits it a double tap misses.

Ordered from Sudco this time and there web site blows so I listed the # for my parts. Don't order the pump squirter's for the TM 42 cause they are way to tall.

P-4 jet-003-654 $15.75
50 needle-007-105 $14.44
51 needle-007-106 $14.44

 

These are waht I have my 36mm set to:
Main Jet 130
Pilot jet 15
Needle Jet 568-P8
Needle 9DZK6-50
Clip in middle slot
Float Height 20mm at highest point.

You should also set when the accelerator pump starts and how long it squirts.
I have mine set to start squirting as soon as the throttle starts to open and the duration is set be best throttle response.

Ride on
Brewster