TM36-68 hanging idle
 

The '06 with 351 kit got a TM36-68 this winter. Jetted per my sig line. Air box lid off. Initially adjusted pumper to start squirt at 1/8 throttle opening (the squirter just barely hit the bottom of the slider as it was rising) to 3/4. When not fully warmed, if I whacked the throttle open from idle, it would bog, even die. So, squirter adjusted to start a little sooner and it helped. Went for a trail ride last weekend and it was nice except for a little hanging idle with throttle closed.

Rode around town yesterday with it fully warm and noticed the hanging idle more. Throttle up, go through a few gears and let off the throttle and the idle would hang, indicating a lean condition. If the throttle was blipped during the hang, it would drop right down (a squirt of fuel). It doesn't do it cold, only warm. I'm thinking this is a lean condition and the pilot circuit needs to be enriched a little.

I will put the air box lid on and try it again to see what difference there is. Wanted to throw this out and get opinions on any other possible issues before I enrichen the pilot circuit.

Neither cable or the carb appear to be hanging up from an exterior inspection.

Aside from this little problem, jetting seems to be pretty good and I'm liking the pumper! A longer throttle cable is needed though as the play with handle bars forward and to the right is too much, and full to left has just the slightest amount of throttle play. Rox 2" risers (thanks Mark) and bars may be just a little taller than stock.

Scott, have you gotten aggressive with the fuel/air screw? I'd think you could test your lean theory on the idle circuit by going as far in as a half turn from closed to 3 turns out to see if you get a different condition on the hanging idle. Might idle like crap but you might be able to get a decent diagnosis of rich or not as it applies to the hanging idle. Yes, the fuel/air screw is decently hard to access when warmed up. I gently use a needle nose plier on the serated edges of the screw, and it's worked without buggering up the screw...at least as little as I've had to putz with it.

You're right that a hanging idle is most commonly a lean condition in the pilot circuit, but I'm still curious about your throttle cable and linkage issue you had during initial assembly. And with your mention of the cable tightness, I'd still keep the cable smoothness as a possible culprit. Knowing you, I'm pretty sure you've eliminated an air leak already.

Odd the idle hang started after you adjusted the squirter but evidently hadn't touched your idle mix. Hope it straightens out for you. That's the 2nd TM36 hanging idle thread recently.

I can adjust my idle mix with a hand on each side of the carb, but if the engine's hot I'll use an old hacksaw blade with each end bent at different angles.

I might spring for one of those 90 degree MotionPro carb adjusters if they respond to my asking them about the minimum space it'll work in. (will it clear the starter..)

Thad and Richard,
Thanks for the replies.

I haven't checked either an air leak or the mix screw. Only thing adjusted was the sqirter to see if the setting was the issue. The boot is tight, but I will check for air leaks. And then will check the mix screw after that. I looked very carefully at the carb wheel to see that the cable wasn't hanging up and pretty sure that's not the problem.

The hints are welcomed. Thanks again.

Try propping your tank up a few inches-moving it away from any cable clearance issues and see if the idle still hangs

I noticed when I added the Acerbis tank that the side clearance on the bell crank and the sump was causing some interference. I had to do a little grinding on the upper cylinder mount bracket on the frame to allow me to rotate the carb an additional couple of degrees to get it all lined up.
Something to look at...

I've got it solved. It appears that when I had the carb mounted I had it tilted a bit more towards the fuel line outlet on the tank than normal, throttle wheel was hanging up just a bit on that. Good news is tbat I'm back to 55mpg.

Yeah, I completely removed the return pull cable segement of the throttle wheel on my 36 under my Acerbis tank to insure full clearance. I'm pretty sure Scott has already modded his in similar fashion.

Adjust your pump so that it comes on right away. Works for me. Good Luck, Later.

I did.
It didn't work for me.