I'm kind of wondering about this. My KLX was kind of hard to start if it sat for 3 or 4 days. I had to crank it a bit with the choke on to get it started. However with the aftermarket pipe on it, a #40 pilot jet, a #128 main jet and the N1TC needle with the clip in the 2nd slot from the top, it just starts up on the first revolution. I have not started the KLX since Sunday. I just went into the garage to see if it would start with no problems and it almost made a full revolution before it fired right up.

Anyone else notice this, or am I just hallucinating from an overdose of L-tryptophan?

 

id imagine it has more to do with it getting proper fuel flow since their so choked mixture wise from the factory... just a guess tho.

 

I was a little concerned about there not being a choke on the Keihin FCR, but when I got home from vacation after my bike had been sitting for a week and it was cold out I just twisted the throttle and held it for a few seconds to give it a little squirt from the AP, pressed the start button and it instantly fired right up. I've been too long with the Muzzy to remember what starting was like with the stock pipe, though. I certainly can't imagine it starting easier than it does though.

 

I think jsac is on the right path. Your exhaust should have very little to do with it, since most of the vacuum being produced to draw the extra fuel out is happening because the choke is closed; not because of any increased air flow velocity that the exhaust would induce through the carb venturi with the choke and throttle plates open. Having the choke closed will allow fuel to be pulled from your more-open-than-stock needle valve and your larger that stock main jet at a very low RPM. Any effect from the more free flowing exhaust would happen with the throttle plate being open at higher RPMs.

"Eshasut" ??? [8D] Yeah, you might want to back-off on the L-tryptophan

 

Well when I first got my bike, which was a year ago yesterday, I had trouble starting it in the colder weather. After getting it jetted to the 40 and 132 jets, and the Muzzy, all I do is pull the choke, and hit the starter and it fires right up. However I do know if the bike sits for a few days it takes longer to start. My wife's bike is way worse, in fact the mechanic where I bought both bikes told me if I jetted the XT 225 it would have no problem starting. I wonder why time affects starting? Is there a place where gas is evaporating? Oh well I'm getting ready to order the jets for her bike, I think the pilot is like $4.25 and the main jet is $3.99. If it works out and starts easier I will be ordering the same jets for the 2003 XT my friend has stored in my garage.

 

Hey, I had just washed my hands and couldn't do a thing with them!

Now, my KLR650 has a Keihin CVK40 on it and even if it hasn't been started in about a week, all you do is put the choke on and hit the starter. It's running like right now. I have noticed on the KLX that if it sits for almost a week, why it takes a long time to start. But after the exhaust slip-on was added, it just started up immediately. And it was colder than normal.

Last year at Tour de Apalachicola, I noticed that the bike was kind of hard to start in the morning, but it was in the 40's. Of course that was before the "Grapevine Mods" and all the jetting. I'm betting this year there will be quick starts each morning.

I'm hoping to here about my Mikuni TM33 sometime this week. With an accelerator pump, I should be able to crank on the throttle and then touch the starter and have the bike start right up.

 

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Yeah, well I gues what I was getting at is that with the choke closed, the choke point (no pun intended) is now at the carby rather than in the exhaust. The exhaust will have no effect, but the larger main and needle jets certainly will. You'll get a nice, rich start..just what the doctor ordered on those cold mornings.

Oh yeah! PUMPERS! I can't wait to hear your review!

I will soon be buying what is basically a TM-34 that has been modified by Yoshimura(TMR-MJN[Mutliple Jet Nozzle]34). The only major change is in the needle valve. Instead of having the normal, tapered style of needle that fits into at needle jet, it uses a hollow needle with several small holes drilled along the side. Fuel is supplied directly to the needle. As the slide opens, the needle gets pulled into the venturi exposing more and more holes for fuel to come out of. What you get is more and more fuel being directed down the center of the venturi rather than from the side as a convential needle and needle jet arrangmet would do. The result is better atomization and less sensitivity to altude or temp changes as opposed to a other flatside carbs. I have some friends who use them and they run suweeeet! Below are some drawings from the Yosh. Japan website that show what happen with the MJN needle (left) as compared with a tapered needle and jet (right). I will be getting the version that comes configured to fit our airbox, rather than the one with it's own filter. It also comes pre-jetted for the KLX/D-tracker.











I have a feeling a lot of people in this forum will be running with a pumper before long.

 

would a pumper reduce the longjevity of the motor? would there be any long term problems with running a pumper? just wondering, its a little out of my price range right now.. maybe in a year or two...

 

No, it shouldn't have any effect on that.