JD Jet-Lag... (long, sorry)

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  • radish150

Posted June 24, 2005 - 10:23 AM


Ok, now that I´ve realized that I couldn´t find my little AC pump rod cuz I took it for an ALLEN WRENCH... (doh!) and put it in my tool box. It´s now safely installed in it´s intended place. Now, on to more current disasters. So I shall try to keep to the facts here.

The prior condition of my 99wr400 was a bottom end with no bog, a decent midrange power (uncorked), and a sick top end with a high speed misfire (falls on it´s ass).

So, I´m thinking JD kit right? I´m in a humid climate with generally high temperatures so according to the instructions I go with the red needle in the forth position down, and the smallest jet (i forget.. 160? 165?). My old main was 168. So I start it up with the new billet exhaust insert. Will hardly run, dies. Take out the exhaust insert... runs better but still bad. I move the needle up to the recomended third position and it runs better. Put the exhause insert back in and it dies when you goose it. So I take it out and it´s better again. So, next I see that my zipty needle has little or no effect on ANYTHING, so I set it at 1.7 turns and go for a run.

BUT.... before i get ahead of myself I should say that I also changed my AC diaphram in the rejet process. I could not get one where I was, and when I amputated my octopus I took apart that little removed diapgram canister and saw a bright shiny new diaphram in there allmost.. haha, like my old cruddy one. So, i sawed the nipple off to the right heigth and stuck it in, despite the fact that it was indeed a bit differently configured.

So, I set out for my first spin and first thing I see is it will hardly run when accelerating off idle. It idles ok, runs ok at any STEADY low or mid rpm, but when accelerating from an idle it litterally chokes and will die and takes forever to start with the hot button pushed. The choking is terrible when rolling on the throttle from a start, i nearly had to push it home. And.. to boot, the damn high speed miss is still there, maybe even worse. So, is this likely an extreme case the dreaded BOG that Ive heard so much about but never experienced? Caused apparently by this slightly different ac pump diaphram? As my grampy used to say... I got a ¨stinking hunch¨that thats it. So, my plan I guess is to pull the ac pump rod for a run and see if the bog goes away. At which point I will still have this issue of the persistant high speed miss, which actually seems a bit worse do to the smaller main jet? Could it be I really still need to go up on the main jet size? Im at sea level for god sake, but maybe.

So, what do you guy´s think? Was the red needle the right one (hot and humid)? and in

Ill bet when i get the ac pump back into it´s former lame condition the bog goes away, then ill just be left with the high rpm miss. To be fair, the midrange feels excellent when I can get it past the bog.

I think they should put an icon up here that shows a guy down on his hands and knees praying to the thumper gods for help!!!

thanks peeple
mark sheldon


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