640 LC4 jetting, again...

So, I have been looking some info on internet, but there is something that I don't understand.

 

I'm running now -03 640 with Pro Circuit headers, Akra slip, open air box and FCR 41 MX

Setup now in carb is 175-MJ, 48-IJ about 1 round open, OBEKR needle second clip from the top (5# pos.?)

 

So incomprehensible problem is that when twisting thorttle fast to about 1/4 or 1/3 it cutsdown and bangs from exhaust #1 so is this bog?

 

2# Is it rich or lean?

 

3# How I solve problem?

 

 

My dad tried it few days ago (then I was running temporarily 190 MJ, because 175 MJ cuts half.) and he didn't pull full throttle but almost to the end. I always heard &%$#@!ing big bang when he decelerate.

 

So my conclusions would be: too rich? 45 IJ and needle clip leaner? maybe 180 MJ?

 

Thx

Ops, I haven't noticed that I have OCELM needle. Maybe OEM 450 crf?

And I tried to put needle 2 pos. lower and problem getting bigger, and easier.

So the problem would be here? Too lean on middle?

I go and get OBEKR needle today and try it...

it's no wonder that I cant get idle lener... OCELM is so rich in offidle-1/8

GRAAH jive.gif

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