1173 needle?

[kaw Bill]

What's up with the R1173 needle? Is it richer? leaner? different taper. If i run it, should I go with the same clip position as my 1174?


Kaw Bill

 

[canyncarvr]

You're in for a treat!

Evidently you've never been to CDave's site? Go to:

http:\\justkdx.dirtrider.net

(no www!!!)

And click on 'tech tips' and 'understanding jet needles'.

CDave has put together graphics/text and charts that tell you everything you'll ever need to know about jet needles. It's a great convergence of jetting info!!

The '73' in a R1173X you can see is the straight diameter spec. Hence:

73=P= 2.735mm
74=Q= 2.745mm

So...the '73' is richer in the straight diameter section, which as you can tell from the circuit chart is most effective to the 1/8-1/4 throttle position.

Angle is the same (the 11 part) on the two needles. Both are 1º15", call it 1&1/4º (there being 60 minutes, or " in one º)

READ THIS, it's critical to the understanding of jet needles.

The L1, or length of straight section is NOT THE LENGTH OF THE STRAIGHT SECTION!!!!!!.

Yep..that's right!! It's the length TO the spot on the needle that is 2.515mm in diameter! This is critical because of how the angle of the taper affects that measurement. The less angle of taper, the earlier it has to start to get to the L1 spec.

Say your L1 is 39.95mm (an 'N' at the end of the number). That is the length of the so-called straight section..until the needle gets to the 'magic number' of a 2.515mm diameter. With a 'B' taper needle (1º15"), the taper has to START earlier on the needle than a 'C' taper (1º34") needle does!

THAT 'taper start' is important in getting the middle throttle jetting correct.

You left off the last letter. This is important, or course. I ordered two R1173K needles from the local kawi dealer. Got one 'K', and one 'L' !!

It helps to know what your starting with before trying to figure out where you'll end up! ;)

re: 'run it on the same clip'. As good a place to start as another.

Adjust the AS to best throttle response..say off idle in 2nd gear with a load.

You KNEW this was going to be fun, didn't you? ;)