Raising and lowering Jet needle

[Guest]

BS34SS on a stock 81gs400l.

I tried dropping the needle one clip position because it felt rich, and rough and as if I had to force it into the upper RPM band.

I've noticed that it will rev with more ease and the upper RPM band is smoother and requires less throttle to get to that point.

I'm in Center clip position now and was one position down.



My question is for those who have played with the needle positions.

What were the results when going leaner or richer?

I haven't had the weather to test but I plan to asap, I'm just looking for insight beforehand.


Thanks.

[tkent02]

Not specific to your 400, but:
The needles work mostly between about 1/8 - 1/4 and 2/3 throttle... Wide open is controlled almost completely by the main jets, the needles don't do much. Less than 1/4 throttle is controlled by the pilot circuit.

All of these are interrelated somewhat, and all dependent on the jets you are running, both the mains and the pilots.

And of course, is the intake, engine and exhaust stock, or modified, are the jets correct for what you have?

What do the plugs look like when proper plug chops are done?

[Guest]

All stock, except slippon silencers,

Wot is good, tan-slightly rich. (going by point of arc on the electrode and the color at the back of the ceramic recess)

Haven't had the weather to try the rest of the range.

I started out working from the main jet down.

Next in line was the needle and I only had time to drop it one position before it started raining and didn't get a plug reading.

But It would have been the 3/4 throttle that I was going to do, then half, quarter and eighth,