416 jetting

[DantheEXman]

I know this has been discussed one-thousand and one times, but the search wont work when you type " *416* *jet* "

So, With a 416ex (11:1), hotcam stage 1, mild port and polish, sparks exhaust, k and n air filter with 6 1" holes drilled in air box. stock carb.

What needle position should I run? Right now it is the second groove from the top (second leanest position)

I also have a 165 main keihn jet in it and it seems to backfire slightly on the deceleration. Is this normal?

It responds quick, and does not pop on acceleration. Just a slight popping on deceleration.

My plug is a very very light tan color, beige almost.

Does a 165 keihn jet sound correct? Should I go up one more to a 168? Or keep the 165 and raise the needle one position.

It sounds too high of a jet to me, but I;m not sure, Thats why I'm checking around to see what everyone else runs.

[hondarider2006]

What do you have for a pilot jet?? If its stock, Order a 42, take out the choke, throw in the 42 and about 2 1/2-3 turns out on the mixture screw should help with the back firing. If your plug is the light tan at WFO, try the 168 and see how much that helps.

[Kilabanshee]

Try 158 main jet without messing with anything else.

[cals400ex]

i don't see any reason why your on a leaner needle clip position than stock?? what is your elevation and the temperature you ride in?

[DantheEXman]

I have the 42 pilot, choke removed.

I had the needle lean because I originally had dynojets, and it was running a tad rich in the mid throttle range with the 170 dyno jet.

So I went back to stock jets for less confusion and I still have to raise the needle up one. Will that help? Or should I go to a 168 main at the same time as raising the needle.

[DantheEXman]

And its not really a loud backfiring, its more of a popping and cracking when I let off. Is this normal for a Sparks X-6?

[DantheEXman]

Bump, any suggestions?

[hondarider2006]

It will pop and crackel some what, but it shouldn't be a loud backfire.

[HondaMan222]

mine runs awsome with 178 mikini jet, different pipes so it might be close

[cals400ex]

are you running the stock or dynojet needle right now?

[s-10s_rule]

165 is what I run with my 416 without an airbox lid at all, that is the highest I can go without it breaking up top end at w.o.t. Slight popping is normal, what causes that is the pilot jet and/or screw position. If it isn't idling too lean or stumbling off idle it should be about correct and the popping is noting to worry about, like others said, as long as it does not sound very loud, like a backfire, if it does try going out a half turn of your pilot screw and see what happens.

[cals400ex]

Originally posted by HondaMan222
mine runs awsome with 178 mikini jet, different pipes so it might be close


why are you running a mikuni jet?

[DantheEXman]

Originally posted by cals400ex
why are you running a mikuni jet?

I was wondering the same thing.

And I am running the stock needle.

So should I try a 168 main?

It does not stumble off acceleration. And it does not backfire at all when I accel. Just a little bit of popping when I let off the throttle.

So should I go up one jet size? Or adjust the pilot screw.

[cals400ex]

i would try 42 pilot, 3 turns out on fuel screw, 3rd or 4th needle clip position ( i prefered the 4th on the stock needle after i built my bike unless your at really high elevation levels), and a 165 keihin main sounds good.

[DantheEXman]

I Have the 42 pilot in. The screw it stock setting.

Should I put the dynojet needle in?

When you say 3rd or 4th clip position, do you mean from the top, or from the bottom.

[cals400ex]

i am talking about the stock keihin needle in the 3rd or 4th position from the top. i wouldn't run the dynojet needle unless your going to run their mainjets too.