needle position question

[quikvrsixx]

the usual. bike has exhaust and pods to start. installed stage 3 jet kit with the larger jets. bike ran good but super rich with the recommended setting on the 4th notch down for the needles and the mixture screws at 2.5 turns out. changed the needles to the 3rd notch down and it seems like it did not make a change at all. is it normal to have to move the needles again up one more notch and should i change to mixture screws less than 2.5 turns out? thanks in advance.

[crazypaint]

i had to change my main to the lower one wanna say it was like a 132 but cant remember the jet number i think the other one is a 138 that being the larger one

[OldVet66]

Mine is running VM carbs, on the third notch, which could be too lean for most bikes according to the gurus on the site here. If I remember correctly, that puts the clip in the middle of the DJ needle notches. Recommended settings are to start on the fourth notch from the top of the needle. The fourth notch setting is with the DJ 138's, having to go up to the DJ, 142 jets in some cases, but that is the exception. For your type of carb, I would get more detailed information from those that know, and keep a constant check on the plug colors until you know what is going on inside your motor for sure, doing plug chops. If you have the 142 jets installed, change to the 138's and the fourth clip position first. Mine was running too rich on the fourth clip, causing a stutter and plug fouling in the mid range RPM's. Dropping the needle one notch by raising the clip, cured that and the plugs are a nice chocolate brown color now instead of a sooty black.

[trippivot]

the mixture screws NEVER have a common setting on all 4 cylinders. many people do it but they are not fine tuning anything. 2 or 2.5 is a starting point to get it running on it's own

each cylinder has it's own stoich. requirement. so idle drop each cylinder 1 at a time to get the highest idle - re set the idle speed and move on the the next cylinder.

tuning carbs starts with idle then needle finally main
because ALL the fuel circuits all add up together and flow when you are close to or at W.O.T.

[Turtleface]

the mixture screws NEVER have a common setting on all 4 cylinders. many people do it but they are not fine tuning anything. 2 or 2.5 is a starting point to get it running on it's own

each cylinder has it's own stoich. requirement. so idle drop each cylinder 1 at a time to get the highest idle - re set the idle speed and move on the the next cylinder.

tuning carbs starts with idle then needle finally main
because ALL the fuel circuits all add up together and flow when you are close to or at W.O.T.

Not only do the mixture screws have different requirements, but every single engine will have different jetting requirements as well. Things such as humidity, altitude, ambient temperate, and intended motorcycle use all effect jetting requirements. That's not even getting into engine mods.

Hence the importance of doing plug chops to determine the stoich ratio for each carb circuit on each cylinder. I believe the saying is, "To measure is to know."

[quikvrsixx]

thanks for the advice. i was not familiar with the plug chop but have now read about it. any other advice is much appreciated. i wll keep up on the post to let you know where i end up.

[quikvrsixx]

i went back to look at the mains and the ones in my kit are 130's which was if you had modified exhaust or in my case stock with no mufflers. the others in the kits are 124's. i would think with the pods and less back pressure you would want the larger 130 mains? moving the clip up to the 3rd notch on the needle seemed to make zero difference which i thought was odd. it should have made some noticeable difference, but again this is my first bike so maybe i am wrong. i have a feeling i am going to be replacing the jets to make this better. i am assuming moving the clips up further will not damage anything even though it seems nobody is running on the first two clips.

Mine is running VM carbs, on the third notch, which could be too lean for most bikes according to the gurus on the site here. If I remember correctly, that puts the clip in the middle of the DJ needle notches. Recommended settings are to start on the fourth notch from the top of the needle. The fourth notch setting is with the DJ 138's, having to go up to the DJ, 142 jets in some cases, but that is the exception. For your type of carb, I would get more detailed information from those that know, and keep a constant check on the plug colors until you know what is going on inside your motor for sure, doing plug chops. If you have the 142 jets installed, change to the 138's and the fourth clip position first. Mine was running too rich on the fourth clip, causing a stutter and plug fouling in the mid range RPM's. Dropping the needle one notch by raising the clip, cured that and the plugs are a nice chocolate brown color now instead of a sooty black.

[OldVet66]

The stage 3 jet kit was designed for well designed aftermarket pipes and individual pods. I would baffle those pipes or find aftermarket mufflers. You will loose what little low and mid range torque you have. The only possible gain you will get is with the throttle wide opened, and that Kind of sucks driving through town and ticks off the rest of the world. Get some moderately decent back pressure and exhaust extraction will be more efficient in the low and mid range where you ride most of the time, and the carbs easier to tune. I guarantee you that my V&H 4-1 pipes sound way better when I lean on the throttle than strait pipes ever could. There is a bit of nostalgia associated with the odd fire of the Harley. They are after all a small segment of the radial aircraft engines they evolved from. A 1,200 hp radial exhaust is pure sex to listen to no matter how loud, but you don't see many of them riding through town.

[SqDancerLynn1]

Did you use the K&N pods or cheap foam ones?? That makes a difference