do i need a needle adjustment?

[kamkamdac]

ok, when i crack my throttle and take off slowly the power gradually and evenly climbs all the way from 1.5k (where i let out the clutch) to 4k ( where i shift into second)

when i give it some gas and open the throttle a bit more the engine will be a bit boggy from 1.5k-3.2k, accelerating the same as if i had the throttle just cracked. around 3.2k the bog goes away and power jumps up.

do i need to adjust my jet needle to fix this. im thinking of going up a clip and leaning it out a bit ( i have a dinojet kit)? ive already tried different A/F screw settings with no change. carbs are clean.

[shpielers]

I'm sure Aresenic will jump in here eventually, but sounds like those carbs aren't clean yet. I believe your pilot circuit is still dirty if it is your low RPM range that's bogging down.

[kamkamdac]

these carbs are spotless, i fallowed carbs 101 to the letter. i even took a thin piece of wire and made sure all the tiny ports are clean. i can see through all three 3 holes on the pilot circuit on all 4 carbs.

[arsenic]

Sorry, I don't have a miracle answer. It's not possible to diagnose what somebody else says they did. He's "says" they're clean.

[kamkamdac]

do you think a needle adjustment would help or does the needle not have any effect at such low rpm regardless of throttle position.

maybe i just need to go up a size with my pilot jet. i know arsenic suggested that to me while i was trouble shooting a different problem.

[arsenic]

No I didn't. I just agreed with the other guy who should.

[kamkamdac]

your rite, my mistake.

so what do you think could alleviate this problem? larger pilot jets? needle adjustment? sledgehammer?

[arsenic]

A Factory Pro jet kit.

[pnkrckr0915]

when i had a dynojet kit in mine it was the same way, i fixed it by going back to the stock jets and needles, back to running like a champ. im with arsenic on this one ditch the dynojet kit.

[kamkamdac]

ive been thinking about getting a factory pro for a wile now. i never here good things about dinojet and i think its the reason for my poor gas mileage as well. ill pick one up in a few weeks and see how it goes, but i still think the sledgehammer was a good idea as well.

thanks for the help

[Kreylyn]

8K rpms + (WOT - wide open throttle) = main jets only
5-8k rpms = jet needle possition/emulsion tubes/needle jets.
3-5k rpms = float heights
1-3k rpms = pilot jet system. (pilot air jet, a/f screw settings, pilot fuel jet, and all the various passages that connect them through out the entire carb body)

But... fuel delivery isn't nessasarily the only issue you may have. Weak spark, missing spark, or arcing wires/plugs may cause a weak lower rpm power range.

vacuum leaks from faulty seating boots on the carbs/airbox, open airbox, aftermarket air filters, missing oil drain line or line not capped off, or improperly synced butterflies will also cause the issue.

Things to do...

Run the bike in low light/after dark with the gas tank off. See any sparking/arcing?

Check the plug wires are soft and bendable especially where the plug boots attatch. If not, click it back and screw the boots back on for a fresh connection.

Blip the throttle quickly in neutral and very closely note the response of the engine. Report in detail what it does back here. (I'm not gonna type out the 20 possible things it does and what it means, sorry...)

Krey

[kamkamdac]

Blip the throttle quickly in neutral and very closely note the response of the engine. Report in detail what it does back here. (I'm not gonna type out the 20 possible things it does and what it means, sorry...)

throttle response from blipping is idle rmp dependent, which is a/f screw dependent.

currently i have a/f screws set to 2.3 turns out and idle at 1.25k. quick blip at these settings will cause no dip and no hang. if i lower idle rpm then dip will appear, if i raise idle rpm exhaust sound starts to fluctuate in an annoying wa wa sound, blipping the throttle will cause slight hang. raising the idle higher (say 2k), wa wa gos away but there will be saver hang and and cause idle to jump to 3.5k. (no stable idle rmp between 2k and 3.5k).

these results change if i adjust the a/f screws. at 2.5 turns out 1.4 has best idle with no hang or dip. after hearing everyone comments i think the pilot jet is the problem, it seems it gets leaner as rpm increases


checked wires and plugs, everything looks good. voltage is above 10.5 at the coils, dont know exact number because i have a crappy 5 dollar volt meter. temp coil mod made no change. carbs are synced, re-synced and for good measure re-re-synced.

[Kreylyn]

I would go back to looking at the pilot system then.

All these tubes internally need to be as clean as the jets...



Krey

[XXWoodmanXX]

I concur. To be honest I never even knew that blue passage existed until Krey posted this image. Helped me fix my idle issue. Thx!

[kamkamdac]

thank you for the diagram but i have meticulously cleaned out the carbs several times since that's what everyone keeps suggesting to me. i have torn them down, soaked them for 24hr in cem b-12, and cleaned out all passages with a wire 3 times in the last month. spray floes from main jet port to pilot jet port, and the same for pilot jet to transition port freely.

i think the pilot jet is the problem but if anyone thinks the problem could be caused by anything else other than a dirty carb ied like to here it. im far from an expert but i think ive ruled out dirty carb.