bike bogging from 1/8 to 1/4 throttle (too rich )

[fsrdh]

Im still fighting with my carbs here is the situation

40 pilots / 122.5 mains ( cobra f1 + uni )
Floats : ok
got the float assmbl. replaced
the bike runs fine idle and high throttle openings
new gaskets no vaccum leaks
air screw 2.5 out  ( perfect for my idle)


but when I get the throttle from 1/8 to 1/4 the
engine starts boogin with black smoke form exhaust
after that everything is cool it pulls strong again .
I was able to "fix" it by taking the washer from the Jet Needle and
moving the clip to the highest position to lean it out .but now I can hear
the jet needle bottoming out on the Main jets . And it still isnt running
in that part as it should .( ofcourse raising the clip made it weaker on
higher openings too )
The jet needle looks a little worn out . So my next step is getting a new
jet Needle/Needle jet set. question is should I get it with the factory
OD or get a higher one to lean it out more ?? what OD is stock what is recomended ?And where can I buy it cheap?

PS. the bike never really run good since I bought it  as the prev owner
didnt know how to fix it so I really dont know if the needles are correct size . Its just a slow proccess of replacements and troubleshooting.
but when I got it it wasnt running at all so this is wey better

[The Buddha]

Jet needle bottoming out??? Never heard that, I'm pretty sure its somehting else though. Now adjustable needles mean you have a jet kit in it. For a slip on and UNI you are supposed to have 118's in it as per dynojet. Why 122.5's. Float too high might be the problem though. even 1 mm too high in 1 carb will do this possibly.
Cool.
Srinath.

[fsrdh]

But the main jet doesnt do anything on the 1/8->1/4 openings
I could run without it probably and get the same poor results in
my throttle range
I will try to toggle the Floats again but they will bend just a little
more as I lowered them before .
And ofcourse I chckecked if they leak and they dont
all new orings also .

Fsrdh

[The Buddha]

Well mains jet doesn't do anything in that 1/8-1/4 throttle... Actually it does... the popular misconception is that it doesn't do anything... The mains does affect it, however that range is controlled by the float level. That is a subtle difference, Meaning You can sort it out by changing the main jet, however you will screw up the main jet controlling area if you do. That's why I said DJ says you should have 118's is there a reason you have 122.5's. Now if you set the bike to run with 122.5's instead of 118's you could very well end up with a bike that runs fine mostly except for some areas of trouble. That was my suspicion. You could make the bike run fine but having 122.5's and set the air screws for idle, and lower the floats, and lower the needle to the point where it all works fine for the most part. But I suspect the bike will have some glitches (not sure where) That's why they say you should get the bike jetted top down, get the right main, then settle on the needle, then float level and then air screw. So I'd say you try to identify all the areas of trouble and see if the 122.5 mains is the right one. I'll send you DJ's instruction sheet if you want and follow that.
Cool.
Srinath.

[fsrdh]

Hey I tried the 118 and the bike run great on 1/4 but sucked on WOT
it bearly made it to 80mph.... So I think I should now try getting
my jet needles sorted out and replace the ones that I have ( cuz I dont know where they came frome    ) I suspect them to be dynojets and I heard the Dynojet are a pain in the but to setup because of the mest up taper . But then again I had no drilling  done to the Valve's
Someone told me on the groups that the adjustable jet needles are aftermarket .  I just need to know what is the correct size they put in the stock carbs and I will play with the floats again tomorrow .

[fsrdh]

Just wanted to say I got the replacement OEM needle jet from Bikebandit . So will wait and see ....

[miket]

Worn needle jets (upper parts of the emulsion tubes) will do just that: rich btw 1/8 and 1/4 throttle. More so with an aftermarket needle which is more tapered than stock. I know b/c I had the same exact problem on my other bike. Replacing the emulsion tubes fixed my problem, so try that first. Unfortunately they are not exactly cheap for a just a pair of brass tubes. You can also try using stock needles if you can find them from someone who switched to a kit. If it get better, you found your problem.

[Blueknyt]

also, some needles have different tappers to them, too sharp of a drop off on taper will screw you up too. im dealing with that now. WOT in top gear seems a touch too rich and looses power, im considering haveing a dyno run, only 25$ with gas analizer for one pass. might help me to get it dialed in.

[fsrdh]

I looked at the emulsion tube , and it looked perfectly round
not like the one one on factory pro

I took it out and inspected with a micrometer and it came fine .
Im getting the OEM needle jets and will see .

[The Buddha]

Your problem is needle. The DJ needle when I look at it makes me think it will do exactly what you are experiencing. Try stock needles.
Cool.
Srinath.

[fsrdh]

Thats what i wanted to say: NEEDLE  . needle jet/jet needle why the HELL did they name it like that  :x

I ordered a OEM replacement from bikebandit allready .

[The Buddha]

I am so sorry... I read your entire post... I had forgotten what the original post was... I think to fix the original issue you had... you should probably swap the 40 pilots for the 37.5's. But Now its a little late. Swap in the stock needle and try 125 mains. See I didn't quite read your post this time. The DJ needle will make the higher end too rich if the midrange is right, and the mid range will be too lean if the top end is right. In short the opposite of your problem. Since you had 122.5's and it caused a 1/4 to 1/8 richness I'd try stock pilots. Anyway stock needle and 125 mains will set it right.
Cool.
Srinath.

[fsrdh]

heh had 37.5 pilots : way to lean motorcycle overheating rally badly . 40 work good here. Tried 125 mains and they made the 1/4 throttle so rich
that I had to slip the clutch for way to long to feel comfortable with doing it all the time .
I think my issue is still with the floats somewhere.
next week I'm getting a K&N pod filter  / new needles / 140 /145/150 mains and will work on that from then .
The bike runs "OK" now on the 40/122.5/last (lean)eclip on needle
But I can hear the carbs rattling all the time on low openings.
and feels a little to hot in longer use . so something has to be done
with the mains too .

[The Buddha]

What you mean by carbs rattling... Never heard of that... your slides shake around so much you can hear them when riding... I doubt if that can even happen. But what else then.
Cool.
Srinath.

[fsrdh]

I'm not making this up . It sounds really cool/loud but they shake like crazy and its not any backfire , its constant from the day I lowered the needle to fix the upper lowrange/lower midrange   richnes . I will check if new needles take care of it once I get them will also check the emulsion tubes for any wear .