Off Idle Bog, Pilots or ? Help for the weekend!

[90Bansheedude]

Ive got stock carbs and an off idle bog, stutter, stumble, whatever you want to call it.  It starts easy, idles well and runs strong, except for the off idle bog which is interfering with my low speed vertical wheelies that i like to do, especially having a +6 swingarm on with the low speed off idle bog makes it very difficult.

 

I have tried double checking float and fuel level height, changed the needle clip many different times, synced the carbs with the tool, tried running with choke half on, no matter what, i cannot get rid of it.  What do you guys think, I was thinking it seemed like a rich bog, but doing some more reading, maybe its lean?? although the choke isn't helping.  Do you think i should go to 32.5 pilots or what?

 

Needle - has 6 clip slots, tried all but the top and bottom ones with not much difference

Ported (but not sure who or for what)

Reeds - Believe they are aftermarket but they came with it

Exhaust - Bills Pipes

Timing - Believe it is approx 4 deg advance

Air - K&N seperate direct mount pods

Carbs - stock with 30 pilots and currently 340 mains

Plugs - B8ES

Stator and Coil - Believe it is stock

Location - Nebraska

Temp - 80F approx

Elevation 1700

Engine was leak tested when i put it together, and passed wonderfully

 

Plug Chop Post Link

http://bansheehq.com/forums/index.php?/topic/182681-340-jets-plug-chop-and-plug-read-opinion/

 

I am trying to get it all done and tuned perfect for a possible trip this weekend, but if i need different pilots i will have to see how fast someone can get me some.

 

Brian

[fastbanshee8]

How many turns open are your air mixture screws?

[90Bansheedude]

currently 1.5 out, but tried from 1 to 2

[Surfrjag]

Check your pickup gap and open the air screw to 3 turns and see if that helps. Stock reeds?

[camp0429]

I' ve got a very similiar set up as you, except Pro Circuit's, VF3, and I'm at about 450 asl, when I switched to pods, I went up to a 350 main, 6 groove needle also, (don't know brand) was at second groove from bottom. I also had a noticeable bog off idle, went to a 32.5 pilot and couldn't really tell a difference even when I adjusted air screws, set needle up one groove and it was way better but still stumbled a little, went another groove up and cleaned it up. Just going up 2 grooves on needle made a huge difference.

[camp0429]

Check your pickup gap and open the air screw to 3 turns and see if that helps. Stock reeds?

 

When I was having the same issue, I checked/set pickup gap as well, also replaced plug boots (their cheap enough not too) and plugs, trimmed coil wires back some.

[90Bansheedude]

It has new plug boots on it already also.

 

@ Camp, so you ended up with 350s and 32.5s to richen the pilot and then leaned out the needle 2 grooves?  Was that the final fix or did you do the pickup gap at the same time?

 

I think i would have checked the pickup gap when i put it together, but it was awhile ago and i cant remember.

 

Its scary to think that the guy before was only running 280 mains!!  No wonder he melted a piston.

 

I will see if i can find some 32.5 pilots that can get shipped to me before the weekend and try those.

[camp0429]

I set the pickup anytime I have the cover off, but in the end it was leaning the needles that helped since I went up on the mains when I wen to pods

[Lowroll]

Rocky mountain has pretty fast shipping, standard 3 day and for a little more you can get 2 day. I would get one size pilot larger than what you think you need also. I bought jets one size each way of what I expected to run so I could tweak. I too have a very similar off idle bog that I have not yet found but my setup is much different. I went 3/4 turn in on my air screws and cleaned it up a bit but much like you, I have enough bog to kill its wheelie torque. Im going to play with needles tonight

[90Bansheedude]

Well i tried it a couple times after work today and when it was cold, it seemed better, and when i leaned the needle out completely and turned air screws out 3 turns, it seemed better, but not 100% yet.  Im going to borrow some 27.5 jets from 99michael probably and try them to see, and i may also try some 320 mains i have just to verify if it is lean or rich.  If those dont help, i will go back to 340s and may try drilling out the pilots if i can figure out approx how large they need to be comparing the 25s, 27.5s and 30s that i have available as a test.  If i need larger pilots instead, i probably wont get them by the weekend, but its not a deal breaker, just would have been nice.  I called all of my local sources today, and no luck with any jets or getting them from them soon enough.

 

I also have some T5 pipes that i can try from 99michael if i want to.

 

The one local parts guy said if its ported massively and modded greatly i may be out of luck, but im not taking that as an answer.

 

Will keep you posted.

[90Bansheedude]

I think the 27.5s were too small, seemed to heat up fairly fast at idle and still didn't fix what i was trying to fix so i put the 30s back in.  I did put the 320s in and it might be slightly better, still doesn't run hot, likes to stay around 180ish give or take, but maybe im just expecting too much stabbing the throttle at too low of rpms.  Im getting tired of messing with it.  If i feel like it tomorrow, i might try swapping the pipes and see what that does.

 

For now, i will work on wiring up my Trail Tech Rec/Reg for the lights.

[sleeper06]

After you ride the bike and get it up to temp does it idle real low at a complete stop . Every motor is diffrent I don't concern myself with what everyone else runs . Once an engine is ported reed selection, needle diameter,pilot selection play a huge role. I just jetted a ported bike and ended up with a 35 pilot on a mild port . Have u tried putting stick needles back in it . Something that sticks out to me is no needle adjustment helps so that leads me to beleive wrong needle for your motor . I'll look at your plug chop pic now

[sleeper06]

That 340 plug chop looks great . Leave the main and move on to needle and pilot selection. Do u have a sync tool curious on how many Cfm its flowing at idle? By you saying your idle screws are barely in tells me your pilot is too small the bigger your pilots go the more you'll have to lift the slides with the idle screw. I like too keep feeding it pilot till it doesn't like it you might be suprised what you end up with. It's not a quick process but worth it in lugging power and oof idle response in the end

[90Bansheedude]

I dont have the stock needles, only whats in it.  If i need other needles, pilots or reeds, i will have to order them.  Yes, i have the sync tool and it reads about 5 at idle and i was setting part throttle at about 13.  Maybe im not going about diagnosing the problem right.  I do know that with the 340s in, and the needle close to the middle riding trails it was getting loaded up, so If i have the 340s in i should lean the needle.  I think with the 320s in and needle close to middle that problem is gone, although im not riding trails, but on the road and in my yard (3 town lots) which is a little different.  The gurgle i was trying to get rid of is when rolling really slow in first and punching it WOT it gurggles and then takes off, but past the point of bringing up low speed wheelies.  But after watching abunch of other banshees, i notice almost everyone clutches to wheelie, with the Blaster i used to have with a +4 swingarm and the Raptor 660 stock swingarm, i never had to clutch, just roll slow and punch the throttle while pulling back and it was up.  But thats probably because of the large pistons and low speed torque, and the Banshee has a +6 currently.  I think i am going to drop to a +2 and see how i like it.

 

How would YOU go about finding the right needle position, ride abunch of 1/4-1/2 throttle (although 1/2 ends up being pretty fast) and adjust it just until loading up is gone?  How about the pilots, put in as large as possible and richen the air screws until it wont idle good anymore and then lean/open the air screws a little or go done a jet?  Is it hard to tell if its the needle or pilot on the part throttle just off idle?  It seems like it may be to me, unless i need my pilot alot richer and my needle leaned out all the way.

 

Now if i am punching it full throttle from barely rolling, would a rich gurggle be from the full throttle main, or the pilot?  If the throttle is pinned while gurggling it wouldn't be the pilot anymore would it?  Unless its not wound enough to pull the fuel from the main yet, or has a tiny amount of already pilot metered fuel it has to burn....????

 

My jetting knowledge is enough to get them running decent, but the fine tuning I haven't done enough of to have it nailed down yet.

[90Bansheedude]

That would be 5 Kg/H not Cfm, sorry.