Carb rebuild new cables....

[weasel01]

Thanks Justin I will try that.

The only thing I noticed inside the carbs that caught my eye was one of the needles had a small nick in the side of it the other was shiney and new looking?

Could this be contributing to my issue?

[Justin B.]

I suppose that any damage to the "needle" part of the screw could cause difficulties of some kind.  Another thing, if the idle mixture doesn't help, might be to raise the slide needles a notch.  I have had a clogged up "intermediate jet" but this caused a whole lot more than a brief flat spot.  But, you might want to make sure all of the little bitty holes in the intermediate jets are clear and also that the O-ring on the jet didn't get sliced when putting it back together...

[montmil]

Big box stores like Lowes, Home Depot, Menards or even Ace Hardware carry little plastic tubs of "Plumber's Grease". It looks and feels like our favorite dielectric grease but I dunno what it's composed of.

Anyway, this stuff -applied in very small portions- goes a  long way in preventing tearing, galling, rolling, etc of rubber O-rings and other similar bits.

I used the stuff during the Bing overhaul adventures with Blackie to insure a no-damage reassembly.

[Justin B.]

I just use silicone grease.  I hate anything even remotely related to plumbing...  [smiley=puke2.gif]

[weasel01]

I'm pretty sure it's an adjustment issue as the carbs are much touchier than before (probably because they are working correctly now)

I'm gonna try the richer setting Justin suggested.

[montmil]

I just use silicone grease.  I hate anything even remotely related to plumbing...  [smiley=puke2.gif]

Gotta be a really good story in there somewhere  

[weasel01]

I fiddled with the mix screw a bit and improved the just off idle response
but at the cost of the super smooth engine sound.

Did a bit of research and found several references to the transition from idle to "go" rpm increase was more affected by cable balance?

I'll try that next..

Read a cool debate on another forum about the sync method of just off idle (say 1300 to1500rpm) vs. 3k to 4k rpm method?

Snow bum says above 1500 is a waste of time (with bing cv)as the adjustment is less dramatic than just above idle ....logarithmic response is guess...

thoughts?

[montmil]

Although I did not need to change out throttle cables during the overhaul of my 32mm's, I did work quite diligently getting the cables just so.

I found that the amount of slack in each cable must be perfectly equal or the engine may stumble just off idle as you pull away from a stop. Sound familiar?

Note that the air mixture screw position on the Bing makes a rather large difference in carb operation. Very small position changes create even larger operational changes. There's usually no more than one-eight of a turn between the stock 3/4 out and an ideal run position. They are touchy little rascals.

Also, just moving off idle, the Bing's fuel metering begins transferring to the needle and needle jet system. Your nicked needle could be hanging up in the needle jet but not likely if you smoothed it off. The main jets begin to meter fuel from perhaps 80% throttle up to WFO.

Revisit your cable adjustments; primarily at the length adjust screw on top of the carbs. Bet that's where you'll lose the off idle weirdness.

 [smiley=2cents.gif] Monte

[weasel01]

Ok ...got it lined out.

Went for a nice long ride on my way home today pulled up to my garage  I prepped the fan manometer and tools this morning so it was all ready to go.

I think I'm getting some "new cables settling in" phenomenon.

Went back thru the whole proceedure and it feels great again!

We will see tomorrow but it felt right tonight.

[montmil]

...could be those new chickens messin' with your ride.

[weasel01]

...could be those new chickens messin' with your ride.

I tell ya' what if I catchem' ...it's straight to the fryin' pan!!!

[bjamesw]

drgnfli,

I've often thought that eventually when my bings need major service, I'd swap in Mikunis for the sake of newer engineering,  cheaper more available parts, and less worry about that diaphram.  

Do you want to switch back for the sake of maintaining originality?  How did the Mikunis perform?

[weasel01]

Dang it ...it might be those chickens after all...

I had it dialed in perfetly last night ...went for a long cool down ride and it wass silky smooth.

This morning it was super hard to start and my hesitation off idle is back?

This has proven to be the hardest step to get right so far....

[montmil]

Hard to start and off-idle hesitation may be two different chickens.

The Bing float bowls have a separate fuel reservoir for the enrichment system... hereafter known as the choke.

There is a tiny brass plug in the bottom of the choke reservoir that connects with the main bowl. It must be clear so that fuel can move between the two chambers and remain at the same levels. There is a small brass tube from the carb body that extends into the choke's fuel chamber.

Sometimes fuel deposits clog this tiny orifice which leads to hard starting. Usually, it's just one cylinder that's not hitting until the engine warms up a bit.

Perhaps return to "square one" with the idle jet screw at 3/4 out. See if starting is easier.

I would get discouraged and mildly p*##ed at my Bings but if you can stand the strain, you'll get it sorta out. Have you confirmed that the diaphragms are properly seated with the little rubber tab in its tab hole?

Monte

[weasel01]

Yes diaphrams are properly positioned...I just cleaned the sh!t out of both carbs but you know ....now that you mentioned it this morning I did notice (when it finally started) the right cylinder fired before the left?