Bing Fine Tuning / Idle to Mid-range Transition

[Mike V]

I wanted to report back as I promised with some comments on a successful ending.  Come to find out - this was not a jetting problem after all.  Even though I was suspicious about this being a blockage due to the red lead primer from the tank, I just wasn't sure.  But the bike continued to worsen and I had enough of the coughing, sputtering and stumbling.  I pulled the right carb first and closely inspected it.  It was pretty clean from the past rebuild only a few months ago except for the bottom of the bowl and the metering needle.  There was still fine primer material in the bottom of the bowl after several cleanings although lighter from the previous inspections.  The needle had a residue build-up on it I've never experienced.  And a residue ring up high on the needle I had to remove with force with a thumbnail.  These were new needles.  This residue ring was high in the area of the atomizer.  I don't know if I found a bad tank full of fuel or what.  I also found a minor tear in the idle jet o-ring.  Long story short; I completely disassembled the carbs, carefully cleaned all the jet orifices, flushed with carb cleaner then compressed air...AGAIN.  New o-rings and gaskets.  And mainly --- a paper in-line filter.  The bike runs fantastic, crisp and responsive through all the ranges.   What a joy this bike is.  Especially now that I'm able to throw my $100,000 leg over it and enjoy it.

Thanks for all the tips, opinions and help guys.  

-Mike V. / San Diego

I have an extra pair of 2.66 needle jets if anyone needs them. (duh).

[montmil]

[smiley=clap.gif] Mike!

Good on you, buddy. With these Airheads, it's usually something simple; we just have to find it.

Primer? As is paint primer? That ought to be a first for carb concerns.

Anyways, take care of that expensive knee. No "throwing" just yet... [smiley=thumbsup.gif]

Monte

[Mike V]

Monte,

This "primer" is the red lead primer from the inside of the gas tank.  This bike sat for over 15 years with a very low fuel level in the tank before I restored it.  I flushed the tank with soap and water several times before the first start-up and even though it looks quite nice inside in regards to coating I flushed a lot of material out of it.  No rust in the lower seams I could see.  I think my first mistake was not having an in-line filter at the time of break-in, then my second mistake was installing one of the small bullet sintered in-line filters.  This filter didn't seem to catch the debris.  I've since installed the paper filament in-line filter in hopes of doing a better job with this very small "stuff" that I found in the bottom of the bowls.  Thanks for reminding me of the 'KISS" principle!  Emphasis on the last "S" of the acronym.

And a shout-out to Bill, Mike and Barry --- I was wrong about the 2.64 needle jets being in the carbs, stock jets are 2.66 as you all mention.  Even had it recorded correctly in my notes, I guess I should have referred to them.  They were 2.66's all along.  Remember that "S" mentioned above?

She's firing in concert now!

-Mike V.

[Bob_Roller]

Looks like you may want to consider relining the interior of the tank, when you get some extended rainy weather next spring in southern California .

[Mike V]

You're right Bob, but a job I'm trying to dance around as long as possible.  Those 3 flushes may not have been enough.  The debris from the tank has lessened but it's obviously exposing bare metal somewhere.

-Mike V.

[Vegasrandall]

I did a volvo tank with the stuff called kreme and had good results.Ispent a lot of time tumbling the tank by hand with sandblasting grit inside to clean it.