need carb start point VHB 30s

[Vecchio Lupo]

OK gang, I have been patiently un ham fisting the previous efforts of the last ham fisted owner, whom I shall not speak Ill of since he did lose interest and allow me the opportunity to unearth this 77 Convert from a clean-ish, dry, barn in rural SC. After loads of time and aggravation as well as money spent putting right all manner of wrongs, I went for my first ride today. She idles great, until hot then it drops too low (I can fix that) after I rebuilt the carbs I put a standard 1 3/4 turn on air screws and 2 on idles , I did not adjust the float levels (stupid) and she pulls away smooth and builds speed, but if I open up all the way, she stumbles and bogs...I can't tell if she is starving or drowning. If I back off she picks up like normal again. I have not ruled out fuel starvation, so I will check flow.

My question is what is the consensus for starting settings?? yes I will set the float height and then what?

[Scout63]

Sounds like your floats are too low.  I’dstart there and also make sure that the main jet is per the book. Do you have stock pipes?

[Antietam Classic Cycle]

Your "air screws" are actually "fuel screws" - turn out for rich, in for lean - the opposite of an air screw. I start with 2 turns out from lightly seated.

Slide height: I set a starting point by turning the screw in until a 3/16" drill bit slips under the inlet side of the slide.

[Tom H]

This is by Guzzisteve and it worked for my Ambo750:

"If you are running WFO and it comes back on by letting off a bit then the main is a tad too big. Try a few #'s smaller like 152 & see if it is a continuous accel."

Tom

[n3303j]

Those have accelerator pumps like my T3? They are functioning?

[Vecchio Lupo]

great responses, thank you, I feel like I have a good starting place. with the tighter settings, it did run better, but the same, although...rather than just the big bog. Now when cracked all the way open while moving at apt 20mph it stumbles, takes a breath, spits, and thens pulls hard until traffic makes me slow down.

Now I think I will leave well enough alone while I run some good ethanol free gas with maybe some sea foam or equivalent additive through it and give what we used to call an Italian tune up. try and blast all the built up junk and gunk out of the crevices and then see what Im working with.

[n3303j]

I'd give the accelerator pumps a good look. They should be adding a squirt when you grab a handful.

[moto-uno]

  If anyone is familiar with those 'accelerator pumps' they know that at best, they give a rather weak enrichment .
  But it is still a good practice to start with every system in the carbs in good shape and proceed to the fine tuning . Peter

[chuck peterson]

The number “145” keeps popping in to my head…

It could be my bank account tho…

Air filtration is stock or K&N?

If K&N have you included the intake velocity stacks? There is a slight venturi in those that will effect carburation

Timing is tricky…if you’ve done it statically, check it’s reaching full advance via timing light…ymmv

Good looking bike, i like the coloring. Hefty beast aren’t they? They do build speed, but slowly

In the past I would advance the timing until a few pings started showing up, then back off a touch and use a bit of octane booster, but then i tended to flog them much harder than most people here dare to. Rolling on hard at 50-60 mph in low range could surprise you

[Vecchio Lupo]

Gentlemen, and other members,

     While Im not ready to announce problem solved, I am confidant that Im on the right track. After my last post, I read everything I could find (thank you Greg Bender) and searched this and other forums, along with the good advice given here.....I did not completely disassemble the accelerator pumps when I cleaned the gummy carbs and replaced O rings and gaskets.

Fresh ethanol free fuel, little (ok a little more than a little, but not a lot) of Sea Foam, and I just ran it. She ran better and better and better. We are not there yet but after the very exacting base settings, thank you very much, minor tweaks, more than a few heat cycles, Im almost there.

the only red herring is that this whole mess was not fuel related at all, it is possible that after 5-6 dormant years, the mechanical advance was not advancing, and is only now starting to loosen up.

I can be such an idiot, just ask my ex wife. or the other ex wife.

Id rather not take apart what may straighten out with use, but unless it snaps into line this weekend, I will do just that.

thanks to all who have lent their collective brain power to helping me not be as stupid as Im capable of being. I also think I'll show up at that Virginia campout in a few months, yea haw

[Antietam Classic Cycle]

Take the cap off of the "distributor" remove the little felt pad in the center of the advance unit, and dribble some light oil into the recess where the felt pad was. Replace pad and apply some oil to it. Might help free the advance up if it's gummy.

[n3303j]

Oil the felt wick on the points cam (points grease) while in there. Better yet douse the interior with ACF-50 and it will lubricate all the pivot points in the advance unit. It will inhibit further corrosion in that area. Blow the excess off the contact points just to be neat. Then you are set for another 10K miles.

[TOMB]

If you need the wick in the top of the distributor one is easily found in the Dremel disk kit along with the disks.

Exact fit and is a much better option, just go to Wally World and look in the tool section, holds a greater amount of oil compared to the stock square wick.

Thats what i have in my Convert distributor.

TOMB

[guzzisteve]

I use exact same thing.

[Vecchio Lupo]

I almost didn't want to post so that this could fade into the back pages but...in case somebody is having similar issues and is looking for ideas and solutions....proble m solved.

Its a mystery because I don't remember completely breaking down the accelerator pumps, but I might have. well....one of them had the ball check valve mechanism installed backwards so when the engine needed fuel it got NOTHING and on over run it had wrong pressure so and so forth. Maybe I did this boneheaded thing, maybe the previous owner did, and that's why it was sitting in a garage for 5-7 years (the story varies) .

Bottom line is somebody got the assembly procedure assbjckwards but now its fixed and WoooWeeee she pulls hard from basement to attic.

Thank you and consider this issue solved.