Proper Tuning... how to?

[fillibuster]

Cotton!!!

Yup... the "Armored School Handbook" even teaches the riding of the motorcycle!!! It's a great book. The "new" factor is a good point. That's why I ask questions in addition to doing the reading. You can't beat "good" modern day answers for our "old" bikes. If not a book... then maybe a booklet???? I'd buy one.

Interesting compilation of "initial" settings Harry. Again.... I'd go with Cotten's recommended settings. Once the machine is dialed in... make sure you resist the urge to fiddle with it if the bike starts acting up. In my experience it usually means electrical problems... I've been guilty of cranking on those needles trying to fix the mysteries of electricity!!! It was all frustrating but I learned sumthin'!

I have to agree, Cory. I've fiddled with the carb while it was the points/coil/condensor b.s. that needed attention. MOST TIMES "it's never the carburetor", but the spark. ...
That said, peculiarly, I have managed to get different behavior out of my engines with carb adjustment (though carb never cured bad spark), choking the hell out of it thinking it was starving for gas, for instance, and eventually fixing the points for the real cure. Oddly, it seems weak spark can find some compensation in a rich mixture (?????????) ........ am I full of beans here? somebody kick me!

[T. Cotten]

Filibuster!

I am not even allowed to kick my seventy-pound "puppy", although I admit I kept him from running into traffic that way, once.

But I agree with Cory as well: All other things must be in order.

Ordinarily, the culprit is a vacuum leak, but hopefully Harry has that covered.
It is possible however, to have leaks elsewhere, such as a sparkplug, compromised headgasket (the "low spot" of a Chief cylinder deck is always over the intake port), or a diabolical casting porosity (Milwaukee machines are far more prone to those).
One vacuum leak interface that cannot be addressed by bubble-testing is the manifold-to-carb junction. But the only reasonable test suggested has been an un-it propane torch while the motor is running at different RPMs, and temperatures. I arbitrarily re-cut all manifold flanges, (and they all need it)

I've a late-model buddy who uses a CO2 fire extinguisher.
He can almost tell me which side of the bike its on.

....Cotten

[fillibuster]

Filibuster!

I am not even allowed to kick my seventy-pound "puppy", although I admit I kept him from running into traffic that way, once.

But I agree with Cory as well: All other things must be in order.

Ordinarily, the culprit is a vacuum leak, but hopefully Harry has that covered.
It is possible however, to have leaks elsewhere, such as a sparkplug, compromised headgasket (the "low spot" of a Chief cylinder deck is always over the intake port), or a diabolical casting porosity (Milwaukee machines are far more prone to those).
One vacuum leak interface that cannot be addressed by bubble-testing is the manifold-to-carb junction. But the only reasonable test suggested has been an un-it propane torch while the motor is running at different RPMs, and temperatures. I arbitrarily re-cut all manifold flanges, (and they all need it)

I've a late-model buddy who uses a CO2 fire extinguisher.
He can almost tell me which side of the bike its on.

....Cotten

What I really was, was trying to ask, is whether a rich mixture can compensate for weak spark, not sufficiently for normal operations, but enough to keep one guessing (wrongly) that the carb is out of adjustment. I'm saying I think so, from my own experience. Not that I'm addressing Harry's problems in this question either, please. The question is for the sake of discussion, because (as pointed out) many of us have overlooked spark as a primary culprit, and have twisted their carbs all out of adjustment meantime.
I have a 9n Ford tractor also, and its coil is about finished with its 12-volt endurance testing. When it fails, I can still let things cool for just a few minutes, then start it with heavy choke, and it can run with heavy choke back to the shed. My Chief has behaved the same way before too, when points and battery and coil were in question.
Harry has asked us to discuss things of this nature, not strictly carburetor.

While I'm at it (Harry), for my thinking, a lean mixture sounds too crisp, and causes "coughing" or backfiring, like you get when you run out of gas, or when you crack the throttle during warm-up. A far-too-rich mixture fouls the plugs alternately or intermittently, causing rough running at idle and light load, and cause heavy smoking, and does not sound crisp at all. That is basic stuff explained in the manuals (I think that's where I got it)
Some people adjust their high-speed needle (power) at max throttle, where it runs the most power. I think that's too lean for moderate demand.

Hadn't seen comments on that, so thought I'd offer, for better or worse. ..... is that worth 2 cents?

[phillie]

Harry you lose my number?? haha

[pisten-bully]

..... is that worth 2 cents?

Absolutely worth the 2¢ Phil! I like your notes about exhaust "tone" especially as particularly this time of year, when it's 70 degrees one day and barely 50 the next and I fiddle with the needles I've been using the tone as one of the clues. This is all good stuff to me, it helps me think I'm on the right track (even when I may not be!)

And, again, the whole picture of tuning… so that I don't automatically blame the carburetor every time, is where I want to be heading. Carburetion, timing, spark, and other factors all relating to how the engine is behaving at the moment… and maybe Cory's idea of the Fort Knox book would be a good read (if it's not I can always use it as a sleeping pill on "on of those nights").

Please note that a rich lowspeed setting becomes a lean one when the venturi kicks in!

I like that too, Cotten, but I'm not certain I understand it fully!

[fillibuster]

Ahhh… Cotten! I think that's exactly the sort of advice that needs to be put into a single resource… why don't you write a book… I'll purchase one! (surely that old Windows machine you've got has MS Word on it!)

Well.. I did leak test the manifold when first installed with the those new state-of-the-art seals you set me up with… couldn't make any bubbles and I've snugged up the manifold nuts twice since then. The carburetor was re-built in 2012 (long story… I purchased a carburetor kit from Greer's, then I remembered the Marvel/Schebler carburetor that I rebuilt for my Ford 9N… and I chickened out and sent the kit back along with the carburetor for Greer's to install so that it wouldn't turn out like the 9N carburetor episode a few years back… enough about that!)

I'm just looking for some reading… something that tells me for example, "if your Linkert equipped flathead hesitates, it could be caused by this or that so you should check these things….."

Make sense? Anything out there like that?

Tractor-distractor here!
I have 9n and 841 Ford tractors, have done the carb on the 9n, may do the 841 too, but it's probably in the ignition. HOWEVER, I found an interesting method on tuning the carb for power. The IT manual says, after warm-up and idle adjustments and a few minutes of sitting still at various throttle exercises, bring to full throttle and remove plug wires 2,3, and 4, and adjust power screw for fastest rpm on 1 cylinder! .... then re-attach wires, check idle adjustment again, then 1-cyl only again, then re-attach, and you are finished.

The method makes sense, though. Dad used to "walk" alongside the tractor while I pulled a plow, adjusting, and I was nervous as hell about running him over. One cylinder pulling 3 dead ones would apply enough load to get the mix right for all.

Been thinking, I've always set the Chief for full power on the highway, but at 130 I can't hear anything but the wind!
'spose one cyl would slow me down to, say, 90?