float height

[Omarttentmaker]

Having a little trouble recently starting the panhead cold. Seems to be starving for fuel. Thinking about raising the float to 3/16" from the top of the bowl like it says in the Victory book. Also noticed that in one of the drawings in the Victory book there is mention of a gasket between the venturi and the nozzle, but the manual doesn't show a gasket. Is that gasket for a particular model Linkert, but not the M74B? BTW, have checked for manifold leakage, seems tight. Plugs are a nice tan/brown color, carb response is excellent: no black smoke in the exhaust, no sag or miss off-idle. I use non-ethanol gas exclusively.

[duffeycycles]

look at the spark & forget the 3/16" BS

[T. Cotten]

Having a little trouble recently starting the panhead cold. Seems to be starving for fuel. Thinking about raising the float to 3/16" from the top of the bowl like it says in the Victory book. Also noticed that in one of the drawings in the Victory book there is mention of a gasket between the venturi and the nozzle, but the manual doesn't show a gasket. Is that gasket for a particular model Linkert, but not the M74B? BTW, have checked for manifold leakage, seems tight. Plugs are a nice tan/brown color, carb response is excellent: no black smoke in the exhaust, no sag or miss off-idle. I use non-ethanol gas exclusively.

So something changed, Omar?..

(Sorry I gotta ask to be sure, but you bubble-tested at a full fifteen from a regulated supply, right?)

Float setting needs to be only ruler-accurate, as long as the float floats, but arbitrary changes could be a tail-chase.

Although Palmer also alluded to a nozzle gasket for BTs, I only remember them on some military models (although I cut thin PEEK seals for all models to remedy venturi wear.)

....Cotten
PS: Plugs don't "read" like they used to.

[Omarttentmaker]

So something changed, Omar?..

(Sorry I gotta ask to be sure, but you bubble-tested at a full fifteen from a regulated supply, right?)

Float setting needs to be only ruler-accurate, as long as the float floats, but arbitrary changes could be a tail-chase.

Although Palmer also alluded to a nozzle gasket for BTs, I only remember them on some military models (although I cut thin PEEK seals for all models to remedy venturi wear.)

....Cotten
PS: Plugs don't "read" like they used to.

No changes.... actually 10psi with both intake valves closed....and I tested the rubber bands for swell or deterioration by immersing them in a jar of non-ethanol for a week before installing them.....Yes, plugs don't read like the used to, but I was hinting at that they're not white (too lean ), or black (too rich )

[T. Cotten]

No changes.... actually 10psi with both intake valves closed....and I tested the rubber bands for swell or deterioration by immersing them in a jar of non-ethanol for a week before installing them.....Yes, plugs don't read like the used to, but I was hinting at that they're not white (too lean ), or black (too rich )

Bands on a Pan, Omar?

Surely you meant O-rings?

Probably viton we hope;
I gave up on soak-testing when it became obvious that it really only tested the fuel, from only one source, blended for that region and season, and you never knew what would come out of the next pump, or if you mixed them.

I excelled at junk science.

...Cotten

[Omarttentmaker]

Bands on a Pan, Omar?

Surely you meant O-rings?

Probably viton we hope;
I gave up on soak-testing when it became obvious that it really only tested the fuel, from only one source, blended for that region and season, and you never knew what would come out of the next pump, or if you mixed them.

I excelled at junk science.

...Cotten

Yes, I meant o-rings. And I get my gas in the same region all the time....It's not like I'm gonna go to Florida on my pan tomorrow, even if I they were givin' away hundred dollar bills! Anyhow, my guess is one fuel refiner makes all the non-ethanol and sells it to different fuel companies. That's how mega businesses work....and there ain't none bigger than the oil business!!!!! None of 'em wanted to make non-ethanol to begin with, but when they huddled and found out they'd be able to gouge us on the price, away they went!

[T. Cotten]

No doubt ethanol makes fuels worse, Omar,..

But even non-ethanol fuels will have Federally-mandated additives that are hard on rubbers and stuff. (In the name of clean air, etc.)

One kind in particular are "Intake Valve Deposit" inhibitors, which I suspect are also why plugs burn clean and white, even when mixture is ideal.

So now she's hard to start cold, but she started out easy?

....Cotten

[Omarttentmaker]

No doubt ethanol makes fuels worse, Omar,..

But even non-ethanol fuels will have Federally-mandated additives that are hard on rubbers and stuff. (In the name of clean air, etc.)

One kind in particular are "Intake Valve Deposit" inhibitors, which I suspect are also why plugs burn clean and white, even when mixture is ideal.

So now she's hard to start cold, but she started out easy?

....Cotten

Yes, it did when I rebuilt the top end 4 years ago. I'm into teardown now. Will look at the o-rings. Wanna make sure the venturi is snug. The journey continues.

[Omarttentmaker]

Yes, it did when I rebuilt the top end 4 years ago. I'm into teardown now. Will look at the o-rings. Wanna make sure the venturi is snug. The journey continues.

20230516_131531.jpg
Just a pic of what the plugs and the old o-rings looked like. I took the old rubber out and put a little larger sized o-ring in. The ID on the new rings is the same as the stock ones, but the material diameter is a tad bigger. Although I didn't see anything amiss with the old rings. Venturi in the carb is not a press fit, more like a light hand press. I also turned the nozzle holes so thaqt they face the throttle side of the carb.

[T. Cotten]

The only way you can see something amiss, Omar,

Is if you see bubbles.

I endorse JAMES viton O-rings, and clamps with no larger than a #10 fastener.

Its important to have a *sweet* venturi, but that has little to do with starting.

....Cotten

[Omarttentmaker]

The only way you can see something amiss, Omar,

Is if you see bubbles.

I endorse JAMES viton O-rings, and clamps with no larger than a #10 fastener.

Its important to have a *sweet* venturi, but that has little to do with starting.

....Cotten

Cool....Thanks for the input.....It's back together....Will fire up in the AM

[Omarttentmaker]

Cool....Thanks for the input.....It's back together....Will fire up in the AM

Finally got around to firing it up today....Two prime kicks, full choke....Half-choke, 3/4 throttle......BOOM! Took it for a short putt just to make sure of my carb settings. Plugs were sooty, so I fiddled with the low speed circuit. Seems I must have dialed the low speed needle out when it wouldn't start so well. Brought that back to what seems to be the best spot for this rig, about 10 clicks open from when she started to lean out. Gotta put maybe 40-50 miles on her just to verify the carb settings.....Thanks to all!

[T. Cotten]

If it runs, Omar,...

You can ignore the plugs until it doesn't.

Please count the turns on the needles so you can return, if tuning strays too far,,,

(With a "blue-printed" Harley Linkert, I sent M74series out at three-quarters of a turn on the needle-that-does-littleornuthin, and three and a half on the Idle; I firmly believe the book-spec of four-plus was because they knew the manifolds often sucked.)

Please warm the machine and tune for a high idle speed; At cruising speed, adjusting the HS needle might make a difference, and then the LS can be re-adjusted back at high idle. And then repeated, as the needles over-lap.

....Cotten

[Omarttentmaker]

If it runs, Omar,...

You can ignore the plugs until it doesn't.

Please count the turns on the needles so you can return, if tuning strays too far,,,

(With a "blue-printed" Harley Linkert, I sent M74series out at three-quarters of a turn on the needle-that-does-littleornuthin, and three and a half on the Idle; I firmly believe the book-spec of four-plus was because they knew the manifolds often sucked.)

Please warm the machine and tune for a high idle speed; At cruising speed, adjusting the HS needle might make a difference, and then the LS can be re-adjusted back at high idle. And then repeated, as the needles over-lap.

....Cotten

just for the record, what do you like for the RPM of a "high Idle"? My benchmark is to increase RPM at the point where the generator light is not flickering or goes out when the switch is in the first position (no headlight). BTW. I have never noticed a difference at cruising speed no matter where the little-or-nuthing is turned to!

[T. Cotten]

just for the record, what do you like for the RPM of a "high Idle"? My benchmark is to increase RPM at the point where the generator light is not flickering or goes out when the switch is in the first position (no headlight). BTW. I have never noticed a difference at cruising speed no matter where the little-or-nuthing is turned to!

Without a tach, we are only guessing, Omar!

But the advanced idle speed must be high enough to smooth out the motor pulse: "Potato-potato" might be sexy, but the motor doesn't like it.

The theory I have read about the late HS needle is that the fixed jet meters the majority of fuel, and the needle is used to trim down any excess at high altitudes, etc. (Hence it was dubbed the "Denver jet".) Here in the Midwest, the arbitrary three-quarters-turn worked well in that it didn't cause problems, when everything else was in order.

When road-tuning any Linkert or DLX Schebler, we must keep in mind that a rich idle needle setting leans the highspeed circuit, so if you are lucky enough to have a highspeed that responds, you will want to bounce back and forth between tuning the two, coaxing them to their sweet spots for your fuel and other variables.

...Cotten