Carb trouble

[76classic]

Ok. I'll do that and report back. Thanks so much pin_head

Ok, here's the latest. Turns out the float in the carb was way off. Also, the vacuum hooked to the power valve on the carb had constant vacuum. I guess the vacuum is supposed to drop if under acceleration allowing the power valve to open. The white canister between the vacuum block and the power. Albert was acting as a check valve of sorts and not allowing a reduction in vacuum at the over under acceleration. Problem solved. Thanks so much for everyone's input on this matter. Hope I can return the favor.

 

[76classic]

Ok, here's the latest. Turns out the float in the carb was way off. Also, the vacuum hooked to the power valve on the carb had constant vacuum. I guess the vacuum is supposed to drop if under acceleration allowing the power valve to open. The white canister between the vacuum block and the power. Albert was acting as a check valve of sorts and not allowing a reduction in vacuum at the over under acceleration. Problem solved. Thanks so much for everyone's input on this matter. Hope I can return the favor.

Here's a new Developement.
F2 runs great at start up. Drive for a while and motor quits. As soon as this happens, I shut off motor, pull over, Open hood and check sight glass. Empty. No gas. Starts up and drives for a while. Then happens again at random intervals.
The facts. New tank, new filter, new fuel pump. Carb fresh rebuild.
When it begins to stall I get intermittent popping from tail pipe.
Is float stuck in up position? Or more serious? Any help greatly appreciated.

 

[76classic]

Why not measure the fuel delivery first. Remove the coil center wire and the fuel inlet pipe at the carb. Stick the pipe into a bottle and crank the engine for 15 seconds. You should get at least a half a cup of fuel.

Here's a new Developement.
F2 runs great at start up. Drive for a while and motor quits. As soon as this happens, I shut off motor, pull over, Open hood and check sight glass. Empty. No gas. Starts up and drives for a while. Then happens again at random intervals.
The facts. New tank, new filter, new fuel pump. Carb fresh rebuild.
When it begins to stall I get intermittent popping from tail pipe.
Is float stuck in up position? Or more serious? Any help greatly appreciated.

 

[Pin_Head]

Carb trouble

 

[76classic]

Carb trouble

Thank you

 

[thebigredrocker]

Crud from old fuel line or rubber bits from new fuel line plugging carb?

Vapor lock?

 

[76classic]

Crud from old fuel line or rubber bits from new fuel line plugging carb?

Vapor lock?

I'm gonna check the screen on the intake this weekend for the crud issue.
Hadn't thought about the vapor lock thing. Hmm. Not even sure how I would diagnose that one.

 

[sggoat]

No idea if 20 Thousanths is too much. I do know from all my searching that Mark W is a cruiser guru and he uses Fel-Pro gaskets dry. He also mentions doubling with good results.

You'll find all sorts of differing opinions. I ended up choosing to try the Fel-Pro method.

Here's a link to Mark W's comments:

Double manifold gaskets?

Check out Remflex

 

[sggoat]

Carb trouble

Maybe, but if the carb bowl is empty, would seem that you may have a fuel delivery issue--how is the fuel pump doing? Do you have a glass fuel filter that you can see the fuel in? Pull the fuel hose from the carb, crank the engine and see if you get a decent fuel stream from the pump(a good pencil sized stream)if not, you may have a plugged/collapsed fuel line from the tank. If flow is good, check the piping to the carb from the pump(don't forget the inlet screen at the carb inlet)

 

[76classic]

Maybe, but if the carb bowl is empty, would seem that you may have a fuel delivery issue--how is the fuel pump doing? Do you have a glass fuel filter that you can see the fuel in? Pull the fuel hose from the carb, crank the engine and see if you get a decent fuel stream from the pump(a good pencil sized stream)if not, you may have a plugged/collapsed fuel line from the tank. If flow is good, check the piping to the carb from the pump(don't forget the inlet screen at the carb inlet)

Brand new fuel pump, tank and lines. New clear fuel filter. I'm thinking the float may be getting stuck in the closed position. Gonna check the filter in the carb just in case a piece of the old pump broke loose.

 

[Pin_Head]

The way I look at it is it isn't getting enough fuel so you have to do something about it. It might take a whole 5 minutes to disconnect the fuel line at the carb and measure the fuel output to be sure that all those new parts are working properly. If so, then the carb inlet or inlet screen may be clogged. You have to do something and you have to remove the fuel line to get in to the carb, so it makes sense to do something that is easy and informative.

 

[76classic]

The way I look at it is it isn't getting enough fuel so you have to do something about it. It might take a whole 5 minutes to disconnect the fuel line at the carb and measure the fuel output to be sure that all those new parts are working properly. If so, then the carb inlet or inlet screen may be clogged. You have to do something and you have to remove the fuel line to get in to the carb, so it makes sense to do something that is easy and informative.

I totally agree. Will check fuel flow tomorrow and share results. Thanks so much.

 

[Solace in Solitude]

Check your new fuel filter... I had a new glass fuel filter, with replacable filter element.

Every time the secondary would kick in (e.g. Going uphill, with pedal down), she would die (hardly any bucking or stumbling... Just outright die.

I could easily restart her, while still climbing, but as soon as she started, she would die again, under load.

Turned out, the new glass filter was not sealing well (e.g. Unscrew top, change filter element, screw top back on)... When the secondary kicked in, the fuel pump would suck large quantities of air in through the fuel filter's leaking seal.

Hth

 

[76classic]

Check your new fuel filter... I had a new glass fuel filter, with replacable filter element.

Every time the secondary would kick in (e.g. Going uphill, with pedal down), she would die (hardly any bucking or stumbling... Just outright die.

I could easily restart her, while still climbing, but as soon as she started, she would die again, under load.

Turned out, the new glass filter was not sealing well (e.g. Unscrew top, change filter element, screw top back on)... When the secondary kicked in, the fuel pump would suck large quantities of air in through the fuel filter's leaking seal.

Hth

Update: fuel pump pushing plenty of fuel. When I run engine at idle, fuel in glass ranges between just above and below the dot on window. When I run engine at 2000 ish rpms, fuel level runs all the way to the bottom of the glass before it begins to replenish. Is there a filter IN the stick aiding carburetor?

 

[76classic]

Stock aisin not stick aiding. SORRY iPhone correcting.

 

[Solace in Solitude]

There may be a screen filter in the fuel inlet on the carb... I would have thought it would have been cleaned during the rebuild (I think you had it rebuilt?).

When you run it at 2000ish, is it just sitting or under load?

Did you try @Pin_Head 's fuel flow test, in post# 39?

Is your filter between the tank and the pump or between the pump and the carb?

You didn't say your fuel lines are new or that you cleaned the hard lines, along the frame rail... Are you sure your filter isn't getting clogged by crap from this hard lines?

 

[Pin_Head]

Update: fuel pump pushing plenty of fuel. When I run engine at idle, fuel in glass ranges between just above and below the dot on window. When I run engine at 2000 ish rpms, fuel level runs all the way to the bottom of the glass before it begins to replenish. Is there a filter IN the stick aiding carburetor?

This isn't a meaningful measurement of the fuel delivery capacity because your engine doesn't need much fuel when it is sitting still in your driveway. You may or may not have a screen over the inlet at the carb. If you took the fuel line off to check the fuel delivery, you could look inside with a flashlight and see if there was junk after taking the threaded inlet fitting off the bowl.

 

[76classic]

No screen inside inlet or outlet. This is a quandary. Good fuel volume from pump.
Gonna bring it back to the carb guy and ask him to see if float is sticking.

 

[mwebfj60]

Good stuff in the above posts..thought I would throw this in the mix..There are two adjustments on the float, one for fuel bowl level and one that dictates how far the needle is allowed to open from it's seat when the float is down. Perhaps the second adjustment is too tight...

 

[Solace in Solitude]

I understand your frustration...

But, to be clear, you asked for suggestions/help...

You are wasting people's time when you don't follow instructions or answer even basic questions...

Good luck.