Fuel Flow

[Anonymous-0]

I have a questions about fuel flow.

Tractor is '49 8N Front Mount, 12V


My question is when you remove the drain plug at the bottom of the carb how fast is fuel supposed to run out of it?

Real problem is tractor started right up, ran 20 min and died suddenly. No gasping or sputtering.

Checked spark and got "blue snot athority" over 3/16" to quote someone. At least on 3&4. Also jumped ignition sw just in case. No start.

Open carb drain and fuel ran out for at least a min. Not dribbling but not exactly gushing either. I did have clogs ~50 hrs ago and replaced tank valve & carb elbow.

Thanks as always for your help.

Phil

 

[Mike OH]

"My question is when you remove the drain plug at the bottom of the carb how fast is fuel supposed to run out of it?"

Kind of like a cow p-n on a flat rock. Someone once timed how long it took to fill a known size container..... memory doesn't serve me just how long that was, but I don't suspect fuel flow is your problem.

"Checked spark and got "blue snot athority" over 3/16" to quote someone. At least on 3&4"

This is probably your problem. Must have good spark on all four. Check your plugs and wires on one and two.

 

[R Geiger]

(quoted from post at 00:27:15 05/28/13)
I have a questions about fuel flow.

Tractor is '49 8N Front Mount, 12V


My question is when you remove the drain plug at the bottom of the carb how fast is fuel supposed to run out of it?

Real problem is tractor started right up, ran 20 min and died suddenly. No gasping or sputtering.

Checked spark and got "blue snot athority" over 3/16" to quote someone. At least on 3&4. Also jumped ignition sw just in case. No start.

Open carb drain and fuel ran out for at least a min. Not dribbling but not exactly gushing either. I did have clogs ~50 hrs ago and replaced tank valve & carb elbow.

Thanks as always for your help.

Phil

It should fill a pint jar in 2 to 3 minutes.

 

[GB in MT.]

(quoted from post at 11:05:01 05/27/13)

(quoted from post at 00:27:15 05/28/13)
I have a questions about fuel flow.

Tractor is '49 8N Front Mount, 12V


My question is when you remove the drain plug at the bottom of the carb how fast is fuel supposed to run out of it?

Real problem is tractor started right up, ran 20 min and died suddenly. No gasping or sputtering.

Checked spark and got "blue snot athority" over 3/16" to quote someone. At least on 3&4. Also jumped ignition sw just in case. No start.

Open carb drain and fuel ran out for at least a min. Not dribbling but not exactly gushing either. I did have clogs ~50 hrs ago and replaced tank valve & carb elbow.

Thanks as always for your help.

Phil

It should fill a pint jar in 2 to 3 minutes.

b:39432ad70a][i:39432ad70a]

Just as stated, by R G, and that is from the carb bowl drain plug!!! Fuel flow through the sed. bowl, and tested at the fuel line end, should be 1 pint @ about 1 1/2 mins' flow rate!!!

Any flow dif., than that....you still have a fuel flow problem.

Pull the elbow screen, check from there all the way back through the fuel line, sed. bowl, and finally the tank screen it-self. (Top of the seb. bowl...inside tank.)

Once rust and debri, gets into the fuel tank, you will be chasing fuel clogs, until the tank is properly cleaned out.!!!

Gary


[/i:39432ad70a][/b:39432ad70a]

 

[Anonymous-0]

If you clean all the screens as GB said and it still is a little slow, take the fuel bowl assembly down from the tank - run a thin wire through the holes. There are two of them, could be a piece of junk cloggin it.

 

[Dell (WA)]

Phil.......you write......"ran 20 min and died suddenly".......suddenly is almost always ELECTRICAL!!! 20-mins is usually yer weaksister ignition switch. Iff'n you have 3/16" of blue snot sparkies on 1, you'll almost have 3/16" on all 4.

Ennytime you have "starting issues", change yer sparkies. NO ARGUE!!!!
Recommend AutoLite 437's gapped 0.025".
Don't throw yer FLOODED sparkies away, just clean'n'dry them, one-atta-time in HOT running engine and save'um fer the next time. (and there will be a next time)

You write......."Open carb drain and fuel ran out for at least a min. Not dribbling but not exactly gushing either"........while the self-admitted "clogs" is not a ringing endorsement of quality fuel flow, you could be encountering the effect of gastank "VACUUM" caused by a CLOGGED breather vent on the domed top of yer new gastank. (that you can NOT gitt-too without removing the tank again) Just loosen yer gascap and check yer flow again. Simple, eh? ........HTH, Dell, yer self-appointed sparkie-meister at the foot of 14K Mt Rainier

 

[Anonymous-0]

Thanks everyone!

Some follow up data (and yes Dell I will get some new plugs for "next time")

Fuel from carb drain easily filled a pint in 2 min so seem unlikely to be the issue. I had opened the gas cap when it died and no change so vacume unlikely

As for electrical that was my first thought but if I have good sparks (now checked on all 4) what else is there to the electrical?

Re ignition switch I have been lurking long enough to know it can be an issue so second thing I did when it died was jump switch with gator clips on ~5" #20 wire. No change. Presumably if jumped can't be an issue.

Today it did start and has idled for 30 min without an issue.

 

[Dell (WA)]

Phil.......5-in of #20-ga wire is like another RESISTOR in the ignition circuit and excess resistance will cause weak sparkies. I can guarantee you that even 5-in of #20-ga wire is at least 1-ohm, which is about same resistance of the "infamous ballast resistor". BTW, the wire to the top of the squarecan ignition coil is #14-ga. .......Dell, yer self-appointed sparkie-meister

 

[JMOR]

(quoted from post at 16:56:57 05/27/13) Phil.......5-in of #20-ga wire is like another RESISTOR in the ignition circuit and excess resistance will cause weak sparkies. I can guarantee you that even 5-in of #20-ga wire is at least 1-ohm, which is about same resistance of the "infamous ballast resistor". BTW, the wire to the top of the squarecan ignition coil is #14-ga. .......Dell, yer self-appointed sparkie-meister

Come on Dell! Retired engineer, master wiring harness builder, self-appointed sparkie-meister, THE KARNAK of all things electrical, can surely find a wire table. 10.2 Ohms per 1000 feet. That comes out to 4/1000 th of an Ohm for 5 inches. 0.004 Ohm. 20 GA copper wire. SHEESH!

 

[Spooke]

(reply to post at 11:47:43 05/27/13)

See how long it will take to flow a gal.

You could get a petcock to go in the carb bowl to eliminate fuel flow issues at the time it acts up. I would go for the kill and time a gal. are more flow.
It takes time for trash to block screes that may sleep at a static stand still.

You could get a real spark tester to eliminate spark instead of a poor mans 3/16 guess. A guess is what it is it does not confirm good spark you can bank on it no matter how many times wanna be mechanics post it.

Test are to confirm operation of a system so you can move on to another its called elimination . Bad advise keeps you hung up you never eliminate you fiddle fart around and stay stuck.

Take it one step at a time. Eliminate each system with the corect tools then move on to another don't guess.