Has spark, has gas, WON'T START!

[Big Dave Daddy]

Last week the 49' ran and started good. Mowed 5 acres.
Yesterday, no start. Checked everything I know about, points are gapped, cranks good, and each plug was removed and checked for spark while cranking. Fuel seems plentiful, but won't fire on starting fluid either. Voltage is present going to the coil, and also at the springy thing on bottom of the coil.
Note: Amp gage is not working, but I see the plugs firing regularly. How, or is any of this related to the not starting?
PLEASE HELP!!!

 

[Dell (WA)]

Dave......PROVE you have good sparkies with a calibrated sparkie tester. Take enny ol'sparkie and bend the side electrode out for a full 3/16" gap. Ground the metal shell to convenient bracket with clamp. Plug enny sparkie wire to yer testers and crank yer engine with ignition switch ON. Do the sparkies jump the 3/16" gap with blue-snott authority??? or are they wimpy yellowish-orangish poor excuses? ...or... NO SPARKIES at all???

Iff'n you don't know what to do after that, ask?

Ennytime you have starting problems, CHANGE yer SPARKIES. Ya done FLOODED 'em and need to be clean and dry. Recommend NEW AutoLite 437's gapped 0.025". Don't throw yer flooded sparkies away, just clean'n'dry 'em one-atta-time in HOT running engine as save'em fer next time you have hard starting. Works every time.......Dell, yer self-appointed sparkie-meister

 

[gahorN]

Also.... don't forget..... gas, air, and fire (spark) must occur at the proper TIME in order to run an internal combustion engine. You didn't by chance, route your new spark plug wires to the wrong cylinders...???

 

[Bruce (VA)]

6v or 12v? It could make a difference troubleshooting.

Well, if it has spark at the right time, fuel in the right mixture & compression, it must be running!

Seriously, it didn't lose compression overnight, so you missed something in the checks.

Start over. Check the spark like Dell advised, check your plug wires & check for fuel by removing the bolt in the carb bowl. Jump it or pull start it in case you have a weak battery or dragging strter pulling too much current from the ignition circuit.

 

[Anonymous-0]

Check compression as a valve or three could be stuck open.

 

[Anonymous-0]

I will try a large gap tonight when I get home, though the plugs did not appear to be fouled. The plugs were not wet or sooty. More of a light tan color, which I thought was correct....

 

[Big Daddy Dave]

Bruce, the tractor is still 6 volt system, been running great, previously.
I agree, it must be running!!!!, but its not.
Tonight I will double check everything.

 

[Big Daddy Dave]

I'll measure compression tonight, though last night I did the "finger in the hole" test and I felt pretty good pressure.
Same wires as last week, and I have not changed any parts.
Voltage present in and out of the coil, springy thing is making contact. Points gapped properly and observed with an Ohmmeter while opening and closing.
With the 4 plugs setting on top of the head, each one grounded, I can see them all firing. Plenty of fuel "seems" to be available at the carb, though starting fluid would not even make it fire...Hmmmmm

 

[souNdguy]

Sometimes gas can foul them.

If you have spark.. and she won't pop on ether.. then compression is the next issue.. however.. it's harder to 'fix'.. so doublecheck spark first..

soundguy

 

[Anvilheadtexas]

Big Dave, I seem to have the same problem with my "49 12 volt. She usually is more stubborn the wetter or more humid the air is. If I leave her out over night - there is no chance of starting. Like Dell and them suggest, I have done the large gapped spark plug test and always I have spark. Of course, I am no expert on just how strong a spark is, thinking about it now, I think that is where I will look next time. I would recommend you do the same.