Attention SparkieMiester (Dell) please help

Hey sparkiemiester!!! I'm totally stumped and need your expertise. Working on trying to get a 9N running for somebody. Was sitting over a year. Here's the info...

12 volt negative ground.

New battery fully charged, new neutral safety switch, new key switch, new OEM dash resistor, new ceramic blob resistor. Starter motor turns engine over fine. Getting 12V to coil. New points gapped to .015... blue streak brand good stuff. New condenser, good copper strip to connect points. New coil. Verified by test lightthat points are opening and closing. New plug wires, cap and rotor. Pig tail on coil is making contact on brass screw and metal bendy tab is making contact on cap metal spot. Wired firing order 1,2,4,3. And I have spark that will jump 1/4 inch gap bright as the sun all day long... and of course new auto lite 437's gapped to .025. Tank was drained boiled and rinsed with gas and drained and re filled with fresh gas. New fuel line, sediment bowl and carburetor. We have positive strong suction on carb verified by hand hickie over air inlet. Choke is working. Pull the plug out the bottom of the carb and nice steady flowing stream of fuel.

The symptom is that as I hit the starter button engine turns over and rumpa rumpa .... and one pop backfire out the carb and that's it.

What am I missing? The only thing I did not check is for engine compression.... my gauge broke the other day but this tractors engine was just re built not too long ago (5years or less). So I assume it to be over 90PSI it does have enough to blow my finger off a sparkie hole.

For the life a me this one has got me stumped?! Any ideas or suggestions you could offer would be super!

Thanks o great sparkiemiester!

I would recheck the spark plug wire
firing order, just to be sure...

Bypass ceramic bolb resistor and try it.. Report back.

Junkie.........compression is NOT yer issue. Timing is maybe an issue; ie...1-pop... Ya say ya replaced the sparkies, may need to consider replacing them AGAIN!!! With all that crankin' ya FLOODED 'em. Don't throw 'em away, just clean'n'dry 'em one-atta-time in HOT running engine. And save'um fer the NEXT time. Fresh gas is always a good start, and fer S&G's, I'd adjust the down-pointing mainjet to 2-turns and LEAVITT!!! And makin' a WAG on yer side-pointing idlemix to 1/4-turn. 1/3-throttle shuld gittcha started. After about 15-mins, ya kenn re-adjust yer side-pointing idlemix fer FASTEST idle, NOT SMOOTHEST idle. Understand the difference??? Ennythang under 500-rpms is good to go. I know yer 9N ain't gotta "proofmeter" like 4-speed 8N's do butt make a guess. Just to make ya feel good, I have a 6-volt transistorized tachometer that I hooked up to my eazy starting 52-8N and got the idle down to 375-rpms. I also use it fer my semi-race 1969 BMW 2002 with dual Webers that will turn 7500-rpms. Beat the heck outta the OEM Solex anti-smog carbie. And believe it or not STILL passes the tailpipe smog test and gitts me 25-mpg....... HTH, SparkieMeister Dell

Thanks all very much...

Dell I am on the way to go re stock my supply of sparkies.

I will re check plug wires

Will also try with bypassing the ceramic blob resistor as others suggested.

Will post back

A compression test might tell you that you have stuck valve or two.

9njunkie,I'm with R Geiger,Check compression and look for stuck intake valves.(backfire out the intake)

9njunkie,I'm with R Geiger,Check compression and look for stuck intake valves.(backfire out the intake)

Exactly what I was going to say!

Zane

Everyone says these will run on two cylinders & I agree with them, so the question is, are all the intake valves stuck or at least 3 of them? :roll:

Google JMOR's Wiring Pictograms and see all the CORRECT ways to wire these old N's then download a copy for yourself. Why do you have TWO resistors? Throwing a boatload of new parts into a problem may or not eventually stumble yer butt onto the root cause unknowingly so why not do a systematic, root cause problem solving procedure? Just saying baby steps, basics first -


Tim Daley(MI)

Everyone says these will run on two cylinders & I agree with them,If two plug wires are crossed or even removed.But if you have a intake valve or two hung open and backfiring out the intake of the carb all the raw fuel is burning in the intake manifold and little or none is getting to any good cylinders also the reverse flow of air through the carb and no vacuum to pull fuel air mix into the cylinders .

When I changed my 8N to 12 volt I used that ceramic resistor,Had same problem take that off,just use the OEM resistor.
The wiring instructions aren't real clear about that.It says use the ceramic if needed, what does that mean.They
shouldn't even put that ceramic one in the kit,you don't need it.

UPDATE:

So we went though and took everyone's advice. Checked compression... good, checked plug wires and firing order ...good, changed sparkies .... so we are god there too.

Still no change. So just for ha ha's double checked suction on intake with carb off. Had some suction but felt possibly weak to me.... compared to another 9N tractor here and noticed stronger suction!

Bingo 2 out of 4 intake valves were stuck. Pulled covers off and could see... and better hear what was going on. Intake's on cylinders 3 and 4 no go up n down. Soaked the cylinders with my fav MMO. We now have verified movement on all valves now. Worked the engine over for a while to run as much MMO out of the cylinders as possible then will re assemble and try to fire again.

Thanks all very much for all the great advice. Will post back in a day or two when I get it back together and hopefully running.

If you had intake valves stuck open, there is no way you would get good compression. Just saying.

Hope that solves your problem.

(quoted from post at 12:49:45 07/18/17) UPDATE:

So we went though and took everyone's advice. Checked compression... good, checked plug wires and firing order ...good, changed sparkies .... so we are god there too.

Still no change. So just for ha ha's double checked suction on intake with carb off. Had some suction but felt possibly weak to me.... compared to another 9N tractor here and noticed stronger suction!

Bingo 2 out of 4 intake valves were stuck. Pulled covers off and could see... and better hear what was going on. Intake's on cylinders 3 and 4 no go up n down. Soaked the cylinders with my fav MMO. We now have verified movement on all valves now. Worked the engine over for a while to run as much MMO out of the cylinders as possible then will re assemble and try to fire again.

Thanks all very much for all the great advice. Will post back in a day or two when I get it back together and hopefully running.

Click to expand...

hat begs the question of how intakes could be stuck (presumably open, as the cam would surely push open, so not stuck closed) and still have a good compression test?

Looks to me that cylinder three and four were stuck in the closed position. Everything moving now though.

(quoted from post at 13:41:53 07/18/17) Looks to me that cylinder three and four were stuck in the closed position. Everything moving now though.

Click to expand...

Well, so much for this theory: "But if you have a intake valve or two hung open and backfiring out the intake of the carb all the raw fuel is burning in the intake manifold and little or none is getting to any good cylinders also the reverse flow of air through the carb and no vacuum to pull fuel air mix into the cylinders ."
Just kidding Den! :wink:

(quoted from post at 11:41:53 07/18/17) Looks to me that cylinder three and four were stuck in the closed position. Everything moving now though.

Click to expand...

How would a valve get stuck in the closed position on a flat head? If theyr were stuck closed maybe the cam was not turning at all?

Yeah I agree JMOR... don't quite understand 100 percent myself. Here is what I observed once I removed both valve covers... the four valves (intake and exhaust) on the front of engine (cylinders 1 and 2) were all moving up and down when engine turning over like they should.

The rear valves (for cylinder 3 and 4) only the exhaust valves were moving up and down when engine cranking. No movement at all on the intake valves for cylinders 3 and 4. Could also hear a noise now with valve covers off that I could not hear before.

Once I observed this my solution that I used was to use a generous amount of MMO (8CC's) inserted down each sparkie hole on 3 and 4. The I exercised the engine until all the valves were free moving up and down. It did not take much...my best guess is they were only lightly sticking. Also the "bad" noise I heard prior went away now that everything is moving.

Have to be away for a day tomrrow will re assemble in a day or two and hopefully this fixes it.

Best wishes for runner soon!