Won't start :(

[8N-MW]

I have a 1948 Ford 8N, 6V, Front Distributor.

It [i:58ce2bd3cd]did[/i:58ce2bd3cd] run several months ago. I lubricated everything, changed the oil, cleaned the air filters, put in new points, plugs, charged the battery, etc... The tractor [i:58ce2bd3cd]has[/i:58ce2bd3cd] started since I've done that - and it ran good. So, it's run with these plugs in and with these points.

However, I can't get it started now. It cranks but won't fire up.

As far as electrical....
*Battery is 100% charged with clean terminals
*Electrical connections are good
*Bypassing the starter doesn't help

As far as fuel/air....
*It has fuel and it is getting to the carb
*Fuel filters are good
*It's not flooded. I've drained the gas out of the carb and cleaned off the spark plugs to no avail
*Spraying starting fluid into the carb doesn't help
*I haven't monkeyed with the carb - it ran on it's current setting

What's the next step?[/list]

 

[Bruce (VA)]

Do you have battery voltage at the coil?

Get out your spark checker and see if you
have a spark that will jump 1/4".

Chances are your points are corroded.
75 Tips

 

[8N-MW]

(quoted from post at 15:42:15 11/08/15) Do you have battery voltage at the coil?

Get out your spark checker and see if you
have a spark that will jump 1/4".

Chances are your points are corroded.
75 Tips

There is voltage at the coil and my plugs have a strong spark. I just recently put the points in. Like I said, it has successfully started and ran with those points. However, they've only seen a few hours of a running engine - maybe 4. So I don't think they're corroded.

 

[8N-MW]

Also,

I don't have a compression tester but I can feel air blowing out the top if I take a plug out.

 

[Bruce (VA)]

" There is voltage at the coil "

What is it? It should be battery voltage, points open & about half that, points closed.

" have a strong spark."

How do you know that? Will it jump 1/4" or not?

" So I don't think they're corroded. "

Points do not corrode from too much use. They corrode from lack of use. You said " It did run several months ago.". It's easy for points to corrode in a couple of months.
75 Tips

 

[8N-MW]

(quoted from post at 17:05:21 11/08/15) " There is voltage at the coil "

What is it? It should be battery voltage, points open & about half that, points closed.

" have a strong spark."

How do you know that? Will it jump 1/4" or not?

" So I don't think they're corroded. "

Points do not corrode from too much use. They corrode from lack of use. You said " It did run several months ago.". It's easy for points to corrode in a couple of months.
75 Tips

It tests at 7.1V on the battery and at the coil. The spark jumps the correct gap and if I swap plugs to 1/4" it will also jump that. I last had it running the first weekend in September, I can't imagine that would corrode points, would it?

 

[Bruce (VA)]

" I last had it running the first weekend in September, I can't imagine that would corrode points, would it? "

Possible, but not likely.

" It tests at 7.1V on the battery and at the coil."

That's points open. What do you get w/ points closed?

Sounds like you have a decent spark.

Tell us how you checked fuel flow at the carb.

Have you tried removing the breather hose & using starting fluid in the carb throat?
75 Tips

 

[8N-MW]

Thanks for all the help. I guess I don't know with points closed.

As far as fuel flow, I can open the sediment bowl and take that bolt out of the bottom of the carb (which is the original one, starts with an S, can't think of name), fuel will flow continuously.

 

[Bruce (VA)]

OK, fuel sounds good.

Check voltage w/ points closed & try starting fluid.

Post back w/ results.
75 Tips

 

[Den N Ms]

Hawkmiles,You might try making up a 6" jumper with alligator clips on each end and jump across the ballast resister to give the coil full battery voltage just to start it up.Jump the two terminals where each wire hooks to together with the jumper wire,then remove it when it starts.

 

[Dell (WA)]

hawkmiles........yeah, keep yer itchy-twitchy fingers off'n them handy-dandy carb tweek'ems. The 4-nipple frontmount points (0.015) are notorious fer SLIPPING closed, specially fer neubies shadetree wanna be mechanics. 2nd, the points adjusting screw is a SHORT #8-32x3/16. 3rd, surprizingly enuff, BRASS screws wear out so you may wanna consider replacing it. CAUTION: most hardware stores sell 8-32x1/4 and will catch on the centrifugal advance weights under the point mounting plate. TIP: go to yer local FORD automobile dealer fer NEW 8-32x3/16 screw. They gott'em but you'll haffta argue with new parts clerk. Often times they wanna know what year yer car is; ANSWER is: old Ford convertible. Don't mention tractor, simple, eh? .........HTH, Dell, yer self-appointed sparkie-meister

 

[pinball]

I went to work on my 8n yesterday. Had a hard time starting it. Checked everything. Had voltage, spark, gas, had it all. Finally I looked at the linkage on my carb to the governor. Then I discovered I was using the throttle linkage backwards. When I thought I was giving it maximum I was actually shutting it off. On my tractor you always put it about 3/4 throttle, pull choke out all the way and it will start right up. Must of been my old timers I guess. norm

 

[JimNC]

Hawkmiles, I recently went through the same thing on my 8N with the side mounted dist., done everything in the book then finally found points were closed up. Also, once it would not start after setting awhile, changed plugs and it fired right up. I've almost pulled all my hair out once or twice trying to get it started when I knew it SHOULD. If you shot starting fluid in and it did not even pop, either the intake is filled with a mouse nest or you are not getting spark when the plugs are under pressure, they will spark in normal atmospheric pressure but not under 100psi or better. It takes 3 things to make it start, air, fuel and ignition source and some compression of course. Which one are you missing?

 

[8N-MW]

(quoted from post at 19:49:48 11/08/15) hawkmiles........yeah, keep yer itchy-twitchy fingers off'n them handy-dandy carb tweek'ems. The 4-nipple frontmount points (0.015) are notorious fer SLIPPING closed, specially fer neubies shadetree wanna be mechanics.

No choke for me anymore, you folks set me straight on that quite a few months ago. As far as the points slipping closed (I [i:3622761525]am[/i:3622761525] definitely a newbie shadetree wanna-be mechanic, by the way), what would that mean? Wouldn't that cause no spark to occur at all? How might one diagnose such an issue?

(quoted from post at 21:16:23 11/10/15) Hawkmiles, I recently went through the same thing on my 8N with the side mounted dist., done everything in the book then finally found points were closed up. Also, once it would not start after setting awhile, changed plugs and it fired right up. I've almost pulled all my hair out once or twice trying to get it started when I knew it SHOULD. If you shot starting fluid in and it did not even pop, either the intake is filled with a mouse nest or you are not getting spark when the plugs are under pressure, they will spark in normal atmospheric pressure but not under 100psi or better. It takes 3 things to make it start, air, fuel and ignition source and some compression of course. Which one are you missing?

I'll have to do some more research on the points closing. Thanks for the info.

[b:3622761525][u:3622761525]Update[/b:3622761525][/u:3622761525]
I have not tested the compression yet, but I have a compression tester coming on Wednesday. I've tried swapping out the spark plugs (once I flooded it) to no avail.

I've also done a complete carb rebuild. The float was too high, I adjusted that back down to the 1/4" it was supposed to be at. I did new jets, everything. Interestingly enough, my carb literally had no main jet - there was nothing under the main discharge nozzzle.

I've also tried putting oil in the cylinders. I'm running 5W-30 up in Minnesota, it's about 30*F right now.

I've tried ether in the carb (breather tube is off), jumping 12V to the starter, praying to god....everything.

So, I am pretty darn confident it is not fuel related. I have a full tank of fresh gas, ventilated properly, with good filters and screens, no added fuel filters, getting plenty of gas draining out of the carb if I take the drain plug out.

As far as spark, I do have strong spark. It's a blue spark and will gap 1/4" easily. Perhaps it has spark at the wrong time? It's a front-mount distributor, which I've recently replaced points in.

As far as compression - I'm sure it's low. I'll know exactly how low on Wednesday.[/b]

 

[8N-MW]

I don't think I have a problem with points. As I rotate the back of the distributor, the points close completely shut and open to 0.65mm. They don't appear to have any corrosion or burning either.[/img]

 

[Royse]

Hold the palm of your hand over the carb throat while trying to
start it. It should suck your palm right to it. This will choke it
and just might make it start even when ether doesn't get it.
You will probably get some gas on your hand when you do that.

 

[JMOR]

Re-set point gap to 0.38mm. 0.65mm is too wide.

 

[NoNewParts]

(quoted from post at 18:07:41 12/26/15) Hold the palm of your hand over the carb throat while trying to
start it. It should suck your palm right to it. This will choke it
and just might make it start even when ether doesn't get it.
You will probably get some gas on your hand when you do that.

With known good spark and fuel on a previous runner, this is always worth a try.
Some Ford carbs have a little door in the choke flap.
If it is broken, missing or not working properly, on a cold day you can't get enough 'choke' and it won't go.
Let the battery charge up, let it sit for a bit, put [i:abe58fcbd5]new[/i:abe58fcbd5] plugs in and do as Royce suggests. Post back

With all old tractors, get to know their quirks.
Had an Allis B, went thru, all good. Warm or cold out, first start it would crank briskly but...nothing. A second of holding my hand over the air cleaner intake, instant start.
Went thru everything again....'There is nothing wrong here'
shrug...I hold my hand over it

 

[8N-MW]

I did perform compression tests. To be fair, it wasn't at normal engine operating temperature (because it won't start). It was about 25° in the garage, but it had a fully charged battery and an oil pan heater on it. All the pkugs were out and I followed all instructions as far as throttle, choke, etc.. Here are the results (front to back). The first number indicates where it went to immediately when I turned it over, the second number is the next reading I got. The cylinder would peak at that.

1: 60/90psi
2: 75/90psi
3: 75/90psi
4: 60/90psi

Any thoughts on the results of this?

I have the (front mount) distirbutor off, shortening my point gap; there was a discrepancy in manuals and one indicated, in inches, the equivelant of 0.65mm (I only have a metric gauge). I've brought it down to 0.38. I have the tool from OldHokie (highly recommend) and will be verifying the timing is correct. At that point, I'll put it on and attempt to start with some of your tricks; like choking the carb with my hand.

Thanks all.

 

[Royse]

90 PSI is what Ford spec'd for minimum.
I would think it would still start and run there.
Maybe not as easily, but it should start.

The 0.65mm point gap would be correct for a side
mount distributor, front mount uses the smaller gap.
That may be where the discrepancy came from.