38-41 ford 9N tractor

I had to change a distributor cap and since then I seen to be having a vapor lock problem. It will start good and run a few minutes, then shut down. It will start right back but will shut down again. I would really appreciate any suggestions.

It is not vapor lock. By definition, a gravity flow system cannot vapor lock.

Verify proper fuel flow by removing the plug in the bottom of the float bowl and turning on the fuel.

If fuel flow is not adequate clean all three strainers.

Dean

You will get a lot more answers down in the 9N/2N/8N forum. That said check that you have a good spark that will jump a 1/4 inch gap and that you have a good steady flow of gas out the drain plug at the bottom of the carb. By the way the reason it is called a 9N is because of the first year it was to be sold in which is 1939

remove the drain in bottom of carb and make sure it is flowing for over a few minutes. if it stops flowing remove the gas cap. if flow returns then you may have to either get a new cap, or drill a small hole in the one you have. if removing the cap makes no difference then the screens probly need cleaning or replaced. if screens are clean then you may have sticking needle and seat----carb rebuild time. IF you have an inline filter---either get rid of it, or make sure it is for the correct application.

Bad coil is the most likely culprit.

If you don't have a coil with a built in resistor, be sure you have a resistor between the coil and the distributor if it has been changed to 12 volts.

Dean,
Interesting you say that. On another forum a few months ago, someone was having vapor lock problems on a gravity fuel system. I responded saying, like you, That is impossible. Also impossible to vapor lock if fuel pump is in or neat fuel tank where it is pushing instead or sucking where vapor will occur. A fuel pump can't pump vapor, only liquid. You know, no one agreed.

There's NO such thing as a 12 Volt coil with "a built in resistor". They are simply wound with more turns in the primary winding.


AND the replacement coils sold as "12 Volt coils" for the old front-mount distributor "N's" REQUIRE the OEM ballast resistor that was used with the original 6 Volt system to remain in place!

Hank.......there are 4-common runtime issues with the 4-nipple frontmount dizzy.
1) runs fer about 1-min and quits; restarts innna 'bout 5-mins; BAD condenser
2) runs fer about 5-mins and quits; restarts innna 'bout 5-mins; clogged in the tank filter
3) runs fer about 15-mins and quits; restarts innna 'bout 30-mins; BAD weaksister ignition switch $10, cheap)
4) runs fer about 1-hr and quits; restarts innna 'bout 4-hrs or overnite cooldown; BAD squarecan ignition coil

Don't fergitt the dome tank vent under the hood gitts clogged up by mud-dobbers and VACUUM will stop yer gravity fed fuel system. Just un-snapple yer gas capple. Simple, eh?

You do know ittza 2-bolt, 15-min job to remove yer frontmount dizzy and change the points (0.015") on the kitchen table, don't you? You can NOT re-install outta time 'cuz of the "off-set" drive scheme. Just un-snapple yer capple and letter dangle, simple eh?

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)

Recommend you squander $25 (cheap) for the I&T FO-4 manual. It even has pictures fer the reading challenged. .......Dell, yer self-appointed sparkie-meister

They were wrong.

Dean