engine cuts out

[cabinkiotio]

Finally got my 51 8n out of the shop for it's first run outside of the barn. There is s slight upgrade on my road and at half throttle it started to die out. I gave it more throttle and it recovered. a little further on it did the same thing sow I headed back to the barn. I replaced the points rotar, condenser new plugs and all wiring looks ok. Checked the timing 4 btdc. Took out the carburetor plug and there seems to be plenty of gas. I can run it a 2200 rpm's and it will run fine but when under a load it seems to cut out. I have the down pointing high speed needle adjusted to two turns out. I had previously overhauled the carburetor and I know it is really clean and has a overhaul kit from mikes carb. The governor is a novi fly weight style and I am pretty sure all the linkage is adjusted correctly. The governor spring is not to tight or to loose. I am at the end of my road with this tractor. Please help.

 

[Den N Ms]

Cabinkiotio,You say,I have the down pointing high speed needle adjusted to two turns out. You could try adjusting it to 2 1/4-3 turns and see if it runs better.Open it 1/4 turn at a time then check how it runs.The 2 turns and leave it dosen't always work for different carburetors , engines or weather/elevations.

 

[cabinkiotio]

I will give it a try. The tractor is at my cabin and will not get there till the middle of next week

 

[Royse]

It will not hurt to try turning the main adjustment out a bit more.
Other than a possible fuel economy hit.
However, if you have to have the main adjustment two turns
out or more, you still have something wrong with that carb.
Assuming it is an original Marvel Schebler carb for an N series.
Ford service manual page 57, paragraph 223e says 1-1/4 to 1-1/2
Obviously there are variables involved such as engine wear and
compression, but most of them should be less than 2 turns.

 

[showcrop]

What height do you have the float valve adjusted to?

 

[Tim PloughNman Daley]

When you rebuild the carb, those settings are the starting point. You have to get the engine good and hot up to running temps then make carb adjustments and often this takes 2 or 3 tries to hit it right. You just don't set the main at 2 turns and leave it and the other two screws. Set the MAIN at 2 turns initially, leave it alone, and then proceed with the side idle screw-you can find the procedure here by searching the archives. If you get the MAIN out 3 or more turns, there is something not right. You need to set carb settings while under load -do you have a Proofmeter on your 8N? If not, put in 1st gear, foot on brake, and carefully have a helper try to adjust while slight throttle up.

Tim

 

[HFJ]

at the risk of becoming the proverbial one topic poster, i am at the point where i suspect every time something like this happens, it's caused by too little gas in the tank trying to go thru the reserve pickup. the first thing i'd recommend is pouring another 2 gallons of gas in the tank. it's essentially free to try, as you're gonna burn that gas anyway. beats buying new parts when the only part with a problem is the sediment bowl, and simply using the main pickup instead of the reserve, along with enough gas in the tank, fixes it.

 

[cabinkiotio]

The carburetor floats are set to if I remember 1/4 inch. . I think it is set ok. When I get back up to the cabin I will check the fuel line again for flow. Against my better judgement I installed a inline fuel filter. Now that I am thinking about it when I turned the fuel back on the filter only had a little gas in it. I think the filter is a fram g1or3 see through. I know a lot of my fellow 8n users think a inline filter is wrong. If there is gas in the carburetor and the floats are up that will close off the fuel from getting to the filter I think and please correct me if I am wrong.

 

[HFJ]

inline fuel filters are not the horror some make them out to be. my 2N has one, works fine. if gas can get to it, gas can get through it

yes, it's a closed system. as long as the bowl is full and the float is doing its job, there is nowhere for that air to go.