1951 8N hard first start

[Tom Massachusetts]

My 8N does not start cold unless I cover the intake with my hand. The choke works fine and after it starts it runs good. I put another carb on off my other 8N and it starts just fine. I have gone through the carb, cleaned it out, blew it out, adjusted float level and it still will only start cold, room temp not outdoor cold, with a shot of start fluid or hand choke. What am I missing?

 

[RogerinIowa]

Choke plate may be not sealing quite
enough or plate could have openings in it

 

[deanostoybox]

There is a spring that holds the flapper on the choke plate closed. If that spring is missing it will do that.

 

[Tom Massachusetts]

Just checked and the choke plate closes good and the spring on the plate is there.

 

[showcrop]

What does you spark plug reading tell you about the gas?

 

[Tim PloughNman Daley RIP]

...it still will only start cold, room temp not outdoor cold... Hmmm? Did you perform the Fuel Flow Test first B4 anything else? I'd have your battery tested first.
A weak or dead battery will surely give non-starting issues, especially in cold temps, but regardless, if weak or dead will give starting issues. Take the battery to a
good starter/alt shop and have them test it on their special machine under load. When specific gravity drops, cell gets depleted, electrolyte drops. If you have an OEM
Marvel-Schebler TSX-241 Carb, I will rebuild it for you. If carb passes Fuel Flow Test, fuel isn't the problem. Did you rebuild the carb with new Main Needle & Float
Valve, set float to 9/32 or 1/4? If using the new style float valve and seat, is the extra clip attached and correct? Once you rebuild the carb, put settings to OEM
manual Specs.

Tim Daley(MI)

 

[Tom Massachusetts]

IT will NOT start at room temp, good fuel flow at carb drain, turns over good, 12v conversion. Runs good after start, good power. Just has this starting problem. Starts fine with my other carb from my '48 8N.

 

[Tom Massachusetts]

Yes I set the float at 1/4" and it has the clip on the needle.

 

[DennyD]

I agree with Tim regarding the need to check the battery. These tractors seem fussy about having a charged battery for easy starts. (In my case, my 8N came with a bum alternator from a botched 12V conversion, and the alternator wasn't charging the battery, so starting was nightmarish in chilly temps.)

 

[Tom Massachusetts]

It cranks fast with the 12v and starts good with the other carb.

 

[showcrop]

(quoted from post at 07:12:13 02/21/23) IT will NOT start at room temp, good fuel flow at carb drain, turns over good, 12v conversion. Runs good after start, good power. Just has this starting problem. Starts fine with my other carb from my '48 8N.

What does your spark plug reading tell you about the gas?

 

[Jim L WA]

Tom, I would be curious how your suspect carburetor works on your '48 8N.

 

[Tom Massachusetts]

Thats a good question. I should try that .

 

[Tom Massachusetts]

(quoted from post at 13:47:28 02/21/23) Tom, I would be curious how your suspect carburetor works on your '48 8N.

ust put the 51 carb on the 48 and had the same problem. The problem seems to follow the carb.

 

[deanostoybox]

''Just put the 51 carb on the 48 and had the same problem. The problem seems to follow the carb.''

Something I have run into a couple of times is a warped throttle body and/or warped fuel bowl. Gasket seals around the edges but not in the middle. Air can leak from the bowl vent past the venturi. Or a torn gasket in that area. Another possible air leak could be if the sintered bronze drain in the bottom is missing.