Carb issues I think ???

[LeeHulcher]

Ok Guys,
I am a lady in distress, My 52 8N starts and runs like a top, but only with a shot of starting fluid, and holding the choke full open. I have cleaned and rebuilt the carb, checked the points. I have fire to all plugs, cap and rotor looks good.
The only issue I can think of, is that the carb is not getting enough fuel because it runs with the choke pulled all the way.

So question(s) how much fuel coming out of the line is enough, a quick drip or a stream? Why will it start instantly with starting fluid, but not with out it? Is this a spark issue, a timing issue or a fuel issue?

Lady Lee

 

[Bruce (VA)]

Remove the bolt in the bottom of the carb. Turn the fuel on at the sediment bowl.

Will the stream fill a pint jar in less than 2 minutes?

Post back w/ the answer.
75 Tips

 

[Hobo,NC]

fuel issue...

 

[Dell (WA)]

Lee.......ittza fuel issue. Ya FLOODED yer sparkies, replace 'em. Recommend AutoLite 437's gapped 0.025. Don't throw 'em away, just clean'n'dry 'em, one'atta'time in HOT running engine. Learn how to adjust yer M/S carbie. Set the down-pointing MAINJET to 2-turns and LEAVITT!!! Adjust the side-pointing idlemix fer FASTEST idle, NOT SMOOTHEST idle. Understand the difference??? Usually will be about 1/8-1/4 turn. Remember the idlemix is BASS-ACKWARD. Out fer lean, IN fer ENRICH. Remember the starting drill, ignition ON, 2-rumpas on starter motor and a QUICK PULL on the spring loaded choke shuld gittcha started in all but the coldest weather. Cold weather, you'll haffta feather the choke after starting to keep it running. Shuld be steady idle running after 1-min.......Dell, yer self-appointed carbie-meister

 

[Tim PloughNman Daley]

I concur you have a fuel issue. The N-Series Tractor fuel system has three in-line screens before gas gets into the carb. Two screens are in the sediment bulb assembly as shown in my picture. The third is in the brass fuel inlet elbow on the carb itself. As Bruce(VA) said, first thing is to check that fuel flow is sufficient to the carb. There are two ways to do that, first is as he describes. With engine COLD, place a container, a coffee can will work, under the carb to collect gas. Next, remove the drain plug on the bottom of the carb, then open the FUEL SEDIMENT BULB VALVE TWO FULL TURNS. Observe if fuel flow is a nice and steady, almost a pencil-thick stream uninterrupted. If gas sputters, hesitates, stops and starts, the problem is in the screens. An alternate method is to place a container under the carb, loosen the fuel inlet line coming from the Sediment Bulb to the carb brass Fuel Inlet Elbow. Gently pull away and direct it down towards container. Then open sediment bulb valve 2 full turns and observe fuel flow is as described above. When you 'rebuilt' the carb did you clean that screen in the elbow or replace it with a new elbow? The other two screens in the bulb itself need to be cleaned then as well. The valve stem has a rubber 'seal' that will over time get chewed up and sometimes leak and/or cause malfunction issues. Tiny pieces can break off and make their way to the elbow. It maybe required to pull the sediment bulb off the tank to clean as the one screen is vertically attached to the inlet port that is tucked up inside the tank. New valve stems are available for under $10 and no need to purchase a whole new sediment bulb assembly. Use care with fuel line fittings and lines. They use a special thread size and always start the threads/fittings by hand. Never use rubber, nylon, plastic, aluminum, or copper fuel lines. Use the correct 1/4" steel fuel line available already custom bent exactly like the original. Try this and if problems are still apparent, we'll look into the carb itself.

Tim Daley(MI)



FUEL SEDIMENT BULB & SCREENS: