mechanic needs help

[holmes1442]

I am a mechanic at small shop that repairs everything from lawnmowerers to automobiles. I love old tractors and am in the middle of a restoration on my super c, but that is not my problem. I have a customers 51 8n here that i have replaced plugs, wires, rotor, cap, points, manifold, coil, and a lot of wiring. Carberator has also been rebuilt and we are still having a problem with it running properly, seems to flood out unless the fuel filter is almost empty and it doesnt like to rev up to max rpm. It runs sweet once it does but cant figure why it is hit or miss as to when it will run right. Help!?

 

[SPYDERLK]

Distributor bearings? Plugged breather in carb float bowl? Bad float or float valve? :confused2:

 

[murphy1244]

:welcome:

 

[murphy1244]

I am a mechanic at small shop that repairs everything from lawnmowerers to automobiles. I love old tractors and am in the middle of a restoration on my super c, but that is not my problem. I have a customers 51 8n here that i have replaced plugs, wires, rotor, cap, points, manifold, coil, and a lot of wiring. Carberator has also been rebuilt and we are still having a problem with it running properly, seems to flood out unless the fuel filter is almost empty and it doesnt like to rev up to max rpm. It runs sweet once it does but cant figure why it is hit or miss as to when it will run right. Help!?

What is the plug color?

 

[Briana03]

Welcome to TBN

I moved your thread to the Ford Vintage Tractors forum.

 

[Soundguy]

external add on fuel filters are a constant source of problem if the wrong type is used.

flooding out means float is not correct.. or the needle / seat is not correct.

that's no mystery.

once you address that.. manually goos carb butterfly to see what rpm you can get.

does gov pull back even with throttle set to max?

is throttle and springs and linkage at the gov adjusted to book spec? remember.. no preload or slack on the springs.

 

[EMB5530]

The floats on those carbs rub on the casting of the bowls and get little microscopic cracks that take in enough fuel to not float correct and flood out.
It has happened on my old tractor(901 Powermaster) as well as a friend of mines tractor(8n)

Not that it is 100% but just an idea.
Good luck

 

[Soundguy]

if yer flaot is rubbing the casting.. it's hinge and or pin is badly worn.. it should not rub by design..

 

[GT65]

Tractor wasn't designed for use with add on filter.Remember there is no pump. Fuel is gravity feed so anything unnecessary can only impede the flow! Also make sure the gas line runs straight as possible(leave enough clearance away from exhaust manifold so gas doesn't "Vapor Lock")from tank to sediment bowl,making sure to eliminate all "sags".
They were designed as such: 1- screen at exit of tank 3- sediment bowl
2- line straight down to sediment bowl(no sags!) 4- screen before entering carburetor.
One guy removed his inline filter and he was amazed at how much better it started. I learned this from an expert on another site and always figured if the above 4 steps WITHOUT an inline filter were good enough for Henry Ford then it was good enough for me! Good luck and please post back the result! GT65