Suddenly rough running JD model 40

Dean Wilson · Apr 23, 2015

I have a '54 model 40 JD. All the electronics are new including rebuilt distributor. The carburetor was just rebuilt by robert's, and all gas lines are clean with new filters.
It run it for about 2 hours and all was perfect. Then it just started running very rough, It will run great for a few seconds or even a minute, then it misses very bad, with no consistency.
The ignition checks out fine, good spark to plugs. I think it has to be carburetion. Can a sticky needle and seat or float be the cause? This is hard to figure especially after spending $590.00 on rebuilding
a DSX 245. Any ideas would be appreciated.

DeltaRed · Apr 23, 2015

Bad condencer

Carlyle hoffman · Apr 23, 2015

Take the CONDENSER back wear you got it and go some wear else and get 2 more, one might work.

gene bender · Apr 23, 2015

So why did you overhaul the dist wasnt it working. Seems like too often people start putting newparts on when probably didnt need them did it miss before or has this just started.

RBoots · Apr 23, 2015

You're not kidding! The new ones you get now are junk! I have replaces more condensors in the last few years than I can remember. Never had problems with the older ones, sometimes replace the bad "new" ones with an old one from my stash.

Ross

60 acre hillside · Apr 23, 2015

Jew about valve clearances?

buickanddeere · Apr 23, 2015

(quoted from post at 18:35:22 04/23/15) I have a '54 model 40 JD. All the electronics are new including rebuilt distributor. The carburetor was just rebuilt by robert's, and all gas lines are clean with new filters.
It run it for about 2 hours and all was perfect. Then it just started running very rough, It will run great for a few seconds or even a minute, then it misses very bad, with no consistency.
The ignition checks out fine, good spark to plugs. I think it has to be carburetion. Can a sticky needle and seat or float be the cause? This is hard to figure especially after spending $590.00 on rebuilding
a DSX 245. Any ideas would be appreciated.

Keep the coolant temp above 195F. Use solid core wires and Autolite 437 plugs. Or spiral wound wires and a pertronix points replacement with the 437 plugs.

RLA · Apr 23, 2015

By all means try another condenser 1st~~~~~~~~~

robgIN · Apr 23, 2015

amen , at least 2.....

James Howell · Apr 23, 2015

Agree with others on replacing the condenser first.

We have a 51MT that will act as if running out of gas and quit running.

Other times it will quit running as if the ignition is turned off.

As others have mentioned, not all new condensers are good; have experienced that disappointment at least twice.

Sounds like the rest of your electrical system is in very good condition.

Hope this helps.

Dean Wilson · Apr 23, 2015

The distributor needed the bushings replaced. The shaft wiggled all over the place.

JRSutton · Apr 24, 2015

Not disagreeing with others on the condensor, but personally - were it ran good for a while, I'd first suspect junk in the carb.

Cleaning a carb is free and easy enough. I'd just rip it apart and blast it all out.

Condensors aren't particularly expensive or tough to swap either - so it's kinda 6 of one half dozen of the other - but to me, I'd just lean more towards the carb.

NoNewParts · Apr 24, 2015

while New electrical parts are always suspect today....
Debris or water in the fuel will do it too.
A touchy needle in the carb will give those exact symptoms.
I have one Farmall with a very touchy walbro carb on it.
Needle sticks open just a bit sometimes, and I hear the change in engine sound first, then missing and smoking if I don't get after it.

needle sticking shut....quits or pulling the carb bowl drain and getting nothing or a trickle

needle/float hanging open....turn the gas off...if the engine smooths out for a few seconds just before it stalls...bowl was overfull.

Suddenly rough running JD model 40

Dean Wilson

New User

DeltaRed

Well-known Member

Carlyle hoffman

Member

gene bender

Well-known Member

RBoots

Well-known Member

60 acre hillside

Member

buickanddeere

Well-known Member

RLA

Well-known Member

robgIN

Member

James Howell

Well-known Member

Dean Wilson

New User

JRSutton

Well-known Member

NoNewParts

Member

Similar threads