JD 50 idles and runs rough, revs up and down

[chas036]

My 50 ran perfect last year when I stored it away for winter. This year when I started it up, it ran terrible, spitting and sputtering and I could hardly keep running. Immediately I thought the carb had some dirt or water, so I took it off and completely cleaned all the passages with carb cleaner, blew high pressure through everything and ran wires through in all the holes. Put the carb back on the tractor , but now it would hardly start at all. When it did start, it ran worse than before to the point i could not keep it running.

I remember a problem I had like this with my Oliver 1800 and it turned out to be the condenser. I changed the condenser on the 50 and now it fired right up, but still it was "hunting" a little with revving up and down. It starts easy now, but I can't figure out what is causing the revving up and down .

My experience tells me it is carb related, but I cleaned every passage possible in that carb and even took off the side plugs and blew air through those passages.

Can someone give me some ideas where to look? Could it be other ignition problems like points or timing?

Also what would cause a condenser to fail? I bought new points and condenser last year.

 

[used red MN]

My 50 ran perfect last year when I stored it away for winter. This year when I started it up, it ran terrible, spitting and sputtering and I could hardly keep running. Immediately I thought the carb had some dirt or water, so I took it off and completely cleaned all the passages with carb cleaner, blew high pressure through everything and ran wires through in all the holes. Put the carb back on the tractor , but now it would hardly start at all. When it did start, it ran worse than before to the point i could not keep it running.

I remember a problem I had like this with my Oliver 1800 and it turned out to be the condenser. I changed the condenser on the 50 and now it fired right up, but still it was "hunting" a little with revving up and down. It starts easy now, but I can't figure out what is causing the revving up and down .

My experience tells me it is carb related, but I cleaned every passage possible in that carb and even took off the side plugs and blew air through those passages.

Can someone give me some ideas where to look? Could it be other ignition problems like points or timing?

Also what would cause a condenser to fail? I bought new points and condenser last year.

Hold the throttle lever at the carb still, if it continues to hunt.. I know it is severe punishment, but you’ll have to clean the carb again. If holding it still makes the hunting stop you have a linkage adjustment problem or a problem in the actual governor.

 

[a49deere]

Did you clean the points?

 

[chas036]

Did you clean the points?

No , I have not touched the points yet, but I have some on order.

 

[a49deere]

No , I have not touched the points yet, but I have some on order.

if they were new last year a cleaning and gap check should all you need to do to them! Like USED said, check the linkages. Sounds loke a governor or sticking linkage to me. OR the Not as clean as you thought carburetor!! Also, did you drain tank and put fresh gas in it? Check for good fuel flow?

 

[chas036]

Hold the throttle lever at the carb still, if it continues to hunt.. I know it is severe punishment, but you’ll have to clean the carb again. If holding it still makes the hunting stop you have a linkage adjustment problem or a problem in the actual governor.

I just started it up again and held the throttle steady and it did not "hunt" . It backfired a few times, but it did not rev up and down like before.

I assume this is the governor now, and what is the my options?

Are these hard to rebuild and what goes bad inside?

 

[a49deere]

Make sure you pivot points are freely moving and check for a cotter pin that may be rubbing on your throttle linkage. Check your timing too!

 

[chas036]

Make sure you pivot points are freely moving and check for a cotter pin that may be rubbing on your throttle linkage. Check your timing too!

I have not checked the timing . Tomorrow I plan of taking off the carb again and cleaning another time. I also will rest the points and check the timing.

What do i have to look for with respect to the throttle linkage and the governor linkage?

 

[a49deere]

It's a tight spot were throttle linkage attaches to carb. cotter pin at this spot could be interfering with throttle. governor shaft out of top of governor should move freely with no binding. Make sure the shaft at top of governor is lubricated along with pivot points on linkage. Check cotter pins on end of governor spring and governor arm are for interference.

 

[PJH]

I have not checked the timing . Tomorrow I plan of taking off the carb again and cleaning another time. I also will rest the points and check the timing.

What do i have to look for with respect to the throttle linkage and the governor linkage?

When you attach the "governor to carb" rod to the "governor arm" there should be a 1/2 hole misfit. I can never remember which direction is the misfit, and my manuals are out in the shop. Someone here will know.

 

[Mark-Ia]

If you didn't remove those little balls that plug the passages, you didn't get the carb clean.

 

[744k]

Should be a 1/2 hole short

 

[chas036]

If you didn't remove those little balls that plug the passages, you didn't get the carb clean.

Today I started the tractor and it fired up but I could hardly keep it running without playing with the choke. Finally after a few minutes and the tractor warming up, and continual playing with the choke , I finally got it to run, but with revving up and down. Now I am sure the problem is the carb

You mentioned removing the small brass balls. I have never done that. What is the procedure, and can you get replacements? Is there a Youtube video showing how to do that?

 

[chas036]

If you didn't remove those little balls that plug the passages, you didn't get the carb clean.

I just found a video with a young girl cleaning that carb and she mentioned about those brass balls and you have to drill into the carb on each side to get them out and only if you have a lot of experience doing it. So this is nothing I want to try.

Is there any other way to clean those passages.?

 

[a49deere]

I just found a video with a young girl cleaning that carb and she mentioned about those brass balls and you have to drill into the carb on each side to get them out and only if you have a lot of experience doing it. So this is nothing I want to try.

Is there any other way to clean those passages.?

Yes, send it out to a reputable carb shop!

 

[matthies]

All the balls I seen are steel, brass plugs yes. I have been lucky enough to soak the bad carbs in vinegar to clean the passages, never failed me yet. Don't soak it overnight, just keep an eye on it for a few hours and when you see a lot of bubbles pull out rinse in a hot water/baking soda mix then blow dry then soak in parts solvent to keep from flash rusting.

 

[chas036]

All the balls I seen are steel, brass plugs yes. I have been lucky enough to soak the bad carbs in vinegar to clean the passages, never failed me yet. Don't soak it overnight, just keep an eye on it for a few hours and when you see a lot of bubbles pull out rinse in a hot water/baking soda mix then blow dry then soak in parts solvent to keep from flash rusting.

Rather than using vinegar, could I just soak the whole carb in brake/parts cleaner overnight? That would eliminate the possible rusting.

 

[55 50 Ron]

even took off the side plugs

I think there are holes accessible through the side plugs that need cleaning with certain precise size drill bits.

 

[matthies]

Rather than using vinegar, could I just soak the whole carb in brake/parts cleaner overnight? That would eliminate the possible rusting.

The vinegar gets rid of the rust, parts cleaner doesn't touch the rust.

 

[shaun wallace]

Was the brass nozzle pulled?