John Deere 50 won't idle

[Mandy74]

I am hoping for some answers here. I am at a complete loss. I have bought a John Deere 50 about a month ago. When I bought it was told the carb was redone and needed to just be adjusted. So after many hours of adjusting the carb the tractor still would not idle. So sent my carb to poppin john and had it rebuilt. Got it back and still not difference the tractor will not idle. So after furter investigation found out that the distributor needed to be rebuilt. Sent that to poppin john also. Got it back after set the timing on the tractor still won"t idle. The timing on the high rpm is right at 20 the timing on the low rpm is right at 20 is that normal? So after reading the manual decided to adjust the gap at the tappets. Find out there was no gap at the tappets so adjusted that to .020 and the tractor still will not idle. I adjusted the trottle rod to 1/2 hole short. The tractor will not idle. Can you guys please offer any suggestions.
 

[NoDakInMN]

When you say "will not idle" could you be a little more precise? Does the tractor not idle down, does it come to a complete stop, does it miss or does it surge rpms? This would help in trying to figure out what is going on.

Have you checked your compression? I'm guessing there was a reason why the previous owner had the carb rebuilt and it looks as if his original diagnosis was in error.
 

[Mandy74]

The compression on both sides is right at 100 psi.

The tractor idles but every once in a while it
misfires and then after warm up it surges rpms and
it will not idle at low rpm it dies everytime.
 

[Machinery-Man]

compression is adequate...your primaries are plugged...those carbs are really hard to clean out...I've worked on them 3-4 times before getting the primaries cleaned....if one could removed the pressed in balls it would be easy...you just have a plugged carb....
 

[Mandy74]

I sent my carb off to Poppin John which is highly recommended by everyone on here. He put the carb on his tractor and it ran just perfect. Just have a hard time believing it is the carb. Thanks machinery-man for your advice.
 

[Mike M]

If it ran on a test engine then I'd try and test yours for a vacume leak.
 

[Mandy74]

Not to be stupid but any suggestions on how to check a vacuum leak. I used start fluid and sprayed around the gaskets on the carb to see if the engine rpms raise showing signs of a leak but didn't get any change in rpms.
 

[ET]

Does the idle improve if you pull the choke out a little bit?
 

[Mike M]

Well what you did would be my first try too. I seem to recall someone on here having trouble with a B and it had a burned out manifold. I think they applied air pressure or vacume to it to somehow ?
 

[Mandy74]

Would resurfacing the manifold take care of the burn out or would I need to purchase a new one? I was also thinking maybe a clogged air cleaner!!
 

[teddy52food]

I guess I would pull the manifold & see if there is leakage between the ex and intake.
 

[warnerntn.]

if you had your distributor rebuild,did you reset the timeing.also check and make sure the air-intake is not pluged up.
 

[Mandy74]

I got the timing set for full throttle right at 20 degrees past TDC. I can not get the tractor to low idle without dying to set the time at low idle. Just trying to figure out why it will not idle low without dying.
 

[turklilley]

You wrote you had timing at 20 past TDC, Set it at 20 before TDC
 

[Mandy74]

Sorry! My misprint it is set for 20 degrees before TDC. But the problem is it wont idle long enough to check low idle timing.