engine surging

[carol williamson]

I am having a problem with my Ford Jubilee. The engine continues to surge during idle or powered up. any help appreciated.

 

[old]

Most of the time when an engine does that it is caused by the carb set to lean or the carb not getting enough fuel. You of course could also have a clogged up carb. I would start by opening up the main jet a little at a time. Keep doing that till either the man jet adjustment needle will pull out of the problem goes away. If you get to the point you can pull it out then you have a clogged carb or a fuel delivery problem

 

[Jerry/MT]

Oid gives you good advice. If adjusting the carb doesn"t work, look for a screw on the governor housing. (Not all engines have this feature.) Gently screw that in only enough to prevent the governor from hunting.

 

[Geo-TH,In]

OLD,
I think if you open the jets, ccw, you will lean the carb even more.

I once turned off the gas, removed the bolt from the bottom of the carb bowl, drained the gas, used compressed air to removed the dirt from around the low speed jet, removed the jet and gave the jet a blast of air. Cleaned up my idling problems without taking the carb apart.

Try using a little choke when tractor is having a problem and if that corrects the problem, you are for sure running lean.

Hope this helps.

George

 

[old]

Geo that are 2 jets one is the idle which as you open it up more leans out but the main jet when you open it up makes it run richer.
Idle it the one close to the top of the carb just below where it bolts to the manifold and the main jet is the one that sits at a 45 degree angle and points down. Sorry Geo but I have rebuild so many carbs in the past decades that they are child's play most of the time

 

[Geo-TH,In]

OLD,
So, I'm half right, opening the idle jet leans the mixture.

My 1953 IH C has only one jet and it too is backwards, opening leans the mix.
George

 

[old]

Ya a Farmall C has only the idle adjustment on it no main jet adjustment Yep got a few of those carbs in the shop right now since they are the same as on the A and B and C. Matter of fact I am building a BA which is a mutt made from parts from both a A and a B

 

[Geo-TH,In]

Old, Why did they make the carbs with backward adjustments? What is the point? If I were guessing, might it have something to do with hand cranking.
George

 

[old]

Well in the idle circuit things sort of work backwards of how they work in the other area so it controls air flow more then fuel flow for idle or at least that is how I understand things

 

[Geo-TH,In]

I still wonder what they were thinking to build when they built them backwards. Are they still do that today on other carbs?

 

[old]

As far as I know all carbs are built that way be it on a car or a lawn mower or between

 

[Geo-TH,In]

My old lawn mowers with adjustable carbs were not reversed, turn the jets in and they get leaner, not richer. Still don't understand why the jets on some old tractor are backwards.

 

[old]

Ah but did you lawn mower have 1 or 2 adjustable jets?? If one then that would be the main jet if on the lower area. Now days a lot of lawn mower carbs have no adjustments on them but the older ones still had a idle and main jet and the idle worked the same as on a tractor. Yep did that for a living for a summer or 2