More SC questions

[messy gearhead]

Are vacuum leaks or rusted out manifolds common on the SC tractors? Mine only runs with the choke full on and I'm wondering if I could have a leak somewhere. The carb was a rebuild, looks spotless inside. Spark is good, plugs are new. I'm starting to get really frustrated with what I thought was going to be an easy project taking up way too much of my time.

 

[TripleRange]

The only way you get an easy project is if you think it's going to be extremely difficult to start off with. ;-) I'd check the flow to the Carb before anything else. Then your right....start checking for manifold leaks or gasket leaks behind the carb.

 

[Patsdeere]

SCs were known to rust through between the intake tubes and the exhaust tubes. Try searching past posts for manifold problems and you will find some solutions.

 

[Anonymous-0]

Could the carburetor float be set too low and not allowing enough fuel into the carburetor bowl? Is there good vacuum when you place your hand over the carburetor air intake?

 

[lk]

I have an SC and it takes mine a long long time to warm up in the colder weather. In the summer it does not need a choke long but the winter it runs a long time but after a while it will warm up. Mine is about a 40 or 41 and I am not sure what it has to help it warm up at that age.

 

[Rick Z]

Quick test for Vacuum leak on intakes or carb base.Put a rpm tach on engine.Fill a spray bottle with gas.With engine running at the lowest possible idle speed spray gas on suspected leaky areas on intakes and carb base.An increase in RPMs will indicate that a leak is present as gas is pulled into the intake by vacuum from the leak.
Rick Z.

 

[waltham41]

My 47 SC had badly deterorated manifold gaskets and the manifold had rusted through on the inside.

The previous owner had reversed the choke so it was choked when running.

I had the manifold fixed and put new gaskets on it, and had a heck of a time figuring out why it would run on full choke and die when the choke was off. Changed the choke around and all was good.

 

[PaulFH]

What exactly are the symptoms when an SC is suffering from a burned through manifold?

I've got a 49 that has been defying me for a long time. I have a good mag, good plugs, good compression, a good carb, and new head and manifold gaskets. but it runs unevenly and has barely any power. It doesn't need the choke out to run but it only likes a very rich mixture; so rich that it fouls the plugs. I just rechecked the timing again and it seems to be right on.

I'm running out of things to look for.