Updating '47 Cub

Tue Mar 12, 2013 8:45 am

I am about to begin restoring a '47 Cub. It's all original right now, but I'd like to improve on some things while I'm tinkering.

I believe all the internals are OK. And right now I'm just working on the engine. My main two points of focus are the fuel system and the electrical system. I want to be able to use this tractor for some chores, so I want it to crank easy and run smooth.

What are the recommendations as far as going to a 12V system? Can I help the ignition system any? The tractor is going to have to be completely rewired no matter what system I go with.

What about the carburator, anything to help it? I'm planning on putting a cutoff valve below the sediment bowl.

Just looking for any advice on where I should be aiming to go before I get started.

Re: Updating '47 Cub

Tue Mar 12, 2013 9:09 am

As to going to 12volts, that is a personal decision. It will crank over faster, but if the 6 volt system is maintained properly it will not start any better. If the generator and battery or bad it is cheaper to go to 12 volts, if they are good, again, it is a matter of personal choice. Cleaning/rebuilding the carburetor as well as cleaning any rust from the fuel tank are good. Get an owners manual and lubricate everything per it's instructions, not forgetting the clutch throw out bearing, and the fan.

Re: Updating '47 Cub

Tue Mar 12, 2013 10:44 am

There isn't much of anything you can do to a Cub to greatly improve it. Converting to 12 volt system will not make the tractor run any smoother or better.

If the generator and regulator/cut out condition is unknown, you could take to repair shop and have tested. As John pointed out, conversion to 12 volt alternator will be less expensive or of equal cost to repairing the 6 volt system.

My opinion. If I were going to completely rewire the tractor I would install a 12 volt single wire alternator. Wiring is straight forward.

I removed the sediment bowl, installed a ball type valve and inline fuel filter. Just push or pull the lever to open or close the valve.

Re: Updating '47 Cub

Tue Mar 12, 2013 7:20 pm


There are a couple things you can do to update your '47. But ... really it is simply just good maintenance. The following links are a couple projects I did to improve/replace degraded/missing parts.

1. How To Upgrade A Cub Fuel System
2. How To Build A Replacement Battery Cable

Converting to 12 volt is a waste of time unless of course you were missing the generator, regulator etc., and it would be cheaper to get an alternator. However if you 6v is working - clean it up. Start with the battery connections - make sure all connections are clean and bright then do the same with the grounds etc., they need to be clean and bright metal .. as well as all terminal connections. Also check all of your cables for corrosion or breaks in the insulation which could cause internal corrosion and lead to degradation of the circuit. If the cabling is degraded, replace them. A properly maintained 6v system will provide all the starting insurance that you need. I use my Cub all the time and it is 6v and starts nicely even in -30C and below weather. Sometimes my 12v stuff won't start ... course then it boils down to CCA of the battery.

Same with the fuel system. There are a few things you can do to the fuel system to make it work better but then again most of it really is maintenance. Clean your tank, the fuels sediment bowl, fuel line and carb is clean with no dirt, crud or other foreign objects in it. Ensure that the screens are present and clean. Bring it back to IH Specs and if you want to make it easier add a ball valve instead of the T-shaped shut-off valve.

A good tuneup as well as checking the valve lash will do wonders and of course SeaFoam in the gas and oil will be a good idea.