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David Bradley Walk Behind Tractor and Engine Swap

"A scythe is great for your back but very hard on your patience"
- Patrick at Far Better Farmstead     

It all started when it rained 80 inches this summer. Yes, I said 80 inches! Needless to say, I didn't get to put up much hay with my scythe and rake. I did do one good cutting, but should have got 2 or 3 and even the one cutting didn't cover the whole field. As much as I like the scythe, I started wanting a quicker way to cut a small amount of hay. 

My fantasy rig is my old 600 Ford tractor with a sickle bar, rake, and old square baler. I sold the 600 several years ago and have regretted it every since. My second fantasy was a BCS or Grillo walk behind tarctor. You can get a sickle for them and many other implements as well. Both options are out of reach of our budget right now, so that's why I call them fantasies rather than options!

As I searched around the web, I found out that Sears used to sell a walk-behind tractor called the David Bradley. It was made from 1946-1968 and you could get a large variety of implements for it, including a sickle bar mower. I started searching around and found one with a plow, snow plow, and sickle bar for a very reasonable price - a price within my budget.

My son and I drove about 150 miles to pick it up, but it was well worth it.

I fell in love with the "Rocket Man" hood!
It is an original 917.57560 "Super Power" from 1951 -1953. It even has the original engine! I had to free up the clutch on the sickle bar, but nothing other than that.

The engine is the original Briggs & Stratton model 8 (500.108022)
After cutting down about 1/2 of my cornstalks I realized the original engine was a little tired, even though it runs very smooth. I purchased a 79cc Predator engine from Harbor Freight. It is a Honda knock-off and at $79 out the door, one of the best engine deals going. The bolt pattern is exactly the same as the Briggs. It takes about 20 minutes to swap the engines. The performance improvement was very noticeable. The new engine is quieter as well.
4 engine bolts, 4 engine plate bolts, 1 fuel line, and the throttle cable are all that have to be removed

Close up of the Predator engine. It runs quiet and smooth so far.

I realized the awesome hood couldn't easily be made to fit, so I removed it. Later in the day (after finishing mowing the corn stalks) I removed the old gas tank too. It looks like a strip down but it works well. The whole set up only costs about 1/2 the price of the BCS mower (not the tractor just the attachment!)

I guess it looks like a later model now, but it works really well!
No need to worry, I kept all of the original parts and I have a dry place for the tractor and all of the parts. It would take 30 minutes or less to put it back to "original". 

Now I am looking forward to cutting a little hay. Of course I will still be raking and stacking, so if the finances work out I may end up with an old tractor/sickle/rake/baler set up but for now I am hopeful and pleased. 


  1. I have just purchased an old jari sikle mower for 20 bucks and it has an old 3 hp briggs identical to the one on youres and it needs more work than I'm willing to put into it to get it running so I was considering a harbor freight motor. Are you happy with yours has it held up well. Thanks.

  2. Yes the Harbor Freight motors are great for the money. Always shut the fuel off and let the carb empty itself to stop when you are going to store it and they give no trouble. Let that carb sit full of gas and they never seem to run right....

  3. Did you swap the pulley, or use what came with the HF motor?

  4. The stock DB pulley fit just fine. As I recall the Harbor Freight engine was bare shaft - no pulley included.


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