"Project Bantam" - First Ride

Its been a long year.  Patience and skills have been tested along the way.  Gumption levels both plummeted and rose to new heights in the past few weeks.  Quality was balanced between practicality and schedule.  Stewardship overall was the name of the overhaul.  My hope was to have the Bantam 5000 available for my son to enjoy the same way I enjoyed it, and will continue to enjoy it.

The last new part to be installed was a new plug.  The original was the culprit responsible for hard starting.  A quick trip to the hardware store provided sweet and immediate rectification.

The float bowl still leaks, I'm told this is an inherent issue.  I haven't given up trying to make it correct just yet.  The fuel shutoff is a necessity.

Here we have a slideshow of the entire process as it arrived to our workshop, and finally completed to a level where it moves under its own power.  Sit back and relax, it takes a while to go through all 50 photos.

And finally the triumphant First Drive together.

There will be more reports on further detail work and fiddling...

"Project Bantam" - Fan Shroud

The Briggs and Stratton 14-FB fan shroud was completely rotted through on the bottom.  Even back in the 1980's it had a patch pop-riveted to the bottom.  This repair stretched my bodywork skills (or lack thereof).

The electrolytic de-rusting process got the part down to what was left of the base metal.  It was pretty ugly.

The patch was made of comparable gauge material with the worse of the rusted sheet metal cut away.  The back plate was used to hold the correct diameter and curve of the fan shroud.  I kept it bolted in place while the patch was tacked into place using oxy-acetylene and a brazing rod.  The brazing rod wicked pleasantly into the new patch material and surprising well onto the original part.

Here's the finished part after all the brazing was completed.   Brazing was certainly a much easier option than straight welding, but still it resulted in some distortion of the sheet metal.  I ground off the excess material and hammered any distorted surfaces flat.  The Bondo stage and glazing putty is always the hardest for me.  The Bondo sets up too fast, so I have to work in small batches.  When it is sanded it always sticks to the sand paper.  The glazing putty is easier to work with since it dries harder, but only covers small areas at a time.  Altogether its not too bad considering what I had to start with.  Its by no means perfect, but I did it myself, which is what counts for me.  Its only the bottom, which is obscured when the engine is installed in the tractor anyway.  You can't see straight into the shroud for this reason as well, so imperfections will be difficult to see.

The current plan for the exhaust and muffler is to use the original.  It went through the de-rusting electrolyte tank and actually came out without any holes in it.  The EMT conduit fitting is still serviceable into the exhaust manifold elbow, so instead of risking cracking the block, I'll just keep it.  I can always make a new exhaust later if I want.  I have no idea what the stock Bantam exhaust was like.  My father fashioned the current muffler from a spent propane torch tank.  It slings neatly under the floor board and attaches to the bolt holding the transmission in place.  The nice thing about this exhaust arrangement is that it keeps the heat away from the driver.

"Project Bantam" - Engine fires off

I stayed up a little later than usual to try to get some more work done on the 14FB engine. The axial float was easily obtained by making a slightly thicker gasket. The backing plate for the fan shroud hadn't been painted, so I did that before going to bed.

The rest of the tinwork went on easily and looks sharp.

The head was torqued down and carb mounted. All that was left was to set the ignition timing and points. The Magnematic is so simple to set. Gap the points, use a test lamp to watch for the points just opening. Then set the coil to point at the arrow on number 14.

I bolted the engine to a plank for stability. Shooting some ether, and pulling the cord yielded a satisfying BANG! I'm grinning.

The fan shroud still needs some structural repair.... The next task.

"Project Bantam" - Arts and Crafts

I've finally amassed all the parts required for the Briggs&Stratton 14FB engine overhaul.  The main bearings look good, and the piston ring gaps are within spec using new standard size rings.  One of the exhaust valve keepers was rattling around in the tappet chamber when I opened the tappet cover last month.  The exhaust valve seat was rather rusted and required significant lapping to get down to good metal.  A quick grind on the valve stems put it back within gap specification.

exhaust = 0.015"

intake = 0.008"

The gudgeon pin is still tight and the piston looks good as well.  It can be put back in with the new standard size rings.

I went with a two-tone paint job on the block.  The fins were rather rusted, so I wanted to make sure they got painted and stayed painted.  So they got a 1200'F rated exhaust paint in silver.  The crankcase got a 500'F rated engine paint in black.  The exhaust elbow was rusted fast, but the threaded adapter to the exhaust pipe still had good threads, so that's staying.  I just need to obtain a new mating nut and olive for the exhaust.  It looks like an electrical fitting.

I had my son help with the arts and crafts.  Making measurements and cutting gaskets is a tedious task, but still enjoyable.  I started with some relatively thick gasket material for the tappet cover, point cover, and oil pan.  The bearing housings require some adjustment based on axial float of the crankshaft.  I made them out of thin material as templates.  I can go back and duplicate these easily when I get the crank set in, if the float needs increased to meet spec in the manual.

On closer inspection there are marks on the inside of the timing gears.  It looks like someone has had this engine apart before, since the cam gear has a awl scratch on it pointing to the correct place between the timing teeth.  The manual says to set the timing based on the outside of the gears, which is presently obstructed by the main bearing.  Timing will have to be set by the inside viewing through the bottom of the crankcase.

"Project Bantam" - Fuel Tank

The steering shaft and new gear went on without any trouble.  The ends of the shaft were a little mushroomed, but nothing a quick turn on the lathe couldn't fix.

The fuel tank was new from Mr. Shaffer.  I decided to powder coat it for extra durability. It came out looking great for a part that is not seen.  The original sediment bowl was lost, so a new Briggs-Stratton model 690612 was easily obtained.

The support straps were made from some spare stainless that I had lying about in the scrap bin.  To keep the neck from banging up the hole in the hood, I stripped some wire and used the insulation to protect the hole, by splitting it with a razor blade and fit that to the edge of the hole.  Using some silicone lubricant, the neck slid nicely into the hole.  Some inner tube rubber made a nice cushion for the fuel tank.

It looks more crooked in the picture than it actually is, because of the odd angle I had to take the photograph from.  (Don't mind my finger in the photo.)  Notice the nuts holding on the bolts onto the hood, since the original holes no longer had sufficient threads to hold the bolts to my satisfaction.

The body is looking rather finished at this point.  Considering how poor the tractor looked when it rolled into the workshop, its a ten-footer overall.  Not a show winner, but a restoration staying within a reasonable budget.

Hopefully the next post will involve some progress with the engine.

"Project Bantam" - assembly mockup

Since most of the sub assemblies were already prepared (except for the engine). I was able to set the pieces together to make sure everything fit right.  In retrospect, this should have been done before I painted.  I would not have thought that there would be a problem with the fit of the new fenders.  The build tolerances are not the most precise, so it should not have surprised me that there was a problem.

  

From the picture you can see that the right fender does not fit down against the running board.  Its too late now, a spacer will have to be fabricated.

The original input shaft stud mount bearing was completely shot.  This consequently wore down the shaft, which had to be repaired with welding in more material, and then machined down again.  Otherwise, the input shaft fit right back in place.

Otherwise parts fit back in position as they were originally. Its starting to look more like just a collection of parts now.

"Project Bantam" - Orange

All the de-rusting, blasting, bodyfiller, and sanding has culminated in this weekend of painting.  A six-pack of Kubota Orange tractor/implement paint has transformed the pile of tractor parts.  Only the hood has too many imperfections for my liking.  It will have to be sanded down again and re-sprayed.  They body looks good enough, as do the grill and fenders.

  

The basketball hoop in the driveway served as a great location to paint the body.

The only part which hasn't been painted now, is the engine.  I still need to come up with a plan for the exhaust and muffler.

 

The front wheel assembly went back together easily. The new design for the wheel bearings should be much more reliable.  I can't wait to mount the rear wheels and pillowblock bearings I bought to replace the rear axle bushings (which looked rather sorry and worn).

For now the paint must dry and I can drink a beer with a sense of accomplishment.  After getting everything painted, I'll need to purchase a set of new fasteners.  Tractor Supply sells fasteners by weight, so I'll have to compile a shopping list soon.

"Project Bantam" - I was rebuilding a tractor wasn't I?

There have been delays in the progress.  I had to use someone else's sand blaster to strip the frame, since my compressor couldn't muster the pressure needed.  It all turned out rather well.  I had to fix some structural items and prime it immediately to prevent surface rust.  It turned out rather well, but still needs some more structural work before continuing the body work.

Just to remember how bad it was, it sat under this tree for YEARS.

The structural welding is done, and the body work is complete.

The next step is to start applying the final paint coats.  I'm going with the Kubota color in enamel.  Its not as pleasing to me as the Allis Chalmers orange, but the Kubota color is closer to the original as far as I can see.  Reassembly of the body is just around the corner.

In other news, the front tire went on the rim easily.  I also had to re-design the front wheel bearings.  I used sealed bearings in the center, a set of spacers, and some flanged bearings on the outside with another set of spacers.  To keep the spacers from falling out, the whole assembly will need to be arranged with a dummy-shaft, and then the axle bolt inserted once placed in the steering yolk.

(Poor little guy just woke up from his nap)

"Project Bantam" - Tire Mounting

It turned out the best place to obtain the Carlisle Power Trac rear tires was Walmart.  They had them the following day, and there were no shipping charges.

The rims were de-rusted and the rust holes were filled in with bondo and glazing putty.  The top coat was a matte finish to hide my poor bodywork skills on curved surfaces.

 

The tires went on easily with new inner tubes.  The 4.8" width is marginal compared to the original 5.0".  They really do look good though.

"Project Bantam" - Carb corrosion

While this doesn't look too bad on the outside, inside lurks horrible corrosion to haunt your dreams.

Finally managing to coax the carb apart exposes the full horror of how much corrosion can actually enter a carburetor.  The float was split from freezing, and also made concave in one area due to the pressure of ice under it.

I've never met a float that I couldn't solder back together, and this was no exception.  I can solder anything.  It took a few hours of cleaning, careful straightening, and reforming.  The difficulty was in the brittle nature of the inner side walls.  They had to be tinned from inside and out.  I don't know if it will hold up in the long term, but its water tight now.

The final product looks fairly good. I spent an entire afternoon with the top of the carburetor in the lathe truing up the mating surfaces of the flanges.  The screw tabs were bent from over-tightening, and prevented the whole assembly from fitting together correctly without any air leakage.

It will be seen whether the corrosion of the thread holding the main jet (which prevented its removal) is problematic.  The only issue now is to set the float level and find a packing nut for the main jet adjustment needle.

On a side note, the main jet of the carb had to be drilled out to fit the new one I bought in a Stens 520-049 rebuild kit (original B-S kit # 394693).  The Stens needle valve kit 525-246 (original B-S kit # 99525) will have to wait until I can clean the tapped hole in the body with a 5/16-32 bottoming tap (once I get one).

"Project Bantam" - brass ring gear reproduction

Bob Weaver in Shelby, Ohio had a batch of reproduction brass ring gears made.  During Bob's own restoration he needed one as well, and I was fortunate enough to obtain the second-to-the-last one he had made.  The Weaver family were very pleasant folks and I enjoyed doing business with them.  The gear looks like good quality American workmanship.  That kind of workmanship is worth it, and it didn't come cheap.

"Project Bantam" - magnamatic ignition

I came across this article in Gas Engine Magazine, and I'm certainly glad I did.
http://www.gasenginemagazine.com/gas-engines/cheap-fix.aspx
The author showed how to fit a common B&S coil to the Magnamatic Ignition on this model FB engine. The concept is simple. Remove enough material from the core to make it fit under the flywheel. And it is tight.

Original Coil

After some careful hacksaw work and filing, and I think it turned out rather well. I did not use a hoseclamp like the fellow in the article. I fashioned two spring clips to emulate the original ones. I made them VERY tight, and also put a screw on one side to positively locate the coil along the shaft axis, as an added measure to make sure it doesn't wander around due to vibrations.

Modified Coil

Modified Coil and Core assembly