The Dale C. Maley Family Web Site

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Cleaning Waterloo Hit n miss Engine Gas Tank

Sep 2021

My consultant on my 1923 Waterloo hit n miss engine told me the first day I bought it that I should clean the gas tank.

I resisted doing this because of the difficulty of cleaning the gas tank. You have to lift the ~350 lb engine off the cart, then flip it over, and then remove the following:

-bracket that hold assembly together

-fuel tank

-fuel tank to plate #1 gasket

-plate #1

-Plate #2

-plate #1 to #2 gasket

-plate #3 with oil bowl

-Plate #3 to main engine gasket

I made this illustration to show the assembly:

My Waterloo Engine

My serial number of my Waterloo engine is 253069 which corresponds to a 1923 manufacturing date. If I remember right, John Deere bought the Waterloo company to get their very popular Waterloo Boy tractor. JD kept on making the Waterloo hit n  miss engine and made no signifiicant design changes.  Many replacement parts are made for the John Deere 1.5 Hp engine, which fit fine on the older Waterloo models.

Gasket Set

Last winter I ordered a gasket set for about $50 from ZKStuff on Ebay.


I drained the water, then the gas. I removed the pipe cap end cap to drain the oil, but not much came out. I forgot there is another drain plug below the governor side plate. I figured I did not get all the oil out, and would leak some when I flipped the engine over to work on the gas tank.

Lifting Engine from Cart

I left a chunk of 4x4 beam in my attic the last time I pulled the engine from the cart. I attached the hand winch to it. Then attached the chain to the engine and removed the 4 bolt nuts.

I had to temporarily remove the hook from my chain, so the chain could be routed between the 1/4" copper fuel line and the block, then I put the hook back on.

I had kept the 2 wood pieces to set the engine on, so it does not sit on the gas tank, so I lowered the engine onto the 2 wood pieces and bolted them on.

I slid the engine on the 2 wood pieces over to my lane of our garage, so as to not disturb my wife's lane in the garage.

I was able to flip the engine over onto it's bottom by hand. It was safe to do this. Then the oil started to drain out onto the floor. Had to get some Oil-dri to soak up the oil from Addis auto parts.

Removing Bracket Bolts

I was able to get these loose ok using my ratchet and a wrench. I was nervous the 98 year bolts might break or strip, but they were ok. One bolt had no nut, this is the one close to the governor side panel. It just threads into the main cast iron block. I removed the bracket.

Removal of fuel Tank

I carefully drove a straight screwdriver in the side gap and got the tank off. WOW, there was a pile of rust and debris on the next plate, and the tank was filthy with debris!!

Removal of next plate

Another plate to remove

This engine has another plate with the oil cup or bowl attached it it. There is about 3/8" thick layer of sludge on bottom of oil gallery!

Cleaning of fuel tank

I did 3 rounds of oven cleaner first. Then I took the Dremel with a wire brush attachment and cleaned the top gasket surface, used a wide chisel first to remove gasket remnants.

I then used drum sander on drill press with 220 grit to clean the inside walls.

Then the round bottom inflatable sanding drum to clean the bottom.

I noticed the tank has been repaired before, with copper plate welded to bottom of steel pan. You can also see the weld on the outside of the tank.

The problem with steel tanks is that water condenses in the tank, sinks to the bottom below the gas, and rusts out the tank.

Oven Cleaner

I tried Oven cleaner from dave's supermarket in fairbury. I'm not sure it really did any good since the problem was more of rust than of baked on carbon.

Naval Jelly from Ace Hardware

Naval Jelly applied to gas tank side of steel plate

Before and After Photos of top of fuel tank and tank itself

Making one gasket

Torquing up a sandwich of 3 Cork Gaskets

With 3 layers of cork gasket, I was worried about relaxation after initial torquing of the bolts. I tightened about 3 times, then let it set for 30 minutes, then tightened them in sequence one last time.

Engine all Re-Assembled

Firing up the engine after repairs completed

When the fuel system is dry, it usually takes 5 or 6 attempts to get the motor going, probably due to slowly filling the 1/4" copper fuel line from the tank to the atomization jet.  She ran good after I got it started.

You can use this link to watch the engine running after the repairs.

Closing Thoughts on This Project

The job turned out not to be as difficult as I expected. The 98 year old bolts holding the main clamping bracket all came out ok.  It took longer to clean the parts than dis-assembly or re-assembly did, as is normal when rebuilding an engine.  I was also able to flip the engine over on the temporary wood pieces by hand safely, which I was worried about.

Putting engine away for Winter of 2021/2022

Engine ran for 2 hours fine !!!!!!  Still did not run clear out of fuel, was acting like it was getting low (taking multiple attempts to fire).  I added some Sea Foam to the remaining gasoline to see if that helps with preventing rust in the tank, plus keep the fuel good.  Checked and no obvious leaks of fuel or oil from my clean the tank repair.