Mystery Engine Identified And Revived

| February/March 1988

  • 2 HP Termatt and Monahan engine
    2 HP Termatt and Monahan engine

  • 2 HP Termatt and Monahan engine

20601 Old State Road Haubstadt, Indiana 47639

It was a pleasant experience a while back to acquire a gas engine of unknown brand through a good friend, but it came with problems. The fuel mixer was missing, but it was located among other things near the engine. It had no identification tag nor any sign of a decal or other decoration even though the red color was quite evident. On the third time through the American Gas Engines book, a similar engine was finally spotted on the bottom of page 509. Another similar engine was found on page 56, volume 7 of Alan King's gas engine ads. It turned out to be a 2? HP Termatt and Monahan engine made at Oshkosh, Wisconsin in about 1915.

Being satisfied with identity, the restoration process began. Since no other information was found, the only references that I had were the two Mentioned above. The engine was disassembled and sent to the local metal laundry to remove paint, rust and grease. The cylinder was rebored and sleeved since the piston pin had come loose and had worn two grooves down the cylinder wall. The rod had been broken behind the piston pin bushing and welded crooked. A new bushing was made and bored to line up with the rod. A new piston pin was made and refitted because the holes in the piston were worn too. Rings l/64th inch wider were ordered and the piston was turned to accept them.

The gas tank was missing, but with some adaptation, a tank of unknown origin was made to fit.

The timing gear had a cam on each side. One operates the exhaust valve mechanism and the other operates the magneto mechanism which was missing. That had to be made. The magneto bracket had been sawed off and bored for a spark plug. By sheer luck, a bracket was found that fit, but it was for a smaller magneto so it had to be modified to accept the right size.

Since the cast iron crank guard was missing, one was made out of heavy sheet metal and a bead was rolled along each side for decoration and stiffness. Decals with a likeness to those in the pictures were made by using pressure sensitive paper, black ink, transfer letters and book tape. Apparently there was no striping or other decoration on the engine so after a coat or two of primer and some body filler, two coats of bright red paint were applied. The cart was made from oak and fitted with used wheels.


Gas Engine Magazine A_M 16Gas Engine Magazine is your best source for tractor and stationary gas engine information.  Subscribe and connect with more than 23,000 other gas engine collectors and build your knowledge, share your passion and search for parts, in the publication written by and for gas engine enthusiasts! Gas Engine Magazine brings you: restoration stories, company histories, and technical advice. Plus our Flywheel Forum column helps answer your engine inquiries!

Be sure to take advantage of the Square Deal Subscription Program.

  • No Missed Issues.

  • No Renewal Notices.

  • No Additional Cost.

The Square Deal Subscription Program is designed as a paperless transaction with automatic renewals at a preferred low rate.   With advanced electronic notification, a 100% satisfaction guarantee and an easy opt-out plan, the Square Deal Subscription Program is the best value, risk free, eco-friendliest way to subscribe.

Facebook YouTube