Grasser Marine Engine – Part 2 of 2

By Staff
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Dave Irey's circa-1907 Grasser marine engine.
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Fitting new gaskets to the crankcase.
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The nearly completed frame with engine base/crankshaft and clutch assembly set in place.
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Straightening a section of brass pipe using a vice and “C”-shaped block for support.
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The Grasser marine engine’s brass parts laid out for inventory.
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Ignition timer parts. The arrow points to the new contact that had to be made.
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Vintage buzz box found at a flea market. The original condenser cartridge had to be replaced.
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Automotive distributor condenser was used in place of original cartridge condenser in buzz box.
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The Grasser’s Lunkenheimer mixer.
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The gas tank and mountings. The tank is from a 1950s lawnmower.
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The Grasser marine’s cone clutch.
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The crankshaft, clutch and clutch lever on the wooden frame.
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Getting ready for the first fire using a 1917 1 hp Alamo as a starter engine.

This is the second in a two-part series on Dave Irey’s restoration of a Grasser marine engine. Read Part 1 for the first part of the restoration.

Circa-1907 Grasser Marine

Manufacturer: Grasser Motor Co., Toledo, OH
Serial no.: None marked on engine
Horsepower: 2-1/2-3 hp (est.)
Bore & stroke: 3-1/16 in x 3-1/4 in
Flywheel dia.: 12 in x 2-5/8 in
Ignition: Spark plug w/battery and buzz coil
Governing: Throttle

With the piston, connecting rod and bearings taken care of, it was gasket cutting and assembly time. I purchased a big sheet of 1/32-inch-thick gasket paper at my local auto parts store and cut new gaskets for the crankcase. I also cut out the gasket for the exhaust flange, using exhaust gasket paper.

The rest of the engine connections are pipe thread fittings. I started the reassembly by assembling the piston, wrist pin and connecting rod. New rings went on the new piston and then I installed this assembly into the cylinder, followed by the crankshaft and main bearings. The connecting rod cap with shims was installed and the rod bolts torqued to 45ft/lb. The bottom crankcase cover was then bolted on with the new gaskets, as shown in Figure 1. The crankcase cover doubles as the mount for bolting the engine into a boat frame. As it wasn’t going into a boat, I would have to make a cart.


As I got it, the engine was mounted on a 2 x 8 wood frame. It was cracked, kind of rotten on the bottom edges and generally scruffy. I decided to make a new one from fresh 2 x 12 lumber, with two small 3-inch wheels from an old platform scale on the flywheel end so as to make it easier to move around. The new frame/cart is 33 inches long, 10-3/4 inches wide and 11 inches tall. A long diagonal cut was made across the back of the frame much like the original so the clutch can be clearly seen. To move it around, I made a 5/8-inch-round steel handle and attached it to the back end. It telescopes out of sight into the wooden frame. I also had to make a new pivot for the clutch handle. Figure 2 shows the nearly completed wooden frame.


One of the neat things about marine engines is that they have lots of brass parts. This one has a brass Lunkenheimer fuel mixer, a Tuttle-style timer and a water pump with lots of brass fittings, over 20 pieces in all. All the brass parts on the engine looked very good. Only one piece of pipe was bent and I decided to try and straighten it. To do this, I used a piece of 1-inch-square steel with a “C” cut into one side of it. I then put pipe bushings with hex threads on each end of the pipe. I clamped this into a bench vise to use as a press (see Figure 3) and tightened the vise. The pipe straightened out nicely.

The water pump is a displacement piston-type with two check valves. It was probably made by Lunkenheimer, as well. The pump looked good and was not worn out, so I decided to leave it as it was. Figure 4 shows all the brass parts.

Timer and ignition

As stated earlier, this 2-cycle engine uses a battery and buzz coil for ignition. Originally, it was probably a wooden box coil much like a Model T Ford uses. An eccentric fixed to the crankshaft works a brass connecting rod that strokes the water pump and also the ignition timer. The rod has a contact on the upper end that rubs on the timer itself to trip the ignition. The original contact was lost and someone had put a rusty bolt in its place, so I made a new contact from brass in my lathe. As I had nothing to work from, l had to imagine what the original part would have looked like. In my spring collection I found a spring about the right size and shape to work for the spring tension in the final assembly. The arrow in Figure 5 points to the new part, with all the other timer parts also shown. This type of timer is sometimes called a “Tuttle timer” after the type developed by Tuttle Motor Co. for its marine engines.

At a flea market, I found a neat-looking wooden box buzz coil called “The Cartridge Coil,” made by the Chicago Coil Co., Chicago, Illinois. In testing it did not work. I removed the back end cover and out came two wooden boxes (Figure 6) marked “Secondary Cartridge” and “Condenser Cartridge.” The decals on the cartridges are dated May 1909. Apparently, this coil was made to be serviced with separate replacement parts.

I cleaned up all of the electrical connections and reassembled it. It actually worked, however there was way too much arcing across the buzz points and a test trial on a known good-running engine revealed a weak spark. Further testing revealed a weak condenser. I substituted an automotive distributor condenser for the wooden cartridge and the spark was great, the arcing across the points normal. To keep it looking original, I made a wooden box like the condenser cartridge out of solid wood, and on the band saw cut out a place for the modern condenser to fit in, with the wires coming out of one end as shown in Figure 7. I now have a really neat-looking old coil that works great.

Fuel system

The engine as found had no fuel tank or fuel lines, so I decided to use an old lawn mower gas tank and make a mount from 11-gauge flat steel and bolt it onto the engine cylinder at the exhaust flange. This is an oval flange like on an automobile exhaust, and it won’t get real hot as it’s bolted onto the cooling jacket. Two 3/8-inch x 16 UNC bolts hold it on. The mount is made up of six pieces of 11-gauge steel shaped and welded together. The fuel tank is from a 1950s lawn mower. It was dirty inside so I cleaned it out using a small, square-linked chain and hot, soapy water. After several thorough shakings with fresh soap and water it cleaned up, rust free and ready to use.

The engine uses a brass Lunkenheimer mixer (Figure 8). Inside, the mixer has a throttle air regulator valve and a small T-shaped valve with a very small, weak spring. This valve closes off the fuel flow. Upon suction from the intake stroke, this small valve lifts off of its seat and allows fuel to flow into the air stream. The adjustable needle valve controls the amount of fuel flow. The mixer itself looked good, with nothing cracked, broken or missing.

I took it apart and thoroughly cleaned it. Everything inside was good. I had to make a special fitting to go from the 1/2-inch pipe inlet fitting on the fuel mixer to the 1/8-inch pipe fitting on the fuel tank so I can use 1/4-inch copper tubing to connect the fuel tank to the fuel mixer. A shut-off valve was already on the tank, so I cleaned it up. There’s also a small, fine screen fuel filter up in the tank. Figure 9 shows the fuel tank and mountings.

The clutch

Early on, the clutch was taken off the engine, set aside – and almost forgotten. It is a heavy-duty looking unit. I took it apart expecting to find a disc-type clutch as it has an over-center lockup system like that on a farm tractor. However, inside it has a steel cone, and it works like putting a Morse taper tool in a lathe tail stock fixture, and seems to be cut at about the same degree angle. It is about 1-1/2 inches thick and 6 inches in diameter (Figure 10). A yoke on the output end shifts it in and out. I had to make a metal mount for the shift lever to pivot on, bolting the mount to the wooden cart.

Other than cleaning and lubricating, the clutch was OK to use. All of the bolts and holes in the clutch had to have their threads cleaned and re-cut with a tap or die. Figure 11 shows the crankshaft, clutch and pivot lever.

The flywheel was sitting loose on the engine when I acquired it. I had not put the flywheel back on, and when I went to do this I discovered there was no flywheel gib key, so I made a tapered gib key from 5/16-inch x 1/2-inch steel stock. I rough sawed it on the band saw and did the finish taper cut on the milling machine. The solid flywheel weighs about 35 pounds.

First fire

I reassembled the engine and was finally ready for a test run. I used 1-inch square wooden stakes to hold the engine in place so I could put a belt on the flywheel and spin it over with my circa-1917 1 hp Alamo (Figure 12). I left the spark plug out of the Grasser and squirted a little oil into the cylinder. As this is an upright engine and the oiler is only on one side of the piston, I wanted to be sure that the whole piston got oil from the top. I also used my automobile timing light to set the ignition timing as I spun it over. After about four or five minutes of spinning, giving it the occasional squirt of oil, I put the spark plug back in – without stopping the engine. The added load of compression made the hit-and-miss Alamo I was using work a lot harder.

Next, I turned on the fuel tank shut-off valve, hooked up the 12-volt automotive battery and after a minute or so it started to pop and make short efforts to run. There was lots of noise and smoke; it made a mosquito fogger look like a child’s toy! After two minutes and some adjusting of the fuel mixer, ignition timing and throttle it settled down and sounded OK. A new neighbor to my west was seen looking over the top of my 6-foot-high fence at all the commotion. I hope she was not offended! I was well into this project when a fellow collector reminded me of how noisy and smelly these old 2-cycle engines are, so I won’t run this engine much.

A question about oil

As stated earlier, this engine has grease cups that lubricate the connecting rod and main bearings, and a drip oiler lubricates the piston. So, do I need to mix gas and oil as a 2-cycle mix or can I just use straight gasoline? At the moment I’m using some chainsaw fuel I had on the shelf. The old fashioned 2-cycle mix for outboard motors was 1/2 pint per gallon, which is very smelly and pollutes the air, so I won’t run it much. The next time I went to start the engine by hand I had no spark; the coil I had repaired that looked so nice had failed! Next winter I will have another go at it.

I want to give my wife, Jackie,  a big “thank you” for all her help on this project!

Contact engine enthusiast Dave Irey at

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