Johnson Iron Horse
There isn't a lot of information available about these old engines. According to information received from Johnson collectors this Model X305 was manufactured in 1936 or 1937. I don't have any hard proof of that date estimate. I was also told that the clamp style exhaust elbow was to accept a flex hose. That would confirm this engine to be a washing machine engine. It has compression and some spark, but needs a good bit of cleaning up before I can attempt to start it. I've decided return it to running order, but to leave it in as received condition. I will not be repainting this one. It just looks too good as is.
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Best way to clean up an old engine is to clean it out first.
Here is the cleaned bare block. The cylinder bore and piston looks good.
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The engine gets it lubrication from this trough in the base. The cam gear runs in the trough splashing the oil throughout the engine.
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The magneto plate cleaned is up. A I said earlier it had a little bit of spark, so I'm hoping a good points cleaning will make it better. I'm also hoping that external condenser is good. It wouldn't be hard to find a workable replacement, but I like the looks of the original.
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The crankshaft journals are all smooth and mic round. The middle picture shows the flyball type mechanical governor. The third picture shows the crank gear timing mark.
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The cam checks out to be fine. The two punch makes on the cam gear are the timing marks that will line up with the crank timing mark at assembly.
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The suction carburetor is a rather simple design. Everything cleans up easily and is in working order.
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With everything cleaned up, it's ready to begin reassembly.
New gaskets are hand cut.
With the crankshaft slid into place, the first thing I did was insert the governor arm blade. It's a little tough to see if the blade is in the groove of the governor ring on the crankshaft, but I got it on my second attempt.
The piston was then installed using a small ring compressor. I have no specs for this engine, so I just went off experience and torqued the connecting rod cap screws to 120 inch pounds. After that the keeper tabs are bent up against the flats of the bolts.
Next thing to go in is the camshaft. The second picture shows the alignment of the timing marks.
After the mag plate is bolted on the flywheel and head are mounted. Again guessing at the proper torque, I tightened the head bolts to 220 inch pounds. At this point I check the spark. It jumps a nice thick blue arc across the plug.
The kick pedal in held in place with a C-clip and a little challenging to get into the groove. The return spring is fitted into the correct holes, and it works fine.
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All that was left was to bolt the carburetor on, attach the governor arm, and finished!
A little whiff of fuel and it fired a few times. I'll be attaching it to a Briggs fuel tank to see if it will run very soon!
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OK 12 hours have passed. It's Sunday morning 8:00AM I think it's time for this neighborhood to wake up anyway....
I borrowed a fuel tank from a Briggs WI and mounted the engine to a plywood running stand.
A little adjusting, a few kicks of the pedal, and it's alive.
This is a great little engine!
