Head gaskets and crank seals

[stanley]

Having tried every alternative I need to take a look at the rings in my 1931 Johnson A-50.The question is,are head gaskets available and what about crank seals?If gaskets are not readily available what material should I use to make one?

[Anonymous]

A50 uses no head gasket(cyl. and head cast as one piece), just cyl. to crankcase gskt. and uses long bushings for sealing the crankshaft( no seals used). It requires using 1/2 pt. of oil( do not use 30or 40 wt. non detergent motor oil that was the original recommendation) to 1 gallon of gas.Use a modern TCW III oil of your choice. The old style oils caused carbon to form and caused many problems. The higher concentration of oil acts to seal the crank ends and to seal the crank shaft rotary valve. A modern spark plug to match the original heat range is the Champion D9 #509 gaped at.030 Good luck and enjoy running your motor. When starting motor make sure to open the exhaust relief port.

[Anonymous]

No gaskets are available you will need to make your own using the originals as patterns.Use a material that is similar and of the same thickness. The original cyl. to crankcase gasket material was similar to a brown paper sack. Measure and match the original gasket thickness, to maintain the original port timing.

[stanley]

Thanks for the answers.I did mis-speak when I said head gasket.The info was encouraging.

[Anonymous]

Early to mid production A50 and K50 motors did not use sealing rings in the crankcase to seal the center main between cyls. and as the motor wore this could show by poor starting and poor running. But if not worn these motors are nice running.

[stanley]

This motor does not seem to be really worn.How likely is it that the center main is the issue and is there a way to check it without removing it.The motor hits but has never run for more than a few seconds.Carb has been cleaned twice and motor has spark.I have cylinder off now and am going to replace gaskets(which were sketchy),check rings etc.I’d hate to put it all back together and wished I’d checked that out.

[Anonymous]

What is your serial number stamped on the crankcase?

[stanley]

25d2

[stanley]

Sorry looks like15370

[stanley]

Let’s try that again with more light.153701

[Author]

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