1958 35 Rude, 1960 Jonny 40 ?-same??

[kodibass]

I was given a 1960 Jonny super seahorse super quiet RDS-22 and it has a hole in the block behind and above the fuel pump. I have not disassembled it yet to inspect the internal damage, I also have a 1958 Rudy Big twin 35 hp with a decent block was wondering are they the same block? They Jonny is complete the twin is just a powerhead, so was thinking could I swap power heads and make the Jonny usable??

 

[Chinewalker]

Re: 1958 35 Rude, 1960 Jonny 40 ?-same??

Similar, but not the same. The 40 has a few more cubic inches due to a larger cylinder bore. I think as a unit, you could swap the powerheads. Bolt pattern, recoil, ignition, etc. are the same. The flywheels may or may not be the same, depending on how original the 40hp powerhead is - many were swapped out for larger crankshaft powerheads due to broken cranks. If the crankshaft tapers are the same, you should be good to go with the flywheel.