RDS23 andRDS27A; differences?

[andiemarie]

My 40h RDS23 is giving me fits; (1961) and I am looking at a 40h RDS27A. (1965) They look identical, anyone know of any big changes during that 4 year span I should look for? I'd like to use the 1961 for parts for the 1965 if need be. Thanks. Andiemarie

 

[steelespike]

Re: RDS23 andRDS27A; differences?

From a aftermarket service manual these motors appear much alike.Bore,stroke and displacement are the same.Depending on the model the 65 may have an automatic choke.The 65 has a fixed high speed jet.I think you will find lots of parts that will interchange.The 65 is 50:1 mix and will probably do a little better on gas.

 

[Paul Moir]

Re: RDS23 andRDS27A; differences?

There are some small internal differences between the two. But big parts will interchange like the lower unit, engine, etc. From specifications it's clear they changed the piston, I think the wrist pin bearing changes on the '65, and I'm pretty sure there's some internal lower unit changes involving the thrust bearing.<br /><br />But like steelspike indicated, they're almost identical. So long as the '65 is mechanical shift anyway.

 

[andiemarie]

Re: RDS23 andRDS27A; differences?

Thanks steelspike and Paul! I did get the 61 to run OK (Paul, you helped with this, it was choking on its exhaust) but it would never open up so we finally found someone here to take a look at it and found one of the cylinders has no compression, and needs more work than I can do or am willing to pay big bucks for so at this point it is cheaper to buy the 65 and use the other for whatever parts. Any big problems with the 1965 rds27a that you are aware of that I should look for? Thanks again!

 

[Paul Moir]

Re: RDS23 andRDS27A; differences?

I don't know of any problems at all, other than the ones you're familiar with. With these older outboards it's always a good idea to have a spare parts engine if you're willing to put up with the clutter.