TOPIC: 1958 Mark 58a Super Thunder Bolt

Before starting this thing up I want to change the fluids and the impeller. I've been looking at a lot of online sources and some say the impeller is the same for all 40-50hp Mercs. Is this true? Or are impellers specific to this model? Where would be a good place to find the impeller? What other recommendation's would you make prior to me starting this motor? It hasn't ran in 4 years and then only for a minute. I've heard with modern 2 stroke oil you can dilute it much more with the gas. What is a good ratio? What's a good gear oil? Spark plugs? do you recommend carb rebuild kit or just clean it out really good? Thanks in advance.

yes on the impeller. get a good quality one merc is best. I would use 25-1 for first start up plugs were j6j but after running check the color. do the mag set points tight .010. call me 1 914 310 7086. Dave.

Don't skimp on the oil. Some will say you can run it 50:1. It might very well run just fine with it. Yes, new oils are better than the junk they ran back in the 1950s. But, parts are getting harder to come by. Run it as it was originally recommended. Do a decarbon periodically using any of the Sea Foam, Engine Tuner, etc. elixirs.

And, yes, the impeller was the same on the classic 40/45 cube Mercs through the entire run.