Reply To: Random questions about my 1958 Johnson RDS 20

[TJ Brandon]

Thanks all for the responses. The coils I put on read right around 8k each. My first step will to clean the points, if that doesn’t work I will take the coil back out and re-seat the plug wire again.

I had no idea hooking up an rpm gauge would be that easy and cheap. I have one ordered from Amazon now. I also learned they have GPS speedometers, I thought those were pretty neat so I ordered one as well.

For the prop, thanks I have saved the links. Unfortunately the first snow just fell in Michigan so it will be a while before I can water test this thing. So the strategy is to measure rpm’s at WOT with typical load then adjust from there.

For the oil – yes I think the cheapest tcw3 oil I found is from walmart at $20 a gallon. I may have to have the oil truck just stop by my place once a week. 🙂

One more question – when I was replacing ignition components I noticed the timing was off. The carb linkage was engaging about 1/4″ before the line on the throttle cam. I have worked on a couple 50’s 10hp and this is easily adjusted with the adjustment screw. On this motor though, the cam is all the way pushed in and still engages 1/4″ too soon. I’m assuming this should be dead on the line the same time the carb linkage starts to engage?

BTW, this is the project I am working on https://www.aomci.org/forums/topic/1963-mirrocraft-with-1958-johnson-rds-20/#post-292224 and attached is a picture of a 10hp we went through that now runs amazing for my sons boat.