Re: 1972 Johnson 125 HP hydro electric??
I ran a 100 hp version from 1972 for many years. It gave me great service the years that I owned it. No problems, though that was many years ago. The 125 was the high performance engine from OMC that year... These engines are older now, so there are some concerns regarding them. The electric shift lower units work fine-when they work. Problem is -few folks still work on them and many of those unique electric shift parts have been discontinued. They do take a special gearbox oil. The powerhead is fine and likely most parts are still avail for it, including the major electrical ignition components. If it runs fine and you plan to keep it, you will want to get an original factory 1972 service manual. You can get it from Ken Cook Co., in Milwaukee. Also, the original factory parts lists are available online at: epc.brp.com. I'd make sure you run the right octane fuel in it, as fuels have changed since then. It is possible that it requires 89 fuel. The engine was produced before ethanol, so all the fuel lines under the cowling are not made to withstand today's ethanol fuels. You may want to order new lines and replace them before it causes a problem. Order the original fuel line part #'s from Bombardier and you will get replacement factory ethanol resistant fuel lines. Your engine was hp rated at the crank so it doesn't directly correlate to today's hp engines. Sometime around 85-86, all outboards changed their ratings. Newer outboards are all prop rated now.
