Can anyone explain exactly what the difference between a "Jeweled" motor and one that isn’t jeweled? I have a 1949 Mercury KF5 and a 1962 Clinton Apache which I use Quicksilver gear oil in. Can anyone tell me if these motors are jeweled or not and which kind of lube I should be using, oil or grease? Thanks, Bill M.
Jeweled simply means it has needle or roller bearings. Fully jeweled means all of the bearings are needle or roller, not just some of them. I think Kiekhafer Mercury coined the term.
The KF5 is jeweled, the Clinton probably not. In general, jeweled motors will turn higher RPMs safely. Mercury OBMs dominated boat racing in the 40s and 50s for that reason.
Watchmakers term….jewels (usually saphire ,in rare cases diamonds) were bearings to
prevent wear. A watch with jewels at every location where a jewel was appropriate was
said to be fully jeweled. Advertising implying your outboards were "Fully Jeweled" emphasized
the use of ball and roller bearings feature and implied your product had precision and quality
of a fine watch.
Louis
Actually, except for maybe the cheapest ones, the Clintons were "fully jeweled". They were derived from the Clinton chainsaws.
I think the original poster was actually asking about the gearcase, not the powerhead. I would expect that a Clinton uses bushings in the gearcase but needle bearings in the motor.