How does the crankshaft stay lubed in an outboard.

[32251]

I have been learning how to fix my outboards.

I was just wondering how the crankshaft and all the stuff hooked to it gets lubricated during operation? I understand car engines and lawnmower engines as they have oil in those areas that is either pumped or gets oil slung on it.

How do outboards lube the cranks, journals, wristpins etc. I can see that the rings and cylinder walls are lubed by the oil in the gas. Does some of that oil somehow get to other areas of the engine.

Thanks for the info.

 

[robert graham]

Re: How does the crankshaft stay lubed in an outboard.

that's what the gas/oil mixture is for, it passes through the crankcase before being forced through the ports and into the combustion chamber. everything gets a bit of oil on it that way. also you'll notice that 2 stroke outboards, our any 2 stroke motor has needle or ball bearings for main, crank and wrist pin bearings, not plain/babbit bearings like on a car that requires oil pressure to maintain the lubricating oil film between the journals. so that's it, the 2 strokes and 4 strokes are totally different animals. Good Luck!

 

[d.boat]

Re: How does the crankshaft stay lubed in an outboard.

http://science.howstuffworks.com/two-stroke1.htm

 

[5150abf]

Re: How does the crankshaft stay lubed in an outboard.

It is actualy pretty amazing they work at all much less run for years and years.

I have an '81 50 Evinrude with the original power head and it still has 145 compression.

I always mix my gas then add a bit for insurance.

 

[sho3boater]

Re: How does the crankshaft stay lubed in an outboard.

Modern 2 stroke oil is specifically made to do this, you may find very old engines that tell you to put a lot of oil in like a pint per gallon of gas. That is for normal oil not 2 stroke oil. The oil collects on the parts and burns better when it gets in the cylinder than normal motor oil would. This is also why it is a good idea to fog a 2 stroke for long storage, though they rarely get moisture in the case if kept dry. Some of the new direct injection outboards do have a pressure oiling however, in an effort to limit the oil that gets burnt and causes more emissions. They can operate on very little oil and achieve emissions a 4 stroke makes.