Blow-by Oily Smoke

[Ball Racing]

Do your plugs look to have been running extreme lean?
Is there any misfire or constant drop off of power down to or after 1,200 rpms is reached?
Lots of people just have the one electric pump, and probably be a good idea to get rid of the mix of the both types with the way they each function in regard with how they push-pull fuel.

[Orion C&C 33]

Hello Randy..

Welcome to the forum... It's been a while since I've been on.
It's funny that all of your symptoms mirrors mine.

You say your maximum RPM is 1200... It sounds more like your over propped.

You might save yourself a lot of false goose chases by first checking out your prop size. The Atomic 4 is a pretty simple engine and is rated to use 12D x 7P propellor and even states so in the engine manual.

Now with that said, there are members on this forum who have a slightly larger prop ie: 13D x 8P who cruise with it with no issues.

Your engine should be able to cruise at 2200 to 2400 rpms with a max rpm at 2800 rpm.

Like yourself, I could not reach 1400 rpm without the engine overheating and the blow by smoke filled my cabin and setting off the alarms... the front berth hatch had to be left open under sail just to clear the smoke while underway.

Since changing out my old prop a folding Martec 16Dx14P to a fixed 3 blade 12Dx7P my engine can now cruise at 5.9 knots ( clean bottom ) @ 2200 rpm.

Also affected, she burns cleaner and no longer producing the heavy blow-by that filled the cabin or smoky exhaust.

Most importantly she no longer overheats even running at 2600 rpm for extended periods and holds steady at 140 degrees on the gauge.

Time is money... I would recommend you explore first your current prop size before checking anything else on your engine.

Cheers.

[roadnsky]

Orion-
Please note that Randy's post is from 9 years ago (2012)

[Orion C&C 33]

Thanks just noticed it after I hit the reply button...