Engine Flushing

[Gimme5]

Just wondering are there any good reasons why an outboard, in particular a 150hp 4s can't be flushed in the fully tilted position using muffs?

[Darren Mc]

Do you mean with the muffs on and the engine running?
If so the engine should not be run in the fully tilted position because a four stroke has oil in the sump and when fully tilted the oil pick up will not be sitting in any oil. It must be in a position no higher than what you could have it out in the water while operating with it trimmed up in shallow water or something like that.
Really it should be flushed in the down position or close to.

[thelump]

Most outboards these days have a flushing port that you attach the hose to and flush without running the engine. I think this is designed, partly, for people with moored boats that cant really muff flush and tilt the motor to get it out the salt and attach hose.

[SunnyCoastMark]

Most outboards these days have a flushing port that you attach the hose to and flush without running the engine. I think this is designed, partly, for people with moored boats that cant really muff flush and tilt the motor to get it out the salt and attach hose.

I think you'll find that they still recommend flushing using the muffs as the water pump has to be running to circulate the fresh water through the motor properly. You are riight in saying it is designed as an aid for people whose boats are permanently moored.

Mark

[PeterKroll]

Yep, I have asked this question (after buying the fitting for the flush port.. Doh!) and Honda said exactly that.. Flush with ears. That port is, as you said, for boats that are permanently moored.

[Gimme5]

Thanks for the comments. The flush port is certainly not a substitute for running the engine while flushing but having said that, I've done it for years without issues even though salt does build up in places. I'm technically challenged so for my own understanding, I've always wondered why the engine has to be in the running position (as opposed to fully tilted) to start and flush. So Darren going by your explanation, you can do it for a DI 2 stroke OB?

[WalrusLike]

I wouldn't trust the flushing even a two stroke on muffs with motor angled.

For all I know it may be ok but it's water..... it doesn't run uphill. If the motor is angled I can imagine some portions of the galleries might not get flushed.

Could be wrong but I personally wouldn't risk it.

[Triple]

Do you mean with the muffs on and the engine running?
If so the engine should not be run in the fully tilted position because a four stroke has oil in the sump and when fully tilted the oil pick up will not be sitting in any oil. It must be in a position no higher than what you could have it out in the water while operating with it trimmed up in shallow water or something like that.
Really it should be flushed in the down position or close to.

Looking at the depth of the sump and oil pickup of most 4 stroke outboards they will pick up oil at extreme angles.. Think of the angles the outboard sits at trimmed out when in huge swell or going through the breakers, you think manufacturers want oil starvation in those conditions? Carbed two stokes are probably more of an issue with float bowl levels at those angles... still I would level it out too if I can. The question must be asked why? It takes 2 secs to lower it.

[Darren Mc]

I agree with what you are saying triple but when you flush your motor it's sitting there running for 5 minute's or more at whatever position you have it in. When out in the swell etc your engine would only be at any sort of a slight angle for very short periods ( seconds)which I think makes a big difference between the two. Maybe they will pick up oil at any angle, but i wouldn't risk it personally.