keeping a 4-stroke tilted up

Is it ok to keep a 4-stroke outboard tilted all the way up?

I'm hearing conflicting advice on if it's bad for a 4-stroke to be horizontal for too long.

 

Most outboards spend 90% of their life in tilted up position. No sane manufacturer constructs an engine that cannot handle normal use.
It may be advisable to wait a few minutes before starting the engine after lowering it, especially in cold climates.

 

Well, there might be two sides to this coin that are getting confused.

Generally, having the motor tilted up puts more stress on the transom, and I know that I have always heard, and paracticed, never trailering or stowing a trailered boat with the motor tilted up.

On the other hand, I had a Yamaha 9.9 4-stroke on my Ranger 26 (Mull) that lived tilted up while it was in the water for all the years I had the boat.

Edit to add, I do recall however, that if you ever laid the engine down (totally horizontal), it had to be in a specific position...<shrug>.

 

These is something that comes up occasionally and it's usually just a bit of confusion over laying the engine down for storage or transport and it's position in use.

An outboard can live in it's tilted up position indefinitely. Generally, they live in this position 90% of their life, probably longer. The question only comes up when you read the owners manual and see that most 4 strokes, are required to be laid down on their side for storage or transport. Most need to lay on a specific side, often having leveling bosses or studs on the case and cover, to help support then engine while it's on it's side. It's important to lay the engine on the side it's designed to live on, but this is the only time it's necessary to be concerned about it. If hanging on it's bracket, any position the clamp permits is acceptable, including all the way up.

 

I've heard that in freezing climates, leaving it tilted up allows the foot in the propeller shaft area to collect water/rainwater which then freezes and can cause problems. Leaving it in running position allows it to drain out of there.