Low budget Outboard Pre-Lube Pump (4 Stroke only)
- Dave LeGear
- Feb 22
- 4 min read
Updated: Mar 20
The reason military and many other industrial-grade engines last so much longer (other than being built for such and running expensive lube oils) is that they employ pre-lube pumps to circulate lube oil throughout the engine before it is lit off / started.
This is one of our long-standing checklist items from when I was in the USCG, and yes, this was well past the use of Cannon Balls and Sails for those calling me OLD! 🤣 Was to bring online and ensure we had X amount of Oil PSI before the crank was spun over a single degree.

So, I was looking to employ such thinking on our past Yamaha F70 Outboard, especially after an engine oil change. I discovered that "if" I left the red kill safety switch insert disconnected (unlike my past BF150 Honda), I could spin the engine over for some time, and it would not start, basically making it into a low-budget Outboard Pre-Lube Pump.

This is great! Though it is not an actual pre-lube pump by design, it allows one to spin the engine over and let oil pressure build up since the oil pump is a mechanical unit before putting fire to any cylinders. As such, anytime I start the engine now, I leave the kill switch disconnected and spin her over for 5 to 10 seconds to build up oil pressure inside the Engine before I reach down and insert it for the final "Light Off."
Now, will this help any? Well, it's much better than the engine going from setting (sometimes for days or longer) and starting right up with many components dry, now under a full load, and getting hot real fast, than having no oil circulation period. Also, it is a good practice after making an oil change, and almost all the new oil is just sitting in the oil pan so you can move that fresh oil around the engine.

Some might argue that this could be tough on a starter. If you were to hold the ignition switch for an extended time, I might agree. That’s why I keep it brief. In the long run, I'd much rather replace a starter than rebuild the top end or the entire engine. Remember, there’s no need to crank it for too long.
This was tested on my 2013 F70 and my 2022 115 SHO Yamaha, and I "suspect" that is how Yamaha makes all its more recent ignition switches. It might work the same for you. It is easy enough to test for sure. It could work for other makes/years of Outboards, knowing how they all source many of the same parts from the same vendors. My past 2004 Honda would not even turn over if disconnected. Again, it is easy to test if you want to try this process and, if nothing else, to ensure your safety switch works as designed. I would ensure water is hooked up and flowing through a set of muffs and the prop is clear before trying.
I hope this helps extend your Outboard's life. Let us know your results! 👍
Along these same lines, and to help save on some more wear and tear on your costly engines! You may want to read our product coverage on (quite telling) a very efficient way to help save on those engines and afford a great ROI versus repairs or rebuilding one.
So, try one and see how much longer your oil stays cleaner. This is when those sub-20-micron little particles of metal that are now passing through your oil filter media (usually just paper) are getting stopped there. This and not acting like tiny particles of hard metal sand circulating in your expensive engine. I recommend starting your search for one regardless of the application (Marine, Automotive /RV) by first clicking Here.
And do let them know that Flats Nation sent you and that we have a promo code for you to use when ordering! Just use "FlatsNation10" to receive 10% off on your entire order 😊
In the meantime,
We invite you to take in a few Flats Nation Podcast Episodes to help "Scratch that Fishing Itch" when working or traveling and you cannot hitch up the Skiff and go by clicking Here:
Plus, our store has some new clothing and items you can review and order by clicking here.
Tight Lines, and God Bless!
Dave and the Team
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