Synthetic Oil

[chickenofthesea]

Has anyone used synthetic oil in four-strokes? What about lower unit oil? Is OK for my warranty? Thanks

[boats.net]

Yamaha doesn't list it as a acceptable oil, they require an oil with NMMA FC-W certification. Don't use it during breakin period.

[chickenofthesea]

This is on amsoils website . 4-Stroke Outboard Motor Warranty Certified
Formula 4-Stroke® Marine Synthetic Motor Oil is certified by the National Marine Manufacturers Association (NMMA) for use in four-stroke outboard motors. This high quality oil demonstrates outstanding performance, exceeding the NMMA “FC-W” (Four Cycle-Water) specification requirements. Formula 4-Stroke® Marine Synthetic Motor Oil fulfills the warranty requirements of four-stroke outboard motor manufacturers.

• NMMA Registration #FB-30011B 10W-30

[Beverly Synthetics]

4- Strokes and Synthetics

Synthetics are the best options for todays engines. They offer peak performance, better emissions, better fuel economy, and engine wear protection. These benefits are applicable in the inboard/outboard markets as well. Amsoils 4-stroke Marine Synthetics just as some of the other members have posted meets warranty criteria fo most engines and exceeds the NMMA-FC-W requirements. I see some posts in regard to break-in and I see no reason for it not to be used then as well, but it is at the discretion of the user and manufacturer specs. For more product information on synthetic 4-stroke oils and filtration visit: Beverly Synthetics - Home page .

[Reel Insane]

I ran into this situation earlier this year with a warranty claim. The manufacturer did not void the full warranty but did pay for parts only. The reason for this was because the manufacturer did not test the engine and components with synthetic oils.

As far as I know, and what I can research, Yamaha does not test their engines with synthetic oils either.

I would research as much as you can before making such a drastic change. Remember, once you start with synthetic you can not go back (or should not go back) to conventional oils. The molecular structure of the oils are completely different and are not compatible (even if you flush your engine).

Yes, I do know that Amsoil makes a semi-synthetic oil. It is blended during manufacturing and it is a pretty good oil.

I know there are myths in the automotive industry about using synthetic oils for break in. Reality is there are numerous manufacturers that send cars out of the factory with synthetic oil.

If it was my engine I would break it in with conventional oils. Then switch to synthetic after-wards to help with wear.

I always tell people this: When adding oil to your engine shake the bottle of oil first. Then pour oil in the engine. The reason for the shake is to re-disperse the additives which fall the to the bottom of the container while sitting on the shelf. Since the additives are heavier than the oil they sink to the bottom while waiting to be sold. I have seen oil sitting at warehouses for almost a year or longer before it is sold to the public.

Good Luck with you decision.

[stevenspencerlittlesr]

Why can you not go back to conventional oil after running syn? I worked at as a mechanic fo five years at a quick lube and have never heard this, nor the shaking of the bottle?

[Reel Insane]

Okay, shaking the bottle before you add the oil to the engine disperses the additives throughout the oil. When oil sits for extended periods of time the additives settle to the bottom of the container. It is the same principle as shaking your medication up in the bottle before you take it. When additives are added to the oil it becomes a suspension. As all suspensions without movement the suspended particles fall if they are heavier than the liquid in which they are placed.

In quick lube and dealership environments bulk oil is circulated with a pump and filtered before installed in engines (or supposed to be). The circulation pump keeps the additives from settling to the bottom of the tank.

Synthetic VS Conventional Oils

Both oils are made from crude oil. Most people believe that synthetic oil is made in a lab and this is not true. Synthetic oil is considered a designer molecule. Engineers rearrange the molecules in order to achieve superior lubrication performance. Like conventional oils additives are added to help with cleaning, corrosion protection, acid build up, and sludge build up to name a few. Synthetic oils also bond with the metals inside your engine to aid in dry starts. Synthetic oils are also used to increase fuel economy, reduce engine wear, and increase engine life.

The major oils companies state that you can switch back and forth from synthetic to conventional oil depending on the state of your engine. Oil companies say that you should not switch back and forth if your engine has a lot of blow by or is known to have any internal damage. Switching back and forth can also cause oil leaks and premature seal erosion. The practice of switching back and forth is frowned upon by the commercial automotive industry and by almost all the light duty technicians I speak with. I should have not said you can’t switch but should not switch back and forth.
With this being said, I have personally seen a catastrophic engine failure due to the frequent change of synthetic and conventional oil.

With synthetic oils being superior to conventional oils why would you want to change back and forth?

One more thing, some people are under the impression that you can extend the engine oil change interval because of the use of synthetic oil. ALL oil manufactures state that you should not exceed your manufactures engine oil change interval. Oil companies also state that you should follow the oil viscosity provided in your owner’s manual.