FX 140 - synthetic oil

[Rambling Wreck]

I have 140 hours and was ready to change to Mobil 1 synthetic oil. I recalled that the initial owner bought a 7 year warranty so I decided to call the Yamaha dealer just to check. They were adamant that I NOT use sunthetic oil. I never got a clear explanation as to why. Would like to hear from those that know these engines and oil.

[David3aces]

Re: FX 140 - synthetic oil

I don't know much about oil, however I change mine often because of the fact that I can only remove about two and a half quarts from the 4-5 quarts the engine holds. Today's motor oils are far better in quality then 15-20 years ago and I feel comfortable knowing it's fresh and clean. Use regular oil and don't worry about it.

[leon phelps]

Re: FX 140 - synthetic oil

Synthetic oil and water mix way worse than regular oil and water. Since the ski will be used on a boat, there will be water in the oil even if it is a small amount. I have had lower units that with synthetic oils took in water and with regular oil did not. It know it sounds strange, but for some reason the synthetic oils did not keep the seals working properly. The oil I was using was marine synthetic for the doubters.

I have also seen synthetic oils burning off in cars, when regular oil did not. I know it sounds crazy, but it is true.

[Riixxii]

Re: FX 140 - synthetic oil

Looked in the S.M. today and nothing about NOT using a synthetic. On another note, the Sea-Doo 4-strokes that are normally aspirated can run the synthetic but the supercharged version ABSOLUTELY cannot. It can ruin the supercharger clutches. A high quality 10w-30 changed on a regular schedule, thats what I would do.

[joeyo]

Re: FX 140 - synthetic oil

I have two 2005 FXHO and when I got the 10 hr service done I asked the dealer. He said that they recommend using the Yamaha 4 stroke oil.

My additude is that I will change the oil & filter once a year. I spent over $22K for my two FXHO, so $50 (2.5 qts per machine @ $5.50 per qt + $11 per filter) per year on Yamaha oil and filter should not be a big deal. But that is my personal preference and decision. Also since I have the extended warranty, if I have any issues with the machines - it is nice to say that only Yamaha oil and filters have been used.

I have a friend that has used Mobil 1 in his waverunner and had no problems. I think he saves maybe $10 on his oil and filter NOT using the factory oil & filters.

[addicted]

Re: FX 140 - synthetic oil

I really know nothing about 4 stroke ski's, but i know that synthetic in a bike causes the clutch to slip and wear out because it is too slippery. I like leon's reply. it makes the most logical sense.
Just my 2c
:emoticonc