Rage

I had always heard that one of the last things you want is for the oil to foam. How can one of the best gear case lubes have a foaming tendancy?

Rage

I have two Yamaha FX HO (160hp). One is a 2005 and the other is a 2006. The Owners manuals are dated Jan 2004 and September 2005 respectively but both say 10W30.

Rage

Yes the Amsoil
SAE 10W-30 Formula 4-StrokeŽ
Marine Synthetic Motor Oil (WCT) looks to be the best choice. Is it a full synthetic base?

phebus

What did you get grandma, a quart of V-Twin?

Happy Holidays, and thanks for all the advice.

minxguy

It is not "foam" like shaving cream foam. It is called air entrapment. Never useing the Redline stuff but reading about it, people have said it is a messy fluid, kind of like liquid silicon, I am guessing that there is an additive called a tackifier in the blend to help the oil "climb" up the gears. This additive is also found in bar & chain lube or in any application where you whant to retain the lubricant on the surface; chains, cables,etc. The tackifier will increase the viscosityof the fluid making it harder for air bubbles to escape when the oil is cold. When the oil heats up and thins out, the bubbles escape more easily. Take cold gear lube and whip it up in the blender and then do the same with hot oil ...big difference. You will also have then same "air entrapment" condition using very heavy straight weight oils. Older harleys are famous for this. Pull the drain plug on the oil tank and oil will drain out, as you get near the end of the drain, its all bubbles. Although the straight 60 and 70 weight oils do not have a tackifer added, the results are the same because of the heavy viscosity of the oil.
Tackifir, when added to oil will make "working" with it more of a problem then "working" with an oil without it. Just pour some bar 7 chain on the floor and start cleaning it up.
Ken

Rage

Excellent explaination! Much appreciated.

I can attest that the Redline gear lube is messy stuff as well as chain saw lube which like to leak out of my saw over the summer. I put up with it because I thought that it was the best for my drive.

I remember an owners manual warning against overfilling an automatic transmission that if overfilled could result in the oil foaming. This was a warning so the implication was that damage could occur. Is that not the case with the foaming of the gear lube in a drive?

Knot 4 Me

Rage, my friend's ski I'm referring to is an '06 VX Deluxe with the 110 HP 4-stroke. Its manual states a variety of oils ranging from 5W-30 to 20W50. Surprised the heck out of me since my 140 HP called for 10W30 only and the 110 HP is simply a detuned version of the same motor.

minxguy

In all honestly, I really can't beleive a modern day quality lubricant foams. The anti-foam additve that is used in oils is added at very low percentages and is probably already in the dertergent package that the blender buys.
I really do not know how you how you overfill a lower unit seeing how you fill from the bottom until it flows out the top hole, but stranger things have happened.
As far as you automatic transmission, overfilling wouldn't cause foam, what it causes is the oil to "puke" out from overfilling. Oil expands with heat, if you start with an oil level that too high, when it expands it will be even higher. It could "grow" enough to puke out the fill tube or push out a seal/gasket. This could be the same issue in a outdrive.
A quat of oil is a quart at 60*F. This is buy/sell temp of oil. At lower temps you have less than a qt and at higher temps you have more. This is the reason engine manufactures want you to check you oil the same way evey time. BMW automatics have to have their transmission oil checked at a certain oil temp, a real pain in the ass.
Anyway, I hoped I helped.

Ken

o2man98

Yes the AMSOIL Marine motor oils are full synthetic base stocks.
10w-30 = http://www.amsoil.com/StoreFront/wct.aspx?zo=1132530
10w-40 = http://www.amsoil.com/StoreFront/wcf.aspx?zo=1132530

The nice thing about these oils is that they use a base and additive package very similar to the new Motorcycle Oils. This is the chemistry that I see AMSOIL going to in more and more of their motor oils in the future. They have also added the Small Engine SAE30/10w-30 oil which also share similarities. http://www.amsoil.com/StoreFront/ase.aspx?zo=1132530

Take a look at this report that shows how the AMSOIL motorcycle oils stand up to the comp. http://www.modernoils.com/media/pdf_...Comparison.pdf

Rage

Yes that is strange that the same motor has different recomendations. That is one heck of a range of oil viscosity for the 110 hp.