Yamaha 2 stroke oil systems

[sec56]

Looking at a couple of boats powered by Yamaha 70hp and 90hp outboards (2 stroke). I know that the 90hp's are 1990 model year. After receiving information and opinions on VRO systems, I was wondering if Yamaha had the same/similar issues with the oil system, how dependable they are, and what to look for before failure.

 

[robert graham]

Re: Yamaha 2 stroke oil systems

I run a 1999 Yamaha 90C premix, no oil injection, just one less mechanical system to clutter up your motor and to worry about(my opinion)...oil injection systems are about as dependable as they can make them, but if/when they fail, it can be bad news for the motor. Many of the motors have alarm systems for low oil that can offer some degree of protection. The oil remote tanks, pumps, sensors and oil lines have been known to give trouble. About the only way for a premix to fail is by forgetting to add the oil while filling your tank. That said, I had a 115HP Yamaha with oil injection for a couple of years and never had a bit of trouble out of it! Good Luck!

 

[99yam40]

Re: Yamaha 2 stroke oil systems

Yamaha has the gear driven pump off of the crank shaft, not the VRO pulse driven pump.
Very reliable just keep tanks clean and test from time to time like Yamaha recommends

 

[sec56]

Re: Yamaha 2 stroke oil systems

If I buy this boat with these 90 hp motors and decide that I want to mix oil and gas myself, is there an elimination kit available for the pump. Obvisiously, if I don't eliminate or disable the oil pumps, an alarm/warning should sound. Also, the model number was sent to me today. Seller was the one who told me they were 1990 motors, but based on model received today, they are 1995 engines.

 

[Capt Ken]

Re: Yamaha 2 stroke oil systems

Why in the world would anyone in their right mind want to premix. Yamaha has the most trouble free system and causes less problems than premixing will cause.

 

[robert graham]

Re: Yamaha 2 stroke oil systems

Why in the world would anyone in their right mind want to premix. Yamaha has the most trouble free system and causes less problems than premixing will cause.

Simplicity and total dependability....

 

[Capt Ken]

Re: Yamaha 2 stroke oil systems

Mixing leads to over oiling and hotter fuel burn. Also, Yamaha engines use different jetting in the oil injected engines and the C model. Premixing changes the viscosity of the fuel being Yamaha injects the oil directly into the intake which differs from other makes that mixes the two.

 

[robert graham]

Re: Yamaha 2 stroke oil systems

Another endessly debatable subject, but you'll probably agree there's darn little to break with a premix lubrication system, And premix does provide better internal motor parts corrosion protection since oil/fuel ratios are highest during idling/low RPM operation just prior to shut down(especially for several days/weeks in a saltwater or marine environment). I can't see where premixing has caused me any problems at all on my 1999 Yamaha 90C...still running the original spark plugs! Good Luck!

 

[dpfundst]

Re: Yamaha 2 stroke oil systems

I have a 2001 yamaha 90hp 2 stroke.......with oil injection.....works great..

 

[yamatech43]

Re: Yamaha 2 stroke oil systems

Listen and just enjoy the most dependable motor made.....nothing wrong with Yamaha oil injection. If you want to premix just buy a Johnson, you'll save a lot of money and It'll smoke up the marina at least as well as any other on premix....

 

[Bamaman1]

Re: Yamaha 2 stroke oil systems

The Yamaha oil injection system is mechanical, and it's very, very dependable. The oil tanks, buzzers, etc. are actually separate of the oil injection.

The big remote oil tank has a float in it that will produce a buzzer then a fail safe mode if the oil level is too low. The small oil tank on the engine also has one of the floats, and it sends a signal through an electronic module to the big tank when the small tank is full--to quit pumping oil.

Only problem I ever had in 26 years usage was with the electronic module (w/switch) when it wouldn't tell the big pump to quit pumping when it was full. The part was about $250.