Johnson 90 HP

[martyouel]

Hi,

i'm looking to buy an used boat which is powered by a Johnson 90 HP 4 cylinders with oil injection.
What's that mean..."oil injection"?
Is it an engine that we need to mix oil with gas?
Is it a trustable engine?

Any comments about that engine will be appreciate.
Thank you

 

[billsnogo]

Re: Johnson 90 HP

I just got an Evinrude 90hp VRO (variable ratio oil?) that has oil injection. If the oil injection is not unhooked, that means you have two tanks to keep full, one of gas, one of two cycle MARINE oil. Most outboards are two cycle (needs gas and oil mixed together) and this system mixes the ratio for you instead of dumping the oil into the gas tank.

 

[tashasdaddy]

Re: Johnson 90 HP

what 90 hp Johnson, they have been built since the 1960's. year model #.

 

[Chris1956]

Re: Johnson 90 HP

Marty, Johnnyrude motors with oil injection have a special fuel pump that mixes 2 cycle oil from a resevoir with straight gasoline from the fuel tank. There have been several models of this special fuel pump made over the years. The early ones (80s -90s), called VRO were not as reliable as the newer ones (1996+) called OMS, so depending on the year of the motor you buy, it may have been disconnected. If the oil side of the fuel pump has been disconnected, you need to mix 2 cycle oil with the gasoline in a 50::1 ratio.

If the oil injection is still connected, I recommend you test it. The easiest way to test it is to fill the oil resvoir to the top, and mix up 6 gallons of 50::1 fuel in a remote tank. Run the motor on the premix, until it is empty. Now see if the resvoir will accept 16 oz of 2 cycle oil. If so, the injection is probably OK. If it will not take the oil, the injection is probably faulty, and you should stick with premix.

 

[billsnogo]

Re: Johnson 90 HP

Marty, Johnnyrude motors with oil injection have a special fuel pump that mixes 2 cycle oil from a resevoir with straight gasoline from the fuel tank. There have been several models of this special fuel pump made over the years. The early ones (80s -90s), called VRO were not as reliable as the newer ones (1996+) called OMS, so depending on the year of the motor you buy, it may have been disconnected. If the oil side of the fuel pump has been disconnected, you need to mix 2 cycle oil with the gasoline in a 50::1 ratio.

If the oil injection is still connected, I recommend you test it. The easiest way to test it is to fill the oil resvoir to the top, and mix up 6 gallons of 50::1 fuel in a remote tank. Run the motor on the premix, until it is empty. Now see if the resvoir will accept 16 oz of 2 cycle oil. If so, the injection is probably OK. If it will not take the oil, the injection is probably faulty, and you should stick with premix.

Can you just run premix on a VRO without changing the fuel pump without any ill-effects?

 

[martyouel]

Re: Johnson 90 HP

Thanks guys for your answers.

The boat I'm looking for is a year 2000...so I think the engine is a 2000 too.

So, this engine is a 2 strokes engine but I don't need to mix my gasoline with oil myself, am I right? If yes it's a pollutant engine?

I'll try to get from seller the exact model of engine.

Thanks again for your time.

 

[Silvertip]

Re: Johnson 90 HP

Read these responses again -- very carefully. IF the engine has the oil injection still operational, then yes, you simply add fuel to the tank and make sure the oil resevoir is 1/2 or more full of two stroke oil (with the TCS-III markings). If you are unsure of whether or not the system is still in place or operational or not, then the suggest test procedure is REQUIRED or you risk ruining the engine. Many folks disable the oil injection because they do not trust it. In that case you MUST pre-mix oil and fuel. The oil line from the resevoir must be disconnected and plugged at the engine and the alarm harness from the pump disconnected. The overheat warning will still work. Be sure you understand fully what condition this engine is in before you run it.