2004 Johnson 90 HP

[mmarino]

Two questions. Regardless of the type of oil I use, my engine is running way too rich. I've used standard 2 cycle and partial synthetic, several brands. Is there any way to adjust the oil that is automatically delivered from the oil tank? If so, how do I go about it?
The other question is which type of oil should I be running in it? Motor runs well, just real smokey.

 

[wilde1j]

Re: 2004 Johnson 90 HP

Have you done anything to check oil consumption and ratio to gas? It may not be over oiling, but a too rich gas mixture, which can have a variety of causes.

It's easy to check oil ratio. Put a mark at the oil level on the oil tank, fill gas tank. Use a decent amount of gas (20 to 30 gallons), fill the gas tank and note quantity. Fill oil tank back to the mark you made earlier with measured amount of oil. Divide gas by oil in same units. Should be ~ 50:1.

 

[mmarino]

Re: 2004 Johnson 90 HP

I live in Las Vegas. Elevationa bout 2500 feet. Had a local shop rebuild the carbs. Tested the motor out at Sea Level, but not back in Vegas. Don't know if this would have a bearing on it or not. Never checked oil consumption, but I will. If I find it is consuming too much, what would my next step be? Thanks.

 

[wilde1j]

Re: 2004 Johnson 90 HP

Altitude will cause the engine to run richer, unless the shop that rebuilt the carbs used smaller jets. Typically, I don't think 2500' MSL is high enough to rejet, though. BTW, were carbs rebuilt at sea level?

If you are using excess oil, there are a number of possibilities, one being entrained air in the gas side. This makes it appear to the pump that more fuel is being used than really is. Typically can be any source of air leak from the pickup tube in the tank (cracked), a cracked hose, leaking connection, etc. A remote possibility is a problem with the OMS pump, but this is rare.

 

[mmarino]

Re: 2004 Johnson 90 HP

JIm, carbs were rebuilt at Las Vegas elevation. No mention of rejetting different from what was in there. Almost sure if they used new jets, they are the same. I'll start checking around for cracks, leaks, etc. Is it best to do the checking with the motor running, idling, fast throttle? Is the cracked house you referred to the top black plastic cover on the oil tank? Thanks a lot for your timely help. I'm getting the knowledge I need. Appreciate it.

 

[wilde1j]

Re: 2004 Johnson 90 HP

Nah, I meant HOSE. Motor doesn't need to be running, Visual inspection.