Oil injection issue

[Texas66]

I have a 240 Merc on an Islandia with a recurring problem. The small oil reservoir mounted on the port side of the engine apparently feeds via suction from the main 3 gallon oil reservoir. The engine mounted reservoir has an alarm which sounds when the level gets low. About 6 engine time hours ago, the small reservoir just stopped siphoning from the main tank setting off the dash alarm after about 20 minutes of run time (after I top it off manually). Any ideas on why the problem suddenly occured after many hours of trouble free cruising? It's getting old stopping every 20 minutes to top off the oil on a hot engine.

 

[JPX]

Oil pump might be failing to draw the correct pressure? Filter clogged?
Cracked or split oil hose that is sucking in air and reducing oil feed efficiency?

Oh and check the check valve on the top of the tank. It may not be relieving pressure from the tank properly and causing the oil starvation.

 

[Texas66]

oil density

Thanks. I think there is something going on with vacuum, blockage or the oil cap you mentioned. Are there any operational differences in oil flow properties I should be concerned with? Are some 2-cycle marine oils thicker than others?

 

[seadoosnipe]

2 cycle oils!

The only difference in 2 cycle oil is whether it's synthetic or the standard petroleum based type. What changes in the properities of the oil is it's mix ratio. 50/1, 40/1 or 32/1..........
I'm not sure it applies to your situation, but in my Rotax 787, I changed out an oil line and had to go through the procedure of venting (purging) all the air out of my injection pump and lines.
This may or may not apply to your type engine.

 

[wingnut1961]

Did you switch oil brands/type? I've heard some will coagulate when mixed, plugging lines...

 

[kustomkarl]

Never Mix different brands of oil. Especially Mineral and Synthetic oil. It will ruin the engine. I would stick with the same oil the previous used or you 'll have to drain and flush the entire oil line system, from tank to injectors ends in the carbs.

Karl

 

[legojones]

Never Mix different brands of oil. Especially Mineral and Synthetic oil. It will ruin the engine. I would stick with the same oil the previous used or you 'll have to drain and flush the entire oil line system, from tank to injectors ends in the carbs.

Karl

Really?

I just bought a 2003 Utopia with 250 Optimax. I have no idea what brand or kind of oil the previous owner used. Is there someway to tell?

The oil tank is almost full and I would hate to have try to drain it all.

 

[kustomkarl]

Here is the specifics on the oil;

Use High quality low ASH API TC Injector oil.
Do Not use NMMA TC-W, TC-W2 or TC-W3 outboard motor oils or other ash less type 2 cycle oil. Avoid mixing different brands of API TC oil as resulting chemical reaction will cause severe engine damage. Never mix Mineral or synthetics oil together.

Never use fuel containing more than 10 % alcohol,( Methanol or Ethanol) as severe damage will occur. The minimum of 87 octane is recommended for most engines.

I would ask the previous owner if possible exactly what he used...

Karl