Mixing not working? Thinking of converting to premix. '95 75ELPTO

[Boatin_in_KY]

Hello, so I have a '95 75HP two stroke auto mix. I haven't been able to get it to run correctly. New impeller, plugs and fuel filter. Cleaned the oil tank. Fresh gas in an external tank. It will sometimes start and run for a few seconds (and smoke) but then die. I pulled the carbs and took them apart over the weekend and found a lot of oil in the bowls. I'm thinking its sucking too much oil, and not getting enough gas. The tank has the vent open, and holds pressure in the bulb. I do plan to also check some of the fuel lines. At this point I'm thinking of just switching to premix and seeing what happens. Anything else I should check? Is heavy oil concentration in the bowl normal? Also, any special precautions I need to take when reinstalling the carbs?

 

[batman99]

I switched my 1995 OMC engine to pre-mix (50:1) three years ago and never regretted it. IMO, if its getting gas, then its getter proper amount of oil. Oil mixture that I control. LOL.

As a test for your engine, simply by-pass the oil side of your VRO system. re: Disconnect alarm wires, disconnect oil side pump wire, plug oil intake line and go pre-mix with external 5 gallon tank (with 50:1 premix). If your engine runs better on pre-mix, simply connect gas line to internal gas tank and run pre-mix in it. Only takes a few steps to test it (for a day or so).

 

[Boatin_in_KY]

Good point. I'll see if I can try it this weekend.

 

[flyingscott]

I switched my 1995 OMC engine to pre-mix (50:1) three years ago and never regretted it. IMO, if its getting gas, then its getter proper amount of oil. Oil mixture that I control. LOL.

As a test for your engine, simply by-pass the oil side of your VRO system. re: Disconnect alarm wires, disconnect oil side pump wire, plug oil intake line and go pre-mix with external 5 gallon tank (with 50:1 premix). If your engine runs better on pre-mix, simply connect gas line to internal gas tank and run pre-mix in it. Only takes a few steps to test it (for a day or so).

Absolutely none of this information pertains to a mercury oil injection system keep it in the OMC section. The VRO system is OMC/BRP specific nothing to do with mercury.

That being said, I would find out why you only have oil and no fuel in the carbs sounds like more of an issue on the fuel side of things.
Is the fuel pump in good condition?
Are all the fuel lines in good condition?
Do you have good spark on all cylinders?
Do you have good compression?

I had that motor and as i recall the oil pump actually pumps oil into the fuel pump to be mixed, if you only have oil in the carbs seems like that is working.

 

[batman99]

Absolutely none of this information pertains to a mercury oil injection system keep it in the OMC section. The VRO system is OMC/BRP specific nothing to do with mercury.

That being said, I would find out why you only have oil and no fuel in the carbs sounds like more of an issue on the fuel side of things.
Is the fuel pump in good condition?
Are all the fuel lines in good condition?
Do you have good spark on all cylinders?
Do you have good compression?

I had that motor and as i recall the oil pump actually pumps oil into the fuel pump to be mixed, if you only have oil in the carbs seems like that is working.

Sorry. My bad!

 

[flyingscott]

Good point. I'll see if I can try it this weekend.

You cannot follow what batman said because you have none of that on your motor.

 

[Boatin_in_KY]

You cannot follow what batman said because you have none of that on your motor.

I can still bypass the oil hose though, right?
Obviously it isn't VRO though.

Is there any easy way to check the fuel pump? I do have compression, but I haven't checked spark. Fuel lines look ok, and I spot checked the ones on either side of the fuel filter when I changed it.

I'll have to do some more looking regarding the fuel pump and where the oil actually gets injected.

 

[flyingscott]

It's a little involved disconnecting the oil injection on that motor but straight forward and easy. Best way is to get a manual.

 

[g0nef1sshn]

Got my 92 40 hp with the bypass already done. I premixed 50:1 and the first test run ran fine. I cant help with the steps of the bypass procedure though.

 

[Boatin_in_KY]

Recommendations for a manual or where to get one?

 

[flyingscott]

Mercury manual only best places to get it are ebay or the dealer.