How do I adjust Oil injector on 90HP Mainer?

[Jerry900]

The plugs on my 1987 90HP Mariner are sometimes getting fowled with oil. The fowling is not fixed by running WOT. I checked the setting of my fuel injector and can't figure out how to adjust it. My "Mariner Outboards 1977-89 Repair Manual" by Soloc says to align the mark on the oil injection arm to the mark on the pump case in the idle position. There are two marks on the oil injection arm. So I thought one might be for idle and one for WOT. I adjusted to line up the closest mark but this took 3 turns on the linkage in the direction of more throttle. That seemed like it was in the wrong direction and just seemed to make the problem worse. So, I adjusted the other mark to line up at WOT witch seemed to be in the right direction. I haven't run the engine yet. I thought I better check with the experts before I go any farther. How am I supposed to adjust this? Any help will be appreciated.

 

[sschefer]

Re: How do I adjust Oil injector on 90HP Mainer?

As per your manual you adjust to the first mark and disregard the second. However, like you I was befuddled trying to figure out which one is the first mark. You have it right now. You should barely have to adjust the linkage when the throttle is at the stopped position.

However these pumps have been known to over pump when they are failing. If you are having problems like you say, then mix up some 50:1 fuel in a gas can and put your fuel line in the can so you can run the engine with lubricated fuel. Then disconnect the oil pump hose and start the engine. The Seloc manual has the numbers for oil output at idle in a given period of time. Use a graduated cylinder to measure the output and either adjust the pump accordingly or replace it.

Personally, I'd pull oil injection off and pre-mix instead.

 

[Faztbullet]

Re: How do I adjust Oil injector on 90HP Mainer?

Set the pump alignment marks as manual states and check pump output as suggested. I myself have never seen this design of pump "overpump" as it is gear driven but have seen the rear seals blow out and cause over oiling of lower cylinders. If all 3 plugs are fouling i would look more toward the t-stat hung open and engine running to cool or engine not running in correct rpm range(lugging) by overpropping.

 

[Jerry900]

Re: How do I adjust Oil injector on 90HP Mainer?

Thank you for your inputs.

Sschefer, I?ll try to define the marks so I can be sure what you are saying. If the throttle is at idle both marks on the oil injection arm are on one side of the mark on the pump case. As the throttle is increased one mark lines up. Call that mark A. When the throttle is increased more, the other mark lines up. Call that one B.

The last adjustment I made before I wrote my question was to line up mark B at WOT. When I returned the throttle to idle, mark A was a long way from lining up. It took 7 turns on the linkage to line it up. That doesn?t seem to fit your statement that ?You should barely have to adjust the linkage when the throttle is at the stopped position?.

With mark B lined up at WOT, the plugs looked clean after I ran it for a while. But I wonder if it is getting enough oil when adjusted that way. I haven?t checked the pump output yet.

Faztbullet, When I followed the manual using mark A, the plugs fowled again in a few minutes. I think following the manual using mark B would give it even more oil because the pump is supposed to give a 100:1 mixture at idle and a 50:1 mixture at WOT.

Since these pumps have "been known to over pump when they are failing" maybe that is what is happening. I think I?ll take it down to my dealer and let their mechanic check it out.

 

[Jerry900]

Re: How do I adjust Oil injector on 90HP Mainer?

The mechanic (Kip) at Tom's outboard repair adjusted the carberator and said that the oil was fine. I ran it the next day and it worked fine.