oil injection

steplift20 · #1 09-07-2009, 09:01 PM

ok went out today and filled my oil tank that is mounted on the engine and the alarm didnt go off so it was low and thats why it was beeping but when i got back after riding it for about 8 miles i took the cap off the engine mounted oil tank to see if it was to the top and it wasnt it was about 3/4 of an inch fron the top so i think that if i kept going the alarm would have went off again, why and what can i check its supposed to fill from the oil reserve tank and it is but its not staying at the top I removed the oil pickup tube with the screen on it and blew it out maybe there was a restriction any ideas would be welcomed thanks, dont know if that solved the problem yet and by the way fishing wasnt slow at sandy hook nj

THEFERMANATOR · #2 09-07-2009, 09:29 PM

What engine? Your saying it isn't filling the tank on the engine from the boats tank?

steplift20 · #3 09-08-2009, 06:40 PM

its a 1988 mercury out board 150 hp, its filling it from the resrve tank but i dont think its keeping it filled to the top

THEFERMANATOR · #4 09-08-2009, 10:17 PM

Have you tried to bleed out the lines to make sure you are getting oil from the main tank? There is a chance that your check valve going to the tank inside the boat is bad and not allowing pressure to build up and push the oil up to the engine. Also an air leak anywhwere in the tank inside of the boat will cause it to not pump oil up to the engine. Also the pick-up inside of the boats tank is famous for getting clogged, and also the foil that comes on 2 stroke oil bottles is known to get in the oil tank and plug the pick-up.

1. Check your pick-up in the tank inside the boat.
2. Fill the tank inside the boat and then remove the cowling from the engine. Loosen the cap on the engine mounted oil tank and start the engine up and see if oil gets pumped up to it. This is also how you are supposed to purge the air from the system. If you get oil then it is working, if you don't then move on to 3.
3. If you don't get oil at the engine mounted tank within a minute or two shut it off and immediately go to the tank mounted inside of the boat. Check to make sure it is holding pressure.
4. If no pressure check the tank and caps for torn o-ring's or anything that will let air leak out. If you do have pressure check the oil supply line for kinks or pinches where it would block off flow.
5. Take the oil tanks pick-up out that has the 2 hoses on it. Start the engine for a few seconds and check the cap to see if pressure is ccoming down from the outboard. If you get no pressure pulses inspect the hoise from where it hooks up at the engine to the tank for cracks or pinch's.
6. If the hose is good next take the hose off at the bottom of the engine and check the check valave for damage or blockages, Start the engine and see if you get pressure from it now. If you don't get pressure from it now and the valve looks fine then chances are your problem is pretty serious like a broken reed or something.

The MERC system is pretty simple in the fact that it uses crankcase pressure to pressurize the tank in the boat which in turn pushes oil up to the engine mounted tank where it gravity feeds down to the oil injection pump. But it's simplicity also can be it's downfall as a small air leak or a pinched or kinked hose will bring it down.

steplift20 · #5 09-21-2009, 06:53 PM

I removed the oil pick up tube from the main tank and blow out to clean it and everything seems to be ok now, i think the filter screen was dirty, I started the engine and losened the cap and oil pumped out of the tank so i know its getting pressure, thanks for the advise

FishThis · #6 09-21-2009, 09:18 PM

I have the same system on my Mariner 175 and she smokes quite a bit at idle and start up. How do you know if it is metering the correct amount of oil, and if so how can you adjust it......

spareparts · #7 09-21-2009, 09:49 PM

go ahead and replace the screen on the pickup in the tank, they aren't that expensive, but I've seen a couple stop up, I cleaned them with solvent, treid them again, and they still stopped up. Felt like it had some kind of goo on it, Never did figure out where the goo came from(maybe some bad oil at one time?), I cleaned the tank, just a little crap in it, but it didn't solve the problem till I replaced the pick up

phatdaddy · #8 09-22-2009, 06:26 PM

fish this,i just checked mine last week.
the 2.0 should pump 6.8 cc +/- 10% in 3 minutes @ 1500 rpm
the 2.4 should pump 8.2 cc +/- 10% in 3 minutes @ 1500 rpm

remove the clear hose where it goes into the fuel tee . you must block off the tee to prevent fuel from leaking. catch the oil in small container and measure.
( i used the small cup that comes with cough syrup)
MAKE SURE YOUR FUEL SOURCE IS PRE-MIXED WHEN PERFORMING THIS TEST.

FishThis · #9 09-22-2009, 08:09 PM

Thanks for the info... Now the my carbs are right I should make sure my mixture is too.....

MATT

phatdaddy · #10 09-22-2009, 09:33 PM

l got this info from a merc manual for a v-135 thru v-175 serial #'s C221500 & up. if yours is different, you might want to verify the amounts...........