MOTOR PROBLEM! MERCURY 150 XR6

[gunnarreeves]

Well today my warning alarm went off again. The first time it happened i was running 45mph @ around 4200 rpm and got a quick "beep-beep" out of my warning buzzer. I immediately reduced throttle and came off pad, shut the engine off, turned my key back to the on position, the usual "pre-start alarm" sounded and i cranked it back up and ran all the way in without another problem. It happened again today at the same speed but i only got one quick "beep" lasting no more than a second so i didn't reduce throttle and kept running my way in to the boat ramp. This buzzers sounded both times after about 10 minutes of running at a constant 40-45mph and 4000-5000 rpm.

here is what i know:
1) No water pressure gauge but stream is steady both at idle and while running at all rpm/speed ranges
2) Oil reservoir and oil tank on the motor itself are both full
3) Motor is idling fine and no hitch when throttle is increased, so i don't think it's my fuel pump(s). Not sure if i have just one or a high and low pressure fuel pump
4) Dealership replaced impeller when i bought the boat two months ago and i checked all the water intakes for obstructions and didn't find any

My dealer suggested that the oil pump might be trying to go out and that i should run both Oil Injection like normal and 16oz:12gal fuel premix for insurance purposes because i sure don't want to burn my motor up, i don't have the money to replace her lol. I would just like to know what some of you expert mechanics thought about this. I read in my Merc manual and everything to do with those alarms pointed back to the Oil Injection system. If i have to replace my oil pump, is this something i can do on my own and how much will this cost me?
Thanks, Gunnar

[RiverRatMD]

First of all, make sure the oil tank under the hood is "FULL TO THE TOP" even just a tiny, fraction, sliver low can cause that alarm to go off. Make sure no bleed lines are off, loose, or leaking. Ok - so it's a bee-beep? Not at all a solid beeeeeeeeeeeeeeeep, right?! Solid=overheat. Multiple beeps=likely oil related. The XR6 oil system's are usually absolutely flawless. When I say Full to the top....literally, to the top with NO gap on the under cowl tank. I mean a 1/4" gap will set some of those things off. Make sure the caps are tight (but do not overtighten them) . I believe in the oil injection system. Post your concerns on the mercury engines forum. Don is very helpful and may have more suggestions for you.

[gunnarreeves]

Thanks RiverRat. It is a bee-beep not solid and it doesn't last long, like a second tops. Now that you say something about the tank under the cowl being low, i don't think that it is full to the top. There was a gap when i pulled the cap to check. I definitely don't want to go to premix, i hate doing all that. I wonder what would cause there to be a gap in the tank under the cowl though???

[RiverRatMD]

Thanks RiverRat. It is a bee-beep not solid and it doesn't last long, like a second tops. Now that you say something about the tank under the cowl being low, i don't think that it is full to the top. There was a gap when i pulled the cap to check. I definitely don't want to go to premix, i hate doing all that. I wonder what would cause there to be a gap in the tank under the cowl though???

Take the cap off and fill it to the very top. Then carefully re-install the cap and tighten snuggly. Make sure that there's no leak on any oil lines. The tank under the cowl will get low over time for a variety of reasons such as a leakage at any of the oil tank caps or just sitting for awhile. First get it completely 100% full, and fill the reservoir tank in the boat (again, a good seal at the cap(s) is a must). Then, take it out, see if the alarm is gone. I hope this is all it is. Those sensors are very touchy.

[gunnarreeves]

Thank you for the tip. I'm going to fill both the tanks and tighten the caps. I made marks on both tanks to see if they drop any and I'll check everything before i run the boat tomorrow then I'll let you know

[RiverRatMD]

Thank you for the tip. I'm going to fill both the tanks and tighten the caps. I made marks on both tanks to see if they drop any and I'll check everything before i run the boat tomorrow then I'll let you know

Good luck Gunnar. One last thing: You can fill the tank under the cowl (engine tank) by physically filling it by hand. OR you can do it with water supplied by rabbit ears while the engine is running. This is good because it will purge ALL the air out. It goes like this: Trim engine level, start engine, loosen the cap on the Engine oil tank and allow the level to rise until it seeps out the cap then tighten the cap. Either way will work, but the second way will get ALL possible air out.


BTW: Before heavy use in 2013 I would recommend doing some critical maintenance items if you haven't already done them.


* Change the impellor in the water pump and inspect the housing. (i do mine every spring)

* Change the lower unit oil (i do mine twice a year. one in March, one in August)

* Chance the plugs with the correct plugs called for by Mercury

* Lubricate all zerk fittings on the engine (steering and swivel bracket)

* Make sure your fuel lines are the EPA-approved lines. ANY grey line with orange or red writing is BAD -replace!!
AND they sould be done from the Tank all the way to the engine if needed


* Always use quickleen in every tank. And it's wise to use quikcare or star-tron also.

* remove center of the rub rail all around the transom and make sure the screws holding the top cap to the hull are tight. This is very wise to do at least once a year Gunnar.


Good luck brother

[Reedbassn]

Well today my warning alarm went off again. The first time it happened i was running 45mph @ around 4200 rpm and got a quick "beep-beep" out of my warning buzzer. I immediately reduced throttle and came off pad, shut the engine off, turned my key back to the on position, the usual "pre-start alarm" sounded and i cranked it back up and ran all the way in without another problem. It happened again today at the same speed but i only got one quick "beep" lasting no more than a second so i didn't reduce throttle and kept running my way in to the boat ramp. This buzzers sounded both times after about 10 minutes of running at a constant 40-45mph and 4000-5000 rpm.

here is what i know:
1) No water pressure gauge but stream is steady both at idle and while running at all rpm/speed ranges
2) Oil reservoir and oil tank on the motor itself are both full
3) Motor is idling fine and no hitch when throttle is increased, so i don't think it's my fuel pump(s). Not sure if i have just one or a high and low pressure fuel pump
4) Dealership replaced impeller when i bought the boat two months ago and i checked all the water intakes for obstructions and didn't find any

My dealer suggested that the oil pump might be trying to go out and that i should run both Oil Injection like normal and 16oz:12gal fuel premix for insurance purposes because i sure don't want to burn my motor up, i don't have the money to replace her lol. I would just like to know what some of you expert mechanics thought about this. I read in my Merc manual and everything to do with those alarms pointed back to the Oil Injection system. If i have to replace my oil pump, is this something i can do on my own and how much will this cost me?
Thanks, Gunnar

I would add that you should post this on the BBC Mercury Outboard forum. There are some very good mechanics that give good advice there too. Not to say RiverRatMD did not give you excellent advise as well. Just suggesting you cover all bases. Good Luck

[maconart]

Make sure there is not a hairline crack on the cap of the oil reservoir. I had similar happening to me and found it. Under certain speeds the pressure/vacuum would open up the crack allowing enough air in to set the alarm off.

[RiverRatMD]

^^^ yup! this is common! gotta check!!! ^^^

[Have rod will travel]

i have a very similar problem. I put a multi meter and showed no continuity, which is good. My engine is 22 years old, I am wondering if the float is starting to go, and may be ok for a while and then send a message its not working. Reading this, I will add oil to the very top and then see what happens.