'97 Mercury 150 EFI 2 stroke loss of power

[rebelroy11]

I bought this boat in July of '13. The previous owner put a brand new fuel pump in. I actually bought it the day it came out of the shop. Boat ran great everytime out. About Sept was the last time I took it out until this past Saturday. So around 3 months. I do use stabil. I changed the lower unit oil and ran it on earmuffs and it idled. So I took it to the lake. It started up and as soon as I was able to open it up I took off. I notice I was missing some "get-up" so I checked under the pedal to make sure nothing was blocking it but it was free. I had it to the floor. RPMs were around 2300. My speedo doesnt work but I know I wasnt doing over 10mph. Engine sounded fine but just no power. After running it for a while did begin to have slight idling problems and would die occasionally when I slipped it in FWD gear. I have not changed the filter or plugs since purchasing the boat and no idea how long ago they were placed. Being I'm not an outboard mechanic, this will be the first thing I change along with maybe some injector cleaner. The engine lacks that "rev" when I get on it. It just slowly creeps up just to the point where the nose will rise a little and thats at full throttle. In my limited knowledge it sounds like its not getting enough fuel. Any ideas?

 

[1nebel0]

Re: '97 Mercury 150 EFI 2 stroke loss of power

First thing to check is compression...wasting your time if you skip this step... Next would be a fuel pressure check on the rail to insure 39psi. Is there an air leak in the system? Does the bulb stay hard or go soft? Checking spark on all 6 cyclinders as you could have a couple not firing... When was the last time injectors were sent out to be serviced and clean(Brucato is the best)..As you can see, many different tests need to be done to eliminate a spark, fuel or compression issue...let us know.....

 

[rebelroy11]

Re: '97 Mercury 150 EFI 2 stroke loss of power

First thing to check is compression...wasting your time if you skip this step... Next would be a fuel pressure check on the rail to insure 39psi. Is there an air leak in the system? Does the bulb stay hard or go soft? Checking spark on all 6 cyclinders as you could have a couple not firing... When was the last time injectors were sent out to be serviced and clean(Brucato is the best)..As you can see, many different tests need to be done to eliminate a spark, fuel or compression issue...let us know.....

I borrowed a compression tester from a friend so I will get that done this week when I get a chance between remodeling the house and the crazy weather we've had. Now that I think about it the bulb didnt pump up as tight as it usually does but if it doesnt start I usually just give it a few pumps and then try again until it starts. But it didnt go soft after running it for sure. I dont know anything about the injectors as it is a used boat. Thanks for the reply.

 

[rebelroy11]

Re: '97 Mercury 150 EFI 2 stroke loss of power

After tinkering with it I've found that compression is good and after doing a spark test, I've lost spark on 3 cylinders. Cylinders on both banks. Some people are now saying its the stator and others are saying its the power packs. Maybe coils. One "mechanic" that I work with is willing to bet his check its the power pack. He has a shop but he's more mechanical than electrical and doesnt have a way to test it. He also claimed that the stator was ONLY to charge your battery as opposed to what I've is that its for that and the ignition system. I have noticed some leakage coming from the stator but that was after I took the boat out a 2nd time. It didnt do that the first time out so maybe running it a lot with it running like crap just taxed the stator and caused it to get hot and melt the wax a little. Maybe its fine. Maybe not. No friggin idea...

 

[1nebel0]

Re: '97 Mercury 150 EFI 2 stroke loss of power

My guess was exactly your find...you are running on 3 cylinders.. in they were all on one side I would say switch box as it is a common Merc problem....There are tests for the stator as buying a new stator will set you back some $250-$350 dollars.. The stator is an important part that sends signals to the switch boxes... My guess will be a stator but you need to test..Coils almost never go out and not 3 at one time....

 

[Faztbullet]

Re: '97 Mercury 150 EFI 2 stroke loss of power

Swap thr red/blue stator leads on switchboxes, if problem switches sides its a stator,if not its a switchbox and replace both of them..

 

[1nebel0]

Re: '97 Mercury 150 EFI 2 stroke loss of power

Take it from Faztbullett- He is a certified mechanic that know his stuff..........