2003 Evinrude 225 HO slowly lost power

[Choffman2]

I was fishing a tournament this weekend on Amistad and noticed my boat was not running quite tip top but didnt think much of it as the wind was blowing 35+ so I wasn’t really pushing it hard enough to notice how off it was on day 1. Day 2 came and I noticed it pretty quickly in the morning, it seemed to run and idle ok, got on plane decent but a little slow but was only turning about 5800 rpm WOT and wouldn’t run past 62mph which is about 10 slower than it’ll run at cruising speed. We ran about 20-25 miles on day 2 when it really started to get bad. We were running WOT and i noticed this time it wouldnt get past 60 and just as i noticed that it slowly started to just lose speed, about a minute later it was running 55, then it got all the way down to about 48 and I shut it down. I knew something was up so I cranked it back up and it sounded a little funny almost like there was a bit of a miss but not quite, my partner couldnt even really hear it at first. When I cranked it back up I tired to get on plane and after about 5 seconds it still wouldn’t plane so I shut it down again and we ended up trolling back to the ramp. I called my mechanic but hes 4 hours from where I live and the only mechanic I can find that knows anything about these motors and willing to work on them. He suggested doing a compression test and fuel pressure test which I am going to try and do in the next couple of days but I am wondering if this issue is anything that sounds familiar to anyone who knows the engines. I have had a few fuel and oil issues with this boat since I have had it. I thought it was really strange that there was no lights and no alarms ever to go off the whole time and I know my low oil alarm works cause it went off last trip. What would cause a motor to slowly lose power in this fashion? Model #E225FHLSTA

[mactlman]

injector going bad will cause this would not use until hooked up for a diagnosis

[Danrude]

If your boat has a two fuel tank setup the valve that switches between them can go bad. When the valve fails it will restrict the fuel flow from one of the tanks!

[Choffman2]

I was just hoping it isn’t a scored cylinder or something drastic like that, I guess we will find out when I can get it to my mechanic only issue is he is halfway across Texas. It just worried me that it may be something major since there was no beeps or alarms at all. And I do not believe my boat has 2 tanks I believe its a single 50 Gal tank its a 2003 stratos 201 pro xl.

[Choffman2]

It may be worth noting that I did notice the motor doing a little surging for the few trips at idle before this happened. It wasn’t anything major just kind of surged every couple seconds but still ran perfectly fine and would run in the 70s cruising without issue. Not sure if that’s something someone may have experience with or not just figured id throw it in there.

[ChampioNman]

Pull the plugs and inspect them for wear if it has been a while since they've been replaced that could be your issue while the plugs are out run by one of the auto parts stores and rent a compression tester and check that not hard to do.

[Rude520]

You could run to a local parts store and grab a compression gauge. If you don't want to buy it most stores have it in their loan a tool fleet. IF the compression checks ok a couple of small things that could be checked:

1) Pull the engine cover and breather so the throttle bodies are exposed. The bottom two are connected with a rubber hose. Age can cause them to get hard and brittle and not open the butterflys. You can check this (with engine off) by opening the throttle wide open and make sure they are all opening the same. You can try to turn the hose on the linkage as well. When mine did it the engine vibration at speed would slowly close #5.

2) Since you have the engine cover and breather already off hook the hose up and start the engine. Place your hand over each throttle body while at idle. They should all suck you hand to it. If one is blowing you have a bad reed or reed gasket.

I've had both of those happen. They cause similar (but not exactly) issues.

I agree with mac though. Even if you find something on these two I would want it checked before running on the laptop. The software is priceless.

[Choffman2]

Haven’t had any time at all to really dig into this issue yet but I did notice yesterday when looking at the prop that it was completely covered in black soot, which is new and has never happened before. My guess is this is caused by running too rich and would lead me to believe this could be some sort of fuel issue, one thing I did check when I had the boat running the last time was pumping the primer bulb while running and it never seemed to get hard and I could continuously pump it. It may be a while before I have to time to drive to Belton to drop it off to my mechanic so I am gonna keep trying to test things I can on my own for now until then.