Engine issues - any help?

[Hannibal]

It's an Evinrude 225 (2006). While running around on the river this weekend, I noticed a couple things that concerned me. Last week, running at WOT (about 4500 rpm), the boat would run about 42-44mph. On Saturday, 4500 rpm saw me running around 35-37 mph. Water conditions were fairly the same.

What really had me concern was a sense that the boat was surging. Almost like the prop was coming out of the water (you'd hear a slight audible tone). Due to that, I kept playing with the trim to see if that would improve things. Note - the trim guage does not work (several things are a work in progress - it's a 1991 2110 WA). Adjusting the trim didn't seem to make much difference.

Being that I was heading away from where I put in, I decided to turn around and do any troubleshooting "close to home" rather than way up river. After turning around, things were still not right and I felt getting worse. My wife suggested I cut the boat off as it maybe overheating (no temp guage).

I did so - let it sit for 5 minutes and then tried to start her back up. Nothing. It would crank but not turn over. It almost sounded like I had no gas or even bad gas in the tank (fresh gas was put in two weeks ago and the tank was still 1/2 full).

I kept trying to start it with the same problem so I eventually called my buddy for a tow back to the dock.

After 20 minutes or so, another friend came by and suggested locking it in neutral and then starting it up and revving the motor - perhaps in an attempt to "flush" any thing out. It seemed to work. It cut off at first but the second time, as long as I kept the rpms up, it worked. By doing that a few times, I was able to get into low rpm neutral and not cut off.

I started to limp home and progressively built up speed as I went to see how things were going. On the way back, it didn't seem like the engine was surging anymore. Power wasn't there like before (weight between the two trips was relatively similar) but I am not sure a difference of 5-8 mph can be "normal" depending on other variables.

One thing that was noticed on the way home (didn't notice on the way out - could have been there) was that the motor was "rooster-tailing". There was a stream of water shooting up and back - almost like you see on certain wave runners. I am 99% certain this wasn't the case last week (which was my first time out).

Is it possible that a hose popped lose? I didn't see anything immediately when looking over the boat Sunday morning.

Could it have been a water tube meant to push fresh water through the motor? That could have caused the engine to overheat creating the problems I was having .............

Any thoughts? I am going to pull the boat out of the water this week and give it a once over but I am new to boat motors (particularly OB engines) so I am not sure what to look for outside of a hose end with no home.

Thanks in advance.

 

[Jtwo]

Hannibal,

Couple of quick thoughts reading your post.
1. RE: 4500 WOT - Most motors recommend a target RPM of 5000-6000 with 5200 to 5600 being a good norm. 4500 at WOT sounds like you're running a prop that might be 'not optimum'.
2. RE: Surging - I have several motors that I deal with regularly (Honda and Yam). This 'surging' etc. is SOSDM (Same ol ____, different motor). While it does sound like a 'fuel' issue, that has a broad field of 'solutions'. Run some injector cleaner and add some stabilizer to fuel (you don't know what might be lurking in the tank, regardless of how fresh the fuel is). Hope that does the trick.
3. RE: #2 'clogging things' - we clogged an injector (we theorize) on a trial run, which leaned out the cylinder (#1) , that ran hot and melted the rings/piston. WE did 15 minutes at 3500, and 60 seconds at WOT. Bamm! Do not pass 'GO', go directly to 'new powerhead' and pay $$$s. Lesson learned - If you think the engine is running poorly, be patient and avoid WOT. Use a small portable tank with the cleaner in it to get faster results on that front. Inspect your primary fuel filter. When you change it, pour the contents into a glass jar. let is sit for an hour or so. if there is junk in the tank, you'll see the evidence in the jar.
4. RE: Speed difference - Check the transom. Make sure everything is still attached, etc. Could you have picked up a plastic bag on the low speed run? Is the prop dinged or tweeked somehow? Any transome mount ducers hanging down?, Trim tabs stuck or bent? Evidence of strike damage? Bow Lines in the water? Might be worth diving on the bottom to check that too and remove any possibility there.
5. RE : column of water - If it is a small single column, like a jet ski, could be some water supply. The freash water flush though would likely be a burble - rather than a stream. Don't know how the motor is hung (transom or bracket). Again, look over the back (carefully) while running to see where it is coming from. If from the water, you have something on the hull messing with the water flow. If off the engine, you have a loose hose. We have a 2520 and it has twin 200s on a bracket. The stb motor has a column of water (like a wide hose spray) that shoots up the outboard side. We think it is water coming off the bottom just inboard of a trim tab and shooting up 2' after it leaves the bottom of the boat - next to the engine.
6. If you had a heat issue, it will probably code the engine. A good mechanic can hook computer to it and read that. however, a heat issue will usually shut the engine down to safe mode (2000ish rpm) or off. You shut yours down - so probably not a heat issue. ALWAYS check for the little cooling water stream when starting and running. Here in So Cal the danger is getting a kelp leaf (about the size of a paper towel) wrapped on the lower unit where the water intake is - no water = heat = shut down.

Bottom line - check your lower unit, prop, bottom and transom for strike damage, lose stuff, clogs, etc.

Run fuel cleaner.

Investigate prop size.

Get to know a good mechanic....

Cheer

Jtwo