1994 150HP 2.5 XRi EFI possible stator problem?

I just bought a '94 ProCraft V180C and took it out for the first time. Everything ran great for about 1.5 hours from idle to WOT. Stopped for lunch and fishing for about a half hour. Started right up with no problems and ran fine until I would go WOT. After a few seconds the motor would die down (lose power) as if struggling for fuel, and if I backed out of the throttle the motor would run well without any skipping, misfires, etc. The problem would only reappear if I went WOT. I wasn't paying attention to the tach at the time of the problem so I can't say what the rpm's were, but it seemed the motor would run up to 40mph without a problem. The previous owner had tuneup work done last June and never used the boat after that, so the plugs, fuel filters, etc. had 0 hours to them prior to my trip. Only new fuel and oil used. I've done lots of auto work, engine rebuilds, tranny swaps, etc., but am new to the marine world and had to do very little ignition/electrical work asside from swapping out starters and alternators. I bought a SELOC manual for the motor but it's not very clear regarding the ignition system. Any recommendations for learning more about the outboard ignition system on this motor (videos and such)? I usually learn something one of two ways; I either mess up a couple times before I get it right or I learn watching someone else do it right the first time and the stator seems too expensive to learn a lesson by messing up without a thorough troubleshooting.

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

Ck the filters and fuel delivery system

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

Most likely a fuel delivery problem. However, if you don't find your problem is caused by the fuel deliver system and want to troubleshoot the ignition system, these are my comments...

I have the Seloc, Clymer, and Mercury shop manuals for my 1996 150HP carbed Mercury outboard. It may seem like overkill but as a newbie to 2-stroke outboards, I found it very helpfull to have multiple descriptions/photos/drawings for a particular task. I think that every one of these manuals is OK for troubleshooting the electrical system, although the Mercury shop manual is the best one. You will need a multimeter and also a DVA meter (about $100) to do most of the ignition tests prescribed by the manuals.

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

It will be two weekends before I can get back on the water, but I squeezed the primer bulb this morning before I left to work and it still had pressure this afternoon at lunch (don't know if that proves much). I depressurized the fuel sytem and checked both fuel filters and they look very clean if not brand new. I did a quick visual inspection of the wiring just to see if any connections had worked themselves loose had any carbon etc., but again everything looks very clean and well maintained. The only problem I found was the "up" tilt wire to the tilt switch on the engine had worked itself a little loose from it's connector. Anything else I can do to test the fuel system with muffs? Just an FYI, before I depressurized the fuel system the engine would start instantaneously without even pressurizing the bulb. Because of that I sometimes forget to do it before I start the motor. Is that a bad thing?

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

Thanks for the info:
I am Mr. Overkill when it comes to manuals and such so don't feel bad. I think I have at least one service manual in each of my bathrooms at home. Good time to catch up on some reading when you can't go anywhere. Anyway I have a Craftman multimeter and I think it has a connector for a DVM adaptor, but I love tools so maybe I can pick up a Fluke unit (or another if anyone has a recommendation and while your at it a recommendation for a compression tester). Someone has to have made a video showing how to do this type of work. Maybe I'll start making videos of me doing my repairs with my digital camera, at least then people can watch me make all the mistakes before they do.

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

The symptoms you're describing act like a partially clogged fuel filter. I fought that fight all last summer, and finally pinned it down by installing a fuel pressure meter. Would run fine till wot, then dive to zero. The thumb sized merc fuel filter wasn't obviously plugged but changing it would restore the pressure.

At season's end I drained and ran all ten gallons of remaining fuel through a scientific grade filter and found a little bit of white snot, aparently a result of alcohol in the fuel and water, and maybe bacteria.

I will clean out the whole system, and install a water seperating filter before I run it this year. The thumb sized mercury filter has a new home.

Mine is a 1988 XR4 carb motor, but the principle's the same. Failure of the fuel system to keep up at WOT will lean it out and make it slow down, if you're lucky, or just lean it out enough to burn up if Murphy prevails.

hope it helps
John

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

OK, starting over. I take back what I said about the SELOC manual. I found a great deal of information in regards to the ignition system. The lay out of that portion of the book was a little confusing, but I think I found enough information to keep me busy for a while. I have a new concern now. Section 5-16 of the SELOC manual #1416 "Troubleshooting Battery CD Ignitions" states "Do not use a maintenance free battery with these types of ignitions as they tend to overcharge and blow the packs." Is this true? Should I get different batteries? The primary and backup starting (not trolling)batteries I currently have in the boat are maintenance free batteries bought from Bass Pro Shops by the previous owner.

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

IMHO you should follow the Seloc manual's warning and use a marine battery only. There are several reasons for this, including the one mentioned in your quote from the Seloc manual. If you want more information on the other reasons, you can search this forum and/or google the internet to learn more about the differences between marine batteries and automotive batteries.

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

Just wanted to throw this out. I had a 90hp Johnson that was displaying the same symptoms. I too thought it was fuel related but later found out that it was the power pack. I guess Mercury calls it the switch box? I just think it would be an ignition issue. Just my 2 cents

Re: 1994 150HP 2.5 XRi EFI possible stator problem?

Thanks for everyone's input. I'll follow up with my results as soon as I solve the problem. It might not be for two weeks, but I'll make a little case study out of this thing and try to document the steps I take to solve the problem with pictures and maybe some video that I can post online so others with similar problems can see what was done to fix the problem. Reading through my SELOC manual has raised another question about what octane fuel to run, but I'll save that for another forum topic.