Merc. 225 EFI

jwclbi · #1 04-04-2010, 10:22 AM

I have a 1998 225efi merc that when it is running at idle or running at low speeds (800-1100) rpm's the engine will stumble/misfire, alarm will beep then continue to run fine. Seems as though it only does this when the engine is first running. After running and warm it doesn't do it. Anybody have any experience with this?

eggsuckindog · #2 04-04-2010, 05:01 PM

Check the on motor fuel filter for water - that could be the alarm maybe but your description almost sounds like a voltage issue. The motor thinks its been turned off and on, hence the alarm - does it sound like the original test sequence when you turn the key?

On another note - when mine starts that low 1-2K stumble I run some Evinrude Fuel System Cleaner on deposit removel ratio, clears it up in 1/2 hr running

jwclbi · #3 04-05-2010, 02:35 PM

Thanks for the info Egg, yes the beep is like the one when you first turn the key when system runs its test. It only beeps for a second. It does the same exact thing when the engine runs out of fuel. (which I have done, he he) I am going start with new plugs and filters now that we have some nice weather. Any other thoughts would be helpfull. Thanks

DonV · #4 04-05-2010, 08:07 PM

From experience......be sure the battery(s) are at full charge and have no troubles with low voltage, bad cells, etc. The computers on these engines are very picky about that. Seems they go into "protection" mode and meters double oil which as expected can really foul the plugs.

eggsuckindog · #5 04-05-2010, 10:34 PM

You need to check the connections, sounds like thats what it is, otherwise it would stay on, check the engine plugs too there is a big one near the starter

does your DF have voltage? my lowrance does and that may show it

jwclbi · #6 04-06-2010, 05:26 PM

Well after new plugs and a new fuel/water seperator the beast seems to run fine. Last fall I had it running on the trailer for 5 min. and did the same thing, stumble beep and continue to run. I had it running this afternoon for 10 -15 and no such issue! But I will try again in the water. The plugs didnt have a lot of hours on them but I didnt change them last spring. Battery is strong and all connections are clean, I'm kinda anal about that, I have had problems in that department with an older everscrewed 75 hp I had. Thanks guys I'll let you know what goes on with next run!

Fr. Frank · #7 04-07-2010, 02:59 PM

Oil tank sensor on my 90 Opti failed, and thought the tank was empty. It would beep, one long beep, then cut the rpms back to max of 1500, and running rough. Every 3 or 4 minutes it would beep for about 5 seconds. Dealer replaced the sensor under warranty, and told me that the motor runs extremely rich to provide extra cooling/cylinder lube when it thinks it's not getting enough oil, as well as limiting the rpms to 1500. (Actually s'posed to limit the rpm's to 1200)

My motor has a whole set of beep codes that can give you a clue as to why it's messed up. I have analog gauges, not the Smartcraft, or it would just tell me what's wrong.