I have a 2004 115 Optimax serial# OT921044 with about 170 hours on it. For a few years now (or maybe longer), it's seems to run a bit rough at forward and reverse idle, when the throttle has just engaged forward or reverse. Not all the time - seems first trip out on the lake it runs smooth, but later, maybe after having warmed up, it gets rougher. Never dies, and the RPMs seem to be about 700 or so (no smartcraft gauges). Pushing it forward just a bit always smooths it out, and no problems anywhere else in the throttle. It has no problem getting to ~5,600 RPM and running there. No misses to speak of.
I had it to the dealer a month ago to put in a new water pump. I explained the symptoms and my concern to him then, and he didn't notice anything of concern when he fired it up. He didn't pick up any codes that concerned him. Plugs look good, about 10 hours on them and they are dark but no buildup and not oily. Just checked compression and it is about 112 PSI on all three cylinders. I use Opti oil and run a can of seafoam through with each fill-up since it's readily available.
Yesterday when I had it out, I also believe I noticed a couple random, single beeps when pulling a tube behind the boat over a three hour period. I was in the front of the boat at the time and someone else was driving at about 4000 rpm. Can't swear they were from the alarm, but I mention that in the off chance it could mean something.
All of the coils were changed about 6 years ago under a recall or warranty by the dealer.
Thanks for any help you can provide.
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