Alarm 2005 115 hp opti

I am stuck! I have twin 2005 115 optimax DFI. I can start out and run for hours at 4to5000 RPMs for hours NO problem. Go down to trolling speed around 2500 and the continous alarm goes off and it goes into safe mode.Drop down to 10 or1500 and it is find again.Try to get back up to 4or5000 it and it goes back to safe mode. I have replace all the pressure seals and the oil filter in the oil system.Replaced the seaweed guard and flushed out with saltaway in the water system. It seems to be peeing well. Any Ideals
Thanks

Re: Alarm 115 opti

could be temp sensor gone bad, or could be blocked passages for water, or could be pumping water but not enough. when was the water pump impellar replaced last.

Re: Alarm 115 opti

Do you have the smartcraft gauges with the (idiot) lights?

Are you getting a check engine, overheat or oil light to accompany the alarm and safe mode speed reduction?

The three conditions which could account for your symptoms are -

1) NO oil flow - with check engine and oil light (if equipped)

2) an electrical failure at the oil pump - with check engine and oil light

3) overheat - with the overheat light

The strong flow at the tell-tale (pee) only means that the waterpump is working and that cooling water is getting to compressor.

The cooling system has three different (branches) - the cylinders, the compressor and the fuel cooler. As noted, you could have a blockage causing an overheat at the heads but still have an excellent tell tale stream.

But also as noted, more often the offender would be one of the temp sensors (one in each head and one at the compressor) which would give you a false overheat condition.

A dealer can "plug in" your motor to a DDT which will quickly spit out the offender - letting you know whether the ECM (thought) the motor overheated, if there was an electrical fault to the oil pump or if the motion sensor at the oil pump detected a (no oil flow) condition....

Re: Alarm 115 opti

Thanks Guys. I am going to replace the water pumps.(impellers) Than go to the cyclinder sensors. The only way I can get it to a dealer is to pull it, and ship it out. Also going to look into getting smart gauges. You suggest any certain ones?

Re: Alarm 115 opti

If possible use regular gauges with numbers instead of lights. They are available through this sight.

Re: Alarm 115 opti

The smartcraft gauges give you the advantage of the check engine, oil and overheat lights which you obviously don't get with analog gauges.

In fact, you must add a module to allow most newer models so they can feed an analog gauge.

Since it is getting considerably more difficult to troubleshoot modern outboards without a diagnostic terminal, the SmartCraft gauges are definately worth their cost especially if you are remote to a dealer and have to do some preliminary troubleshooting on your own.

Merc's "SC1000" Tachometer will also display just about everything you could ever need on a smartcraft equipped outboard.

Re: Alarm 115 opti

Graham, you are correct. I forgot about it being a 2005 when I reccomended analog gauges. sorry