[happymotor1]

Help,My Optimax 225h(2004) is having problems which no one seems to be able to fix.
My engine runs fine at anything over 1000 rpms. When at idle tied to the dock the engine stutters and eventually stalls.
The last repair person had me change to the Hgiher grade Mercury Oil and use a better grade of gas thinking that the exhast system was clogged with sludge and that this change would clear up the problem. I started this last November. I did this for a couple months and there was no change.
Last month he said and showed me that when the engine is tilted up a little,
the stuttering stops and the engine appears to run fine. When the engine is trimmed down that exhast would would eventually come out of the prop hub and it was at this point that the engine would start running poorly and eventualy stall.
This has been going on a long time. Over 12 months. Plugs changed twice. No effect. Compression tested OK. 580 hours on engine.
I am a 2 time Mercury owner and I am becoming very unhappy.
Any idea's?

[Langpie]

I am having pretty much the same problem on my 2004 Mercury Saltwater series. It will stall at idle or just in gear but underway she runs like a champ. I noticed while on the trailer at home flushing the engine it will run fine at idle and never stalls. So if someone replies to my thread about my problem ill post it on urs. Good Luck

[happymotor1]

Langpie, I spoke with Mercury. They told me to use a triple gas treatment of Quick Cleen. I am still in the process of running over 100 gallons. Will keep you posted. I am now noticing a surging power at idle.

[happymotor1]

Langpie,
I believe my engine is fixed. I willl test this weekend. I had a Mercury service company look at it. He said there was a hole in the diaphram between the fuel and air pressure.
I have listed a response below that I got from an earlier thread. The problem was that I didn't know what "woody66912" was talking about. I should have gave his reponse to the last guy servicing the motor.

woody66912
Petty Officer 2nd Class
Join Date: Jul 2008
Location: northwestern wi
Posts: 152

Re: 2004 225 Optimax Problems

--------------------------------------------------------------------------------

I'm not sure what was all looked at already.but when optis have idle problems i always check the flowing /fuel lift pump diaphragm / witch would let raw fuel into the engine block. [air] side of fuel rails for excessive fuel in the air side.witch would indicate a failed tracker valve or fuel pressure regulator diaphragm.also the air handler on the front of the engine can be removed to check the reed valves for cracks or chips.not sure if any of this helps.
__________________
don't claim to know it all just hear to help.