2005 150 Optimax gas problem?

Rannger361

New member
Ok guys I need your help/advice. I have a 2005 150 Optimax with about 1000 thousand hours. First of all I've recently changed plugs, fuel pump, water pump and lower unit. It want idle longer and a couple minutes but it runs great when you first take off. After that it has a slight miss coming out of the water and mph will drop from 60 to 56 the remainder of the day. When I'm done and drain the water from the prop I have gas coming from the prop area. The compression is even on all cylinders. Any thoughts?
 

churly

New member
The diaphragm on your fuel rail is probably split or has a tear in it. Dealt with it on an '05 175 opti. Back then mercury would only sell the entire fuel rail. $$$$. I found a guy in Texas, His business was called "Pelican services" in exchange for your old diaphragm, he would send out a replacement for like $300. Your stock mercury diaphragm is under the silver cap on the fuel side of the rail, not the air. And it is a green rubber diaphragm with a braded metal button in the middle. Hope this helps
 

silvertalon

Active member
Mercury now sells the diaphram for the pressure regulator but you will need the tool to disassemble it. Its not a cheap diaphram. I think its around $50. Could be the tracker valve too as it balances out pressure differentials on demand. I'd replace both especially if never done before. Of course the 1st thing to do is run a fuel/air pressure test to determine where to start. Also be sure to gap your plugs as precise as you can get them with a wire gauge. PM me about bringing it in, servie etc.
 
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