I am the original owner of a 1997 Mercury 150 EFI, serial number 0G478627. Amazingly, after 23 years of club tournament fishing, this engine still runs and performs great. However, over the last couple of years, it is getting to where it can be more difficult, at times, to start than others. Sometimes it fires right up on the first try, other times and worst case scenario, it takes 3 tries, none of which requires lengthy cranking.
The only thing outside of routine maintenance, i.e. replacing water pump impellers, lower unit gear oil, spark plugs, fuel filters, and greasing the pivot points, that I have done to this engine is rebuild the pulse pump in the fuel system in 2007. Knock on wood, I have not had to make any repairs to it. It is also worth stating that I am very content with this engine and the boat that it powers, so I have every intention of keeping this engine, and boat, for many more years. Also, I am mechanically inclined and feel very comfortable around my engine. I do have a Mercury service manual for this engine to help me along.
I have three questions:
- Considering the age of this engine, what would you recommend doing to it to fine tune it to be the best it can be and to prolong it's longevity? To be clear, I'm not looking for higher performance upgrades here, just keeping it stock. I want to consider anything and everything.
- What could be the possible causes of the sometimes difficult starting that I described above?
- I would like for someone to confirm for me that I have the correct service manual. The part number of the manual that I have is 90-824052R3. The only reason I ask this question is, for example, in the section titled "Timing, Synchronization, & Adjusting", the only EFI models that it references are the 150, 175, & 200 XRI's and the 150 and 200/225 Pro Max/Super Magnum. I am a little confused as to why I don't see 150 EFI listed.
Thanks in advance and I look forward to hearing the responses.