02' Mercury 225 OptiMax problem??

[PCspearo]

I recently bought a boat with a 225 Mercury OptiMax 02? and until the second trip and 20 miles offshore it ran fine. Once out I turned the motor off and after that it did not want to crank back up. I noticed the fuel bulb was empty and pumping it would not make it tight. I finally got it running again, but on the way back it would barely get on plane even at full throttle and I had to remain at full throttle to just barely keep it on plane (it would not run faster than 3500rpm). My initial thought was that I have a leak in the fuel line letting in air. So I checked all the hoses, connections, and such. I narrowed it down to the fuel filter/water separator and after some adjustments I thought I fixed the problem. I test ran the boat again and it ran better, but topped out at 3900 rpm. The bulb would gradually lose pressure so that problem is not completely fixed yet, but I think there might be another problem since the bulb was tight for at least half the run and it still did not have full power. I checked the spark plugs and they all seem fine except for a little carbon build up. Also it initially required no throttle on cold starts to crank, now it takes some throttle until it warms up. After it warms up it idles fine. Any suggestions???

 

[rndn]

Re: 02' Mercury 225 OptiMax problem??

Welcome to the forum. It sounds like it's not getting enough fuel. How's your fuel pump? Clog in your tank? Water in your tank? Kinked fuel hose?

 

[Fenwick2]

Re: 02' Mercury 225 OptiMax problem??

"Also it initially required no throttle on cold starts to crank, now it takes some throttle until it warms up." That is not good with a fuel injected motor. That can cause a code that will limit your rpm's. Someone here smarter then me can comment on fixing that.
Replace the fuel bulb, they go bad. The check valve can break and I think there was a notice back in 2001-2004 about this problem. Good Luck.

 

[hkeiner]

Re: 02' Mercury 225 OptiMax problem??

Mercury has published a service advisory explaining how to troubleshoot fuel starvation. This might be of help to you.



http://www.marinepartsman.com/Mercury-Marine-service-bulletins/Mercury-Mariner/2001/EN_17.PDF

 

[Don S]

Re: 02' Mercury 225 OptiMax problem??

You also have electric fuel pumps, pressure regulators, VST, direct injectors for fuel and air injectors. Any of which could be a problem.
You really need to get an OEM service manual, the proper fuel pressure gauges and start doing some testing. What is your engine serial number. It would sure help in identifying exactly which system you have.

 

[PCspearo]

Re: 02' Mercury 225 OptiMax problem??

The serial number is OT471301. It is a 225XL Optimax Saltwater Series.

Thanks for all the information, I tried the three tests in the Mercury Service Advisory you provided, but it passed all the tests. If I understand it correctly the only suggestion it had for my situation is to replace the primer bulb. I will give that a try, but otherwise I am at a loss.

Any other thoughts??? Thanks in advance.

 

[hkeiner]

Re: 02' Mercury 225 OptiMax problem??

The fuel starvation test was a good start. As Don S pointed out there are many more components on an Optimax that could be the problem. Performing systematic troubleshooting is better than randomly replacing parts on a hunch or educated guess. However, systematic troubleshooting requires the appropriate tools and skills, along with a Mercury shop manual for guidance. It is not too hard to do such troubleshooting on a carbed outboard, like mine, but I understand that the complexity of the Optimax requires troubleshooting at a much more advanced level. Perhaps out of reach for some of us. Take a look at the shop manual and then decide if this is something you want to handle yourself or not. If your motor is running lean, you definately want to fix this ASAP before it causes engine damage.

 

[Don S]

Re: 02' Mercury 225 OptiMax problem??

90-859769R03 is the Mercury part number for the OEM service manual for your engine. They run about $70, but that is a lot cheaper than many of the parts that could cause your problem.

 

[PCspearo]

Re: 02' Mercury 225 OptiMax problem??

Thanks guys, I really appreciate the help.

 

[Bob Gilvary]

Re: 02' Mercury 225 OptiMax problem??

Anti-siphon valve at the fuel tank pick up???

 

[j_martin]

Re: 02' Mercury 225 OptiMax problem??

I hope you haven't done it yet, but you need to know that if you keep driving a fuel starved 2 cycle, there is a good chance you could do serious internal mechanical damage. It's a function of overheat from a lean mixture, probably the main killer of pistons on these engines.

hope it helps
John

 

[wscaman]

Re: 02' Mercury 225 OptiMax problem??

MY 02 was an early manufactured on.

Turned out it was #4 & #6 injectors that were bad . thy were 3 original and 3 blue dot. On solid blue so I was upset that a 3rd generation was already out.
But not on my engine.

My #6 cylinder was bad.


I have a new 2005 power head and upgraded 2005 ecu, have to warm up on cold days few quite a few minutes.