Optimax cutting out, water in gas?

[staylor]

..sort of like the ones on my 2002 Opti 150, but with the large number of trolling hours I's change them anyway- making sure you get the right P/N- should be NGK IZFR5G. Torque to 20 ft-lbs- leaving lots of time to change the lowest plug on the port bank. After the plugs are in, wipe a very thin film of Merc 24c lube on the insulator so the boot doesn't weld itself in place over time. Make sure each plug wire is firmly on the plug- the 2 lower plugs on the port bank are known to be tough ones to get the wires seated. A plug wire that is not fully seated on the plug will cause just the miss that you have...and don't ask me how I know this!

While you're doing this, look at each coil terminal to make sure that no carbon "wires" or "hairs" have formed that can short the terminal. I had a Merc 2 years back with an intermittant miss that ended up due to a half inch long carbon hair that had built up over 8 years on one of the low voltage connections to the point that it was arcing out when I hit a wave.

I second ohiojmj's post about emptying out the water separator filter and re-installing it. If the plug change and draining the filter and checking the lines and primer plug doesn't fix it, then a trip to the dealer is needed to look for a bad coil or ECU- and hopefully it's not the ECU.
Doug

[JohnG]

Originally Posted by staylor

I second ohiojmj's post about emptying out the water separator filter and re-installing it. If the plug change and draining the filter and checking the lines and primer plug doesn't fix it, then a trip to the dealer is needed to look for a bad coil or ECU- and hopefully it's not the ECU.
Doug

Can you tell me how to check out the water separator? I'm not afraid to give it a shot, but I wouldn't know where to start.

[Hot Runr Guy]

Originally Posted by JohnG

Can you tell me how to check out the water separator? I'm not afraid to give it a shot, but I wouldn't know where to start.

Here is the water filter info from your owners manual.
HRG

[REW]

John,
Take the water separator filter off of the boat, tip it upside down and drain everything that is in the filter.
Then reinstall it.

This, of course, if you have a separator on your boat.

REW

[JohnG]

Originally Posted by Hot Runr Guy

Here is the water filter info from your owners manual.
HRG

Wow, thank you.

Do I need to disconnect the gas line from the motor before removing this filter? Do I need to worry about fuel being pressurized from the ball at all when removing the filter?

[staylor]

..no need to bleed off pressure since there is no accumulator in the lines- as you would find on auto fuel filters nowadays. Just have a few rags handy since you'll probably spill some gas while working the filter out. If you have the spin on type filter- like I have on my 2002 Opti 150- then it would be good to have a new filter handy- since sometimes you mess them up getting them off.
Doug

[JohnG]

Originally Posted by staylor

..no need to bleed off pressure since there is no accumulator in the lines- as you would find on auto fuel filters nowadays. Just have a few rags handy since you'll probably spill some gas while working the filter out. If you have the spin on type filter- like I have on my 2002 Opti 150- then it would be good to have a new filter handy- since sometimes you mess them up getting them off.
Doug

Thank You Doug,

I thought I'd update this thread, it suddenly hit me when I was removing my lower cowling to prepare for my plug replacement (who the *&^! decided it was a good idea to put the bolts on the inside of the cowling instead of the outside!) when I realized that when we ran the boat at the dealership before I bought it, we had it hooked up to an external gas tank as the boats onboard gas tank was dry. After running the motor the tech reconnected the gas line to the on board tank, which I then forgot about as I parked it in my shed for the next 3 months. I then realized that I filled the tank when I took the boat out for the first time, and that I may not have primed the bulb enough since it was a completely dry tank and lines, so I checked the bulb as I was standing there thinking about all of this. It turns out that the bulb wasn't completely hard, and it probably took 10 pumps to get solid and stay solid, so I'm guessing I may have just not primed the system enough the first time.

I'm going to replace the plugs anyway since the motor has 120 hours on it and 100 of them are at or near idle, and I would guess they're original anyway. I'll take it out this weekend with new plugs and see if the new plugs/proper bulb priming fixes the WOT cutting out issue.

[115 optimax]

Originally Posted by JohnG

Can you tell me how to check out the water separator? I'm not afraid to give it a shot, but I wouldn't know where to start.

You can watch a video on you tube on how to clean the water separator.

[staylor]

Oddly enough, I had the bulb go bad in my 2002 Opti 150 after only 5 years- the internal check valve reacted badly with the added 10% alky forced upon us by the Fed. The bulb would not stay firm and the motor ran a bit ratty. I went to buy a new bulb, but my dealer had them on backorder since evidently I was not the only Merc owner with a bad bulb. I went to the Yamaha dealer and picked up one of their bulbs which had the latest alky resistant rubber and it's still on the motor today. After you swap the bulb, check the lines from tank to motor to make sure they aren't soft or swelled or cracked from alky. If all looks good, check all the clamps from tank to motor to make sure they are all tight. I double clamp all my fuel line connections using the easy to use OMC/Bombardier nylon clamps that come in several sizes, require no special tools, and grip the line for a full 360 degrees. I even used these on the Holley 4bbl dual feed lines on my old '71 Cuda- and they were the only clamps I found that did not leak over time.
Doug