White Smoke/misfire optimax 250 xs 2003

**Edgewater225** · 05-29-2023, 04:37 PM

Thanks in advance for the help. I’ll start by saying my mechanic retired and everyone had a waiting list so I had to take on a bit more than expected.
Optimax 250 xs 2003.
Last season I changed my spark plugs. I googled the ones needed and made sure to tighten them to the correct lbs. Finally got the boat in the water today but had to pull it out after the first run.
Motor ran fine at under 2k rpm’s. Same as usual so I expected a good day on the water. Unfortunately as soon as I increased the RPMs lots of white smoke and very little power. Ok, I backed off. Figured maybe steam, maybe clearing out some stuff from the winter. Let’s try again.
Pushed down, looking good. 5500 rpm’s clean air. Then misfiring (or looked as if the engine was starving for fuel or bucking). Backed off. Went back to 2k rpm’s..business as usual. Puttered around at 2k rpm’s for a bit. No issues. No smoke.
ok, time to try one more time. Ran it at 4-5k rpms to get back to the mooring, no problem this time. Figured it wasn’t time to press my luck. I thought I was Lucky to get back in and obviously there’s an issue and I’m not looking to make the problem worse.
grabbed my mooring. Decided to push in the throttle only button and see what the motor did at high rpms on the mooring. Well, tons of white smoke again. Shut it down, and 2ked it to the launch. Pulled the boat and it’s in the driveway for repair. I also found a small leak but that will be a different post. Guess I should stick with the pool!
I’m I right to think spark plugs? Or should I just get on the waiting list for the mercury guy?
thx! Boat and motor photo below

**rock** · 05-29-2023, 07:14 PM

check your compression

Rock

**David - WI** · 05-29-2023, 07:19 PM

Isn't there some problem where Opti's get water into the air compressor? I thought I read it here years ago.

(Also, do you really have to trim it up that far?)

**Edgewater225** · 05-29-2023, 07:29 PM

QUOTE=rock;3390172]check your compression

Rock[/QUOTE]

thx just did today

120/115/115/115/110/115
these are the plugs I used. Maybe they are the incorrect ones?

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**David - WI** · 05-29-2023, 09:42 PM

White smoke is usually water, blue smoke is oil, black smoke is fuel.

**XstreamVking** · 05-30-2023, 07:24 AM

2 out of 3 plugs look steam cleaned.

**InjectorService** · 05-30-2023, 11:08 AM

You sure those are the right plugs?

EDIT: I should have specified, the Optimax are picky on plugs. There are "G" plugs and "J" plugs, one is long reach, one is short and they coincide with the color of the air injectors. If I'm correct, that should be a 3.0L motor with the GRAY air injectors, and the IZFR6J plugs.

**Edgewater225** · 05-30-2023, 08:11 PM

Thanks, you might be right. Going to find a website to confirm. I appreciate it

**Edgewater225** · 05-30-2023, 08:12 PM

Agreed on the steam clean. 100%

**Edgewater225** · 05-30-2023, 08:22 PM

Originally Posted by InjectorService

You sure those are the right plugs?

EDIT: I should have specified, the Optimax are picky on plugs. There are "G" plugs and "J" plugs, one is long reach, one is short and they coincide with the color of the air injectors. If I'm correct, that should be a 3.0L motor with the GRAY air injectors, and the IZFR6J plugs.

well looks like you might be right

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**XstreamVking** · 05-31-2023, 07:41 AM

My 250 pro xs opti likes the izfr6j ngk plugs. They need a 042 gap. Think I remember that If you order the izfr6j-11 they are pre gapped at 042. Opti's are picky about plugs, spark gap, and coils.

**Edgewater225** · 06-12-2023, 08:43 AM

Originally Posted by InjectorService

You sure those are the right plugs?

EDIT: I should have specified, the Optimax are picky on plugs. There are "G" plugs and "J" plugs, one is long reach, one is short and they coincide with the color of the air injectors. If I'm correct, that should be a 3.0L motor with the GRAY air injectors, and the IZFR6J plugs.

they were in fact the incorrect plugs.
I swapped them out for the correct size ran it on muffs a bit and then around the harbor for 5 mins yesterday. Still tons of white smoke.
I plugged the plugs to see.
Here’s what they look like.
many thoughts?

**XstreamVking** · 06-12-2023, 09:09 AM

Something is cleaning 3 of them. Sure looks like steam is the culprit. Does it run even close to normal, as in rpm's and power at plane off?

**Edgewater225** · 06-12-2023, 09:13 AM

Originally Posted by XstreamVking

Something is cleaning 3 of them. Sure looks like steam is the culprit. Does it run even close to normal, as in rpm's and power at plane off?

I agree. I’m going to move on to a leak down test I think. Compressions were good 120/115/115/115/115/120 but I also didn’t think they looked right.

I’ve honestly been to nervous to take her out a push the throttle thinking I’d damage even more at this point.

**InjectorService** · 06-12-2023, 09:29 AM

Put the plugs back in, pull the air dump hose out of the adapter and see what comes out while its running. Looks like water to washed to me as well. Its tough to see in the pictures, but do the plugs (particularly the clean ones) have any beading liquid on them? Fuel doesn't bead, water does. If its beading, its definatley water.

If you have water in your ssytem, pull the head off your compressor and inspect the seals. Might as well pull the compressor crankcase off and go through the whole thing too.

EDIT: and a leakdown is never a bad idea, but I don't think that is what you have going on here. Do the above stuff first IMO.