Running Oil Rich?

[joeim8]

Hello,

I have a 2002 Merc EFI 200HP 2.5L (SN#0T443994).

I think the motor is running rich on oil, as I seem to be fouling plugs quite often and when I inspect the plugs they all seem to be fairly equal but have some noticeable oil present.

I was having this problem prior to dropping a new powerhead in, and seem to be still having it even with a brand new powerhead. I changed the plugs once during the break in period and wrote it up to the double oil in the first few hours however I completed 10 hours and have an additional 5 on it so about 15 total and already had to swap them out again.

The symptoms I get when on the water are just loss of power especially when getting up on pad, but as soon as I change the plugs full power is restored.

Any thoughts on what to replace or inspect are appreciated guys.

Thanks

[EuropeanAM]

Checked fuel pressure throughout the RPM range to make sure it's not climbing/high due to a restricted regulator screen?

[joeim8]

Ok Don so I finally got around to pulling off the regulator I will post some pics. Does the screen come out or how should I go about cleaning it up? I cleaned out the recessed part which did have some small black particles but I didn't want to start prying on the screen as I'm not sure. A buddy is coming over this weekend with a gauge and we will check the pressure but I figured I might as well check what I can now.

ThanksIMG_1779.jpg

IMG_1778.jpg

[EuropeanAM]

Just rinse off the screen with an aerosol carb-cleaner, then blow off carefully with compressed air. Don't attempt to "disassemble" it.

[joeim8]

Ok thanks Don.

[joeim8]

Hi Don and all,

SO since I have performed the above task along with changing out the fuel filter I haven't fouled a set of plugs but I have limited trip since then I suppose. So today I decided to just pull the plugs as I was working on replacing WP anyway, and they still seem to be a little "oily & dark" no carbon build up really just a little dark and oily I would say.

So you mentioned checking the fuel pressure, I just ordered a pressure gauge as my buddies didn't have the proper fitting so I want to give it a try.

My question is what or where can I find the proper fuel pressure levels for various RPM's or is there a certain RPM I should note?

Also just a side question, but since replacing the powerhead and manually setting the break in per the manual, there's no way it would still be in the break-in mode right like adding double oil. It was many hours at least 30 ago that I manually initiated the break in, but I'm not sure there is away I can make sure it exited that mode, unlikely but just a thought.

Thanks

[EuropeanAM]

The break-in clock ONLY counts down when the engine is tucked in trim, heavily loaded, and RPM's above 3500 RPM's. So yes, it absolutely is possible for it to still be in break-in mode if not run PROPERLY during break-in.

An example of this is that we often see Pontoon boats with nearly 100 hours that are STILL in break-in.

Have a picture of the plugs?

How much had the engine idled prior to you pulling them?

[joeim8]

Oh wow ok thank you Don.

Yeah I definitely followed the break-in procedure, trimmed down under load and proper time for each RPM, but I wonder if that's why I fouled a few sets of plugs during and what I thought was after the break in period. As I mentioned I've been running this set for a bit now maybe 5 eight hour days with quite a bit of idling during scouting and they haven't fouled yet but I just pulled them to see if the cleaning of the regulator screen and fuel filter change solved the issue. Good news is they were all the same but like I said oily and darker than I would like to see.

I didn't grab any pics, I will pull them again after the pressure gauge arrives and I can get on the water to get some readings.

I know you mentioned a while back to test fuel pressure at idle, at acceleration, while running after a 5 min run and 15/30/60 seconds after shutting down engine. Is there a pressure range that I should be within during each of these?

Thank you for the reply, really appreciated I will try to post some pics soon.

[EuropeanAM]

Essentially you should have manual-specified fuel pressure at all conditions- with no (or very little) pressure loss after engine shutdown for the periods recommended.