Oilly sludge seeping from exhaust

[ThanksandGigem]

A month or so ago I rebuilt my carbs ran out and tested the outboard and everything ran great. I have been recently doing some cosmetic work on my boat and it's been sitting in the driveway I started to outboard a couple time on the hose and what I noticed recently is that there was some oily sludge seeping from the lower exhaust at the prop. Initially I thought It was possibly LU Oil so I drained a bit out and no signs of waterso I pulled the LU checked and no signs of leaking oil in or around the water pump or shifter shaft seal. However, there was residue similar to the crud that was draining out in the exhaust above the LU. I assume this is residual carbon and unburnt two stroke oil.

I checked the spark plugs with an ohm meter and 0 to 0.002 resistance on all I then moved the plugs around to different cylinders and restarted the motor. It started and sludge kept seeping out. Also sounded the same. I tried pulling the wires and what I found was that the rpm and sound didn't change very much when pulling off the lower or middle two plugs but the motor dies if I pull off either of the upper two plugs.

The gas was quite old and the tank was almost empty so I put new 93 in the tank today and ran the outboard only difference was the color of sludge this time it was much lighter before it was between black and tan

Any Ideas?

The outboard is a 1999 C150 TXRX

[ThanksandGigem]

I found the issue. I tested the spark on all the coils and they are firing. Ended up taking the breather off and found the center carb flooding. Seems the needle valve wasn't sealing all the way so I removed it and adjusted the floats a bit they were a tad under 16mm. Also reset all the idle screws to 1and 1/4 turns. Now it sounds much better and idles is better too. Only thing I noticed is idle is around 900 now and if I pull the spark boots off I can hear a difference in idle with pulling the upper 2 and middle 2 but not the bottom. I know the idle speed is a bit fast I'll try and do a link and sync tomorrow

[ThanksandGigem]

I synced all the carbs per the maintenance manual and the idle jets are all set between 1 and 1.25 turns the idle sounds good and is around 700 rpm however there is still no slow down if I pull the plugs on either of the lower two cylinders I don't hear a slow down and the RPM doesn't change. However with the upper four as stated before I do notice a difference in the sound of the idle and the rpm slows slightly.

Shouldn't I expect it to slow just the same with the lower two? I have pulled the spark plugs from all cylinders and they are just lightly wet with fuel

[TownsendsFJR1300]

Did you do a compression test on all the cylinders? If so, are they all within 10% of each other?

You may also have a fuel pump diaphragm leaking into the block causing the cylinders to foul with extra fuel, not fire ( and no change when pulling the plugs)

[ThanksandGigem]

Did you do a compression test on all the cylinders? If so, are they all within 10% of each other?

You may also have a fuel pump diaphragm leaking into the block causing the cylinders to foul with extra fuel, not fire ( and no change when pulling the plugs)

Brand new fuel pumps and compression test back with all cylinders @ 85-87psi. When pulling the plugs they aren't overly wet. The same as the other 4 at least