4 Stroke 'making oil'

[Spector]

So I purchased a MacX in the late spring and did a shake down cruise etc and all went well. We went on vacation and the problems started with the engine. (Yamaha 2002 4 stroke F60TLRA) To make a long story short, it was loading up the cylinders, leaking fuel, running like crap. We had a guy look at it and he cleaned the carbs. When he drained the oil, he got an extra litre of fluid. Still ran rough and seemed to be trying to load up the cylinders or run 'fat'. Compression was tested my mechanic at 80 psi across all cylinders.This guy was at a loss. We decided given the time left of our vacation to just leave it on the trailer and deal with it at home.

So I'm home and starting to think about what to do and looking at a possible rebuild. I called a respected mechanic in town and explained the story to him. First thing he says is 'you need to run the sh*t out of it'.

He explained that its common ( especially Yammy) on sailboats and fishing trolling motors for 4 strokes to glaze up and start ‘making oil’ due to the extended low speed operation. They need to be run hard once in a while he explained

So yesterday we took the boat out on Ghost Lake. A few sputters and a stall initially but it seemed to clear up and we ran it up and down the lake for a few hours at WOT. Shut it down for a bit, restarted without any need for throttle. After we got home I checked the compression and it has 150 psi across all cylinders. Oil looks good, no change in level, no fuel leaks etc

So it appears to have worked. Anybody else with a similar story or insight?

[dive4it]

Good to know, My Evinrude (Suzuki) 4 stroke is going to get a little sh!+ run out of it next time out due to your experience. Thanks for sharing.

JT

[DaveB]

Extra Litre of oil will probably foul spark plugs and causing gas fuel line over flow and other problems.
Never over fill oil.
You could have saved time by cking your oil dip and drained excess oil out.
Dave

So I purchased a MacX in the late spring and did a shake down cruise etc and all went well. We went on vacation and the problems started with the engine. (Yamaha 2002 4 stroke F60TLRA) To make a long story short, it was loading up the cylinders, leaking fuel, running like crap. We had a guy look at it and he cleaned the carbs. When he drained the oil, he got an extra litre of fluid. Still ran rough and seemed to be trying to load up the cylinders or run 'fat'. Compression was tested my mechanic at 80 psi across all cylinders.This guy was at a loss. We decided given the time left of our vacation to just leave it on the trailer and deal with it at home.

So I'm home and starting to think about what to do and looking at a possible rebuild. I called a respected mechanic in town and explained the story to him. First thing he says is 'you need to run the sh*t out of it'.

He explained that its common ( especially Yammy) on sailboats and fishing trolling motors for 4 strokes to glaze up and start ‘making oil’ due to the extended low speed operation. They need to be run hard once in a while he explained

So yesterday we took the boat out on Ghost Lake. A few sputters and a stall initially but it seemed to clear up and we ran it up and down the lake for a few hours at WOT. Shut it down for a bit, restarted without any need for throttle. After we got home I checked the compression and it has 150 psi across all cylinders. Oil looks good, no change in level, no fuel leaks etc

So it appears to have worked. Anybody else with a similar story or insight?

[Spector]

Ahh but you missed my point. It was fuel in the oil due to glazing of the cylinders and fuel blowing past rings. I did some google searching and it appears to be a common thing

[DaveB]

Must have missed it as I didn't see anything mentioned (Fuel in Oil) .
Dave

Ahh but you missed my point. It was fuel in the oil due to glazing of the cylinders and fuel blowing past rings. I did some google searching and it appears to be a common thing

[Ixneigh]

That's good to know. My Honda five on the 22.2 seemed to be doing the same thing. Had me puzzled since it gets little actual use and shouldn't need new rings yet. I do run it wide open once in a while but sounds like maybe not enough.

Ixneigh

[bscott]

All 4 strokes need to be wrong out--at least that's what I tell myself everytime I hit an interstate on ramp with my Hemi Jeep Commander, 500 rpm to 5,000 in 3 seconds

My E-tec dealer also recommends WFO once a day--happy to oblige

Bob

[Boblee]

Pretty common wth most motors but am told the new generations like etec can handle it, always used to get wierd looks when telling fellow campers to run their generators a bit harder by loading them up even if the couldn't use eg a 150w light but certainly makes a huge difference to how the motor runs and more importantly how long it lasts.

[Bra dor]

My 1999 honda 50 was making oil due to the thermostat being stuck open. Changed the thermostat and changed the oil.With the stuck thermostat the engine was running cold and didn't come up to operating temperature so the moisture was building up and giving a high oil level. I also run my engine at wot now and again problem solved.

[Catigale]

My Nissan kicker made oil every time I submerged it. I'm going to sell all the extra oil when it reaches 150 per barrel.

[Highlander]

Well I guess Beene & I wil never have that problem !!

J

[cptron]

I wish mine would make that much oil, then I could retire and be out sailing even more.

[MacTommy]

Glazed piston rings and cylinder linings also happen on two-strokes, if they don't receive some punishment from time to time. Obviously, they don't start to produce oil, though.

[Ixneigh]

Concur with running the crp out of them every few times out. My Honda five on the little boat was doing the making oil thing but I knew the issue. They need to get good and hot. Motoring out the channel at idle isn't going to do it.