I have about 600 hours on my Merc 50 2-stroke.
Always been a great engine and never any problems until about the first week in October.
The Voltage regulator went bad on it at that time and after taking a look at the whole situation have concluded that was due to water in the cowling not draining out efficiently due to a clogged drain. Once in a while I find a "skinny spot" in the Columbia River and suck up some sand, which plugs up the spitter. When I remove the hose under the cowling to clear the spitter, a portion of the sand in the hose ended up down into the cowling and found it's way to the drain. The drain has a check valve in it (well, I know that now after ruining the first one trying to pass a wire through it to "clean" it!!) and the sand won't pass through that so it quit draining. Anyway, the result was a slow draining cowling with higher than normal residual H2O under the hood. The regulator sits at the bottom of the "black box" and, even though it is potted, I believe moisture got in there and shorted it out. No big problem. A trip the trusty Mercury dealer (I know ....I could have gotten a cheap after market unit on the web...but I like OEM parts) and $197 later I was back in business.
However, during the first few weekends in November (I had the boat out fishing salmon 2-3 days every week from August through November) the engine started smoking more that usual and not running as smoothly at low rpm as it has always in the past.
I dismissed it as "we'll, it is getting colder and maybe it is just extra steam".
I am colorblind so I was trying to convince myself the "cloud" wasn't as blue as my buddies were telling me it was.
I decided to try decarbing with Seafoam but still had lots of blue smoke on the next few outings.
Then, on the last trip out (good timing eh?) the engine started running very roughly and started "stuttering" at higher rpm.... something I have never experienced with this engine in the past.
Salmon season was done anyway so I took the boat to the mercury dealer and they looked the engine over and are saying they believe the oil injection pump is the culprit. They claim it is sending too much oil to the cylinders and in turn fouling the plugs causing the high amount of smoke and poor engine performance.
I reluctantly told them to go ahead with the work and am waiting for them to let me know it is done.
Question: How does a worn out pump start pumping too much oil? Seems odd to me.
Anyone out there have history regarding trouble with oil injection system on Mercury 2 strokes?
Don B
Always been a great engine and never any problems until about the first week in October.
The Voltage regulator went bad on it at that time and after taking a look at the whole situation have concluded that was due to water in the cowling not draining out efficiently due to a clogged drain. Once in a while I find a "skinny spot" in the Columbia River and suck up some sand, which plugs up the spitter. When I remove the hose under the cowling to clear the spitter, a portion of the sand in the hose ended up down into the cowling and found it's way to the drain. The drain has a check valve in it (well, I know that now after ruining the first one trying to pass a wire through it to "clean" it!!) and the sand won't pass through that so it quit draining. Anyway, the result was a slow draining cowling with higher than normal residual H2O under the hood. The regulator sits at the bottom of the "black box" and, even though it is potted, I believe moisture got in there and shorted it out. No big problem. A trip the trusty Mercury dealer (I know ....I could have gotten a cheap after market unit on the web...but I like OEM parts) and $197 later I was back in business.
However, during the first few weekends in November (I had the boat out fishing salmon 2-3 days every week from August through November) the engine started smoking more that usual and not running as smoothly at low rpm as it has always in the past.
I dismissed it as "we'll, it is getting colder and maybe it is just extra steam".
I am colorblind so I was trying to convince myself the "cloud" wasn't as blue as my buddies were telling me it was.
I decided to try decarbing with Seafoam but still had lots of blue smoke on the next few outings.
Then, on the last trip out (good timing eh?) the engine started running very roughly and started "stuttering" at higher rpm.... something I have never experienced with this engine in the past.
Salmon season was done anyway so I took the boat to the mercury dealer and they looked the engine over and are saying they believe the oil injection pump is the culprit. They claim it is sending too much oil to the cylinders and in turn fouling the plugs causing the high amount of smoke and poor engine performance.
I reluctantly told them to go ahead with the work and am waiting for them to let me know it is done.
Question: How does a worn out pump start pumping too much oil? Seems odd to me.
Anyone out there have history regarding trouble with oil injection system on Mercury 2 strokes?
Don B
