150 mercury question

Just got back from canada walleye fishing and had boat trouble and was looking for some ideas. Have a 150 mercury verado 4 stroke engine and the crank case filled what I thought was fuel. Brought it to mechanic and he said it was normal for a 4 stroke to as he called it make oil if idleing alot. So Knowing that we idled enough to fill the crank case.This is a first for me to hear of this. Any thoughts or ideas. Now as for the fishing 10 of us when and stayed on a house boat and tocaught aproximently 700 walleye a day never seen it that good been for 20 years.

Yes the rings stick from ( carbon build up) continued slow running and idleing a lot.....Thats why you should add one ounce of Ring Free for every 10 gallons of gas you put in. This is what I do and I also try to run the snot out of it when I get though fishing before I put it on the trailer. Since I have been doing this I have had no problem and no more gas in the crank case.

Like G said its normal for oil to build up and when you get done just run the $%$%%% out of it to clear the oil. Be thankful it does that, the option isn't so good.

Thanks for the insight. Did add ethonal treatment but no ring free. Does marine stable due the same thing?

It will help, but if your doing alot of low speed idling with the big motor than ring free will be a plus for you. It will reduce the build up on the pistons and other parts of the motor. I'am no mechanic but this has worked for me in the past.

No.....You need to use Ring Free....it removes and prevents carbon build up. Slow running, long idleing , trolling a lot etc. causes carbon to build up and that makes the rings stick......this causes gas to get into the crank case. Yamaha makes Ring Free and recommends its use in four strokes. Yamaha builds the four stroke power heads for Mecury on the larger motors now. But no matter the brand.....Ring Free should be used to prevent this. Mix it carefully .....you do not want to get too much in the gas....just one ounce for every 10 gal of gas. You still need to use your Marine Stabil as well.

I will also add use Sea Foam in it with every tank of gas. My cocktail consists of Mercury quickleen, Marine Stabil, and Sea Foam. I mix 1 once of each per 6 gallons of fuel. Works great for me and no engine problems thus far. I would guess you should probably use a shock dose of Sea Foam to help clean your motor out. I would add 4 onces per 5 gallons and run the piss out of it to clean it. A long WOT run should help it a great deal.

I don't have a four stroke engine, but seem to remember reading an article about someone who was pulling their boat behind a house boat and they had some issues. I can't remember the details, but if you were "trailering" your boat in the water behind the house boat, that may have something to do with your problems, but then on the other hand, I may be full of hooey!

I have only heard of those kinds of walleye days in Canada. It sounds awesome!!!!