Change the oil??

[mrallen007]

I have a 50HP oil injected Merc. I can't seem to keep it running. If I give it the ol college try, I can get her to crank, but she won't stay running. The last time I had her on the water, I got her to crank, but as soon as I took her off high idle, she croaked. I fired her off again and left her in high idle. She died while in high idle. At that point we went to IHop.

I've been trying to determine what's going on. A fuel pump or some sort of ethonol problem have been suggested. I wonder this. Do I need to drain the oil in the resevoir and change it? Does it break down and go bad? Any thoughts are welcome.

 

[carholme]

Re: Change the oil??

mrallen;

Have you tried to see if it will continue running while you keep squeezing the bulb?

Do you have a s/n for the engine?

Gerry

 

[Silvertip]

Re: Change the oil??

When was it run last? Are you a regular user of fuel system treatments? If not you should be. How old is the gas. Water in the fuel? When were the plugs checked last (or replaced for that matter). Changing oil on a two stroke is not necessary unless it has been contaminated with water. Besides, that has nothing to do with the fact that the engine won't run. The engine will run without oil (for awhile at least). Details, details, details.

 

[mrallen007]

Re: Change the oil??

Actually, I have not tried that. Serial # is 0D032852.

 

[mrallen007]

Re: Change the oil??

When was it run last? Are you a regular user of fuel system treatments? If not you should be. How old is the gas. Water in the fuel? When were the plugs checked last (or replaced for that matter). Changing oil on a two stroke is not necessary unless it has been contaminated with water. Besides, that has nothing to do with the fact that the engine won't run. The engine will run without oil (for awhile at least). Details, details, details.

It was last run in August of 2010 the day I bought it. I bought it from a friend and it ran just fine. I do not know what sort of fuel or fuel treatment he was running at the time. The next time I ran it, I added fuel and treatment, but not one that was rated for ethonol. I did not learn of the dangers of ethonol until after this. It ran for a little while that day and then stranded me on the lake. The guy that towed me in graduated from MMI and said it sounded like a fuel pump. That is when I started the mission to get it back running. I changed all the plugs in early September. I changed the fuel filter. I added a fuel/water separator.

I changed out all the fuel dumping what was in there into another container for the lawn mower. I added Sta-Bil Marine for ethonol to the fuel at the same time. So the only questionable fuel was the first time I ran it alone with a mixture of somewhat treated gas and mystery gas. Last few times I had her running was on good gas with good treatment, but in an old tank. I've not replaced fuel lines. I added the separator inline with the existing lines.

What else... Carbs have not been worked on. There was some damage in the linkage that opens the carbs. A bushing failed and the metal linkage fell out. I replaced that and have had on and off results since.

I can get her running in the driveway with muffs, I just can't get her to run on the water. Feel free to prod me for any other details I may be leaving out. I just want this thing to work.

 

[carholme]

Re: Change the oil??

mrallen;

Your engine comes up as;

50 D000750 - D081999 1991

From here:

http://www.storesonline.com/site/573683/page/609764

It is a model:

1050412LD MERCURY 1991 50

Parts Listing:

http://www.crowleymarine.com/mercury-outboard/571.cfm

Service Manual:

http://1manual.com/Mercury manuals/Service Manual PDFs/TwoStroke/817643r1/cover.pdf

You can download the various sections of the manual which you will see listed as you scroll down the page.

If you do try the engine in the water have someone at the bulb and keep squeezing it to see if the engine will run once it is started. This is usually a ggod sign that the fuel pump is not delivering fuel once the amount in the carb is used up.

Gerry

 

[cam4888]

Re: Change the oil??

I had the same problem (four stroke though) took the carbs off and the large jets were good but every one of the small ones were clogged solid. if you manually keep it choked and it runs this is might be the problem
this was after leaving it for about five months with gas and sea foam in it.

 

[mrallen007]

Re: Change the oil??

I've not checked for clogged carb jets. For that matter I don't have any idea how long it's been since the carbs were serviced. I may have a go at that before I spend the money to put it in the shop.

I'll also see about manning the bulb while it's running to see if the fuel pump is still suspect. Looks like I know what I'm doing when I leave the office today!

Thanks guys. Any further assistance or ideas are greatly appreciated.

 

[1979checkmate]

Re: Change the oil??

I changed out all the fuel dumping what was in there into another container for the lawn mower. I added Sta-Bil Marine for ethonol to the fuel at the same time.

Don't waste your money on sta-bil "marine," if you really want the "marine" sta-bil then get yourself a bottle of regular sta-bil and put in a few drops of blue food coloring, ta da! IF you REALY want to treat your fuel with a quality treatment, use mercury quicksilver quickstor. This is a quality product. I have used sta-bil in the past, but i am switching to mercury.

 

[j_martin]

Re: Change the oil??

I would guess you may have several problems. Small passages clogged in the carbs might be one. If the fuel had a bit of water in it when you tried it, and some of that water remained in the carbs, it would have formed sludge over the winter.

Also, you say you worked on the linkages. There is a procedure in the maintenance manual called linkage and timing adjustments. (Link n sync) If those adjustments are not made correctly and in the right order, the engine will run like crap if at all.

 

[mrallen007]

Re: Change the oil??

I think you are absolutely right. I know engines pretty well, but I'm quite the newbie when it comes to outboards. I was hoping this would be something I could easily address, but I'm leaning more and more on taking it to a good shop so they can give it a once over and let me know what all really is wrong. With any luck I can get her on the like this summer without having to use the paddles!

 

[mrallen007]

Re: Change the oil??

Don't waste your money on sta-bil "marine," if you really want the "marine" sta-bil then get yourself a bottle of regular sta-bil and put in a few drops of blue food coloring, ta da!

Nicely said!

I'll look into the Quicksilver stuff too. I'm gonna buy a new fuel cell so I know I'm pulling from a clean tank. Starting from scratch. Worth starting from scratch with quality products...

 

[j_martin]

Re: Change the oil??

Actually this engine is less than half as complicated as the typical automobile engine. There's nothing you can't handle under the shade tree until you get into major tear down. Everything to and including the reeds from the front is easy, and everything to the pistons from the back is easy. Ignition looks complicated but it's just 6 copies of a chain saw system.

If you got the manufacturer's manual, and went once through it, compression test, carb kits, fuel pump kits, hose routing and condition inspection, maybe even pull the reed plate and inspect the reeds. (about 14 bolts more once the carbs are off.) Put her back together and do the adjustments by the book, and you'll have a good running motor, and know what's in it.

While yer at it, drop the lower and check out the water pump.

hope it helps
john

 

[mrallen007]

Re: Change the oil??

Thanks for all the help guys!! I think I may be a little closer to figuring this thing out. I posted a new thread. Have a look and let me know if you think I'm on the right track. Thanks again!!

http://forums.iboats.com/showthread.php?t=464954

 

[mrallen007]

Re: Change the oil??

There's nothing you can't handle under the shade tree until you get into major tear down.

Thanks John! I've always been a bit warey about getting into outboards. It's nice to hear from an expert that they're not so bad.

On a tip from a gent at West Marine, I pulled the fuel line from the carb and turned her over. He said if I got no fuel at that point then it's likely the fuel pump just needed a rebuild. That's exactly what happened. I pulled the fuel pump apart and the sucker is filthy. I have a diaphram kit on the way now. Hopefully with a little tlc, this thing will be operational soon.

Thanks my friend!