1999 Mercury 115 stalls

[walleye0305]

I have a 1999 Mercury 115 2 stroke.

Problem: When I start the motor, after sitting a day or two, it runs perfect. I can rev it up to 3000rpms and sounds great. When I put it on the water, it seems sluggish. When I begin to give it WOT, it goes sluggishly and dies. Dead on the water. I have to choke the snot out of it and keep trying to start it to get it to run again. When it does run, its rough.

What I have done: I have rebuilt the carbs and fuel pump. Installed new fuel filter and primer bulb. Changed spark plugs.

I just bought the boat. Like I said, it ran fine on muffs. There was no lakes near by so we did not take it to the water. Figured hearing it on muffs would be suffice. (Guess not and lesson learned)

I have heard it could be electrical or even as ugly as a smeared piston.

Fyi... had my 10 year old daughter with me when this happened. Now she doesn't want to go in a boat again. She was scared.

PS: If you ever sell anything, be truthful. Don't try to make a buck on a POS. If you know of problems, solve them or let the person know. Karma will come back around to haunt you!!

 

[carholme]

Re: 1999 Mercury 115 stalls

Start with a compression test so you get some baseline of the engine. Do you have a service manual? If not, send me a PM with your engine s/n and an email address and I will send you a copy.

Gerry

 

[walleye0305]

Re: 1999 Mercury 115 stalls

Start with a compression test so you get some baseline of the engine. Do you have a service manual? If not, send me a PM with your engine s/n and an email address and I will send you a copy.

Gerry

We did a compression test... it wasn't the best tester and allowed a little air to blow back but all of them came out basically right at 80. I do not have a repair manual and will try to PM you in just a minute with my email address. Serial Number is OG922809. Thanks Gerry!!

 

[BatDaddy1887]

Re: 1999 Mercury 115 stalls

Dump an entire can of Seafoam in the gas tank, run it on muffs or on the water if you can. Hopefully this will clean out your carbs. Better yet, is get a 6 gallon fuel tank and dump a can in there and fill it with fuel and run that. If after 30 minutes of running and no better, then maybe it's time to actually clean the carbs the old fashioned way.....removing and cleaning. Also, remove the fuel tank hose and inspect the screen for debris, as well as the fuel filter near the engine. 80 psi does not sound all that great for compression. Buy a good tester and do it again, hopefully you'll get readings over 100 on each cylinder. It's OK to be within 15 percent of each cylinder. Future use of Seafoam varies with each user, but what works wonders for me is half-a-can every other fill-up.

 

[carholme]

Re: 1999 Mercury 115 stalls

Your s/n comes up as:

MERCURY - (115 H.P. (1999 ))
Serial No: 0G922809 Model No: 1115412VD

Parts and Service Bulletin list for s/n 0G922809:

Search Results - Crowley Marine

Manual will be on the way shortly.

Gerry

 

[walleye0305]

Re: 1999 Mercury 115 stalls

Dump an entire can of Seafoam in the gas tank, run it on muffs or on the water if you can. Hopefully this will clean out your carbs. Better yet, is get a 6 gallon fuel tank and dump a can in there and fill it with fuel and run that. If after 30 minutes of running and no better, then maybe it's time to actually clean the carbs the old fashioned way.....removing and cleaning. Also, remove the fuel tank hose and inspect the screen for debris, as well as the fuel filter near the engine. 80 psi does not sound all that great for compression. Buy a good tester and do it again, hopefully you'll get readings over 100 on each cylinder. It's OK to be within 15 percent of each cylinder. Future use of Seafoam varies with each user, but what works wonders for me is half-a-can every other fill-up.

BatDaddy, I have done the seafoam prior to working on the other things. Didn't really do anything unfortunately. I have not checked the fuel hose screen... this I will do next! I did clean the carbs and put all new seals in them. Fuel filter was replaced. As I said, I will check the fuel screen next and see if this may be the culprit!!

Thanks!

 

[walleye0305]

Re: 1999 Mercury 115 stalls

Your s/n comes up as:

MERCURY - (115 H.P. (1999 ))
Serial No: 0G922809 Model No: 1115412VD

Parts and Service Bulletin list for s/n 0G922809:

Search Results - Crowley Marine

Manual will be on the way shortly.

Gerry

Thanks Gerry! I will print it out so I have a hard copy as well.

 

[Dave1027]

Re: 1999 Mercury 115 stalls

Sorry to say but I think that motor needs to get into more learned hands.

 

[walleye0305]

Re: 1999 Mercury 115 stalls

So, I pulled the secondary fuel filter last evening and replaced it. (Didn't know there were two). Took it to the lake to see if the motor would run under pressure as opposed to on muffs. This didn't work (of course) and when I was pulling the boat back out of the water, I could smell the strong odor of gas? I took the boat back home and began digging around... pulled the batteries (3) out and began looking at the fuel tank hoses. I found that the vent tube was broken. Its the 5/8" hose that runs from the 2 top side connectors. Could this be the culprit? Im going to get a new hose today for sure but wanted some input. Since this hose has a hole in it, who knows what could have gotten in the fuel tank. (its a very big hole in the line) Would you suggest draining the built in fuel tank? How the heck do you clean them when they get emptied? Sorry for all the questions. You guys are great!

 

[walleye0305]

Re: 1999 Mercury 115 stalls

I replaced the hose the hose that was broken. Took it back down to the water and same thing. Not sure if I mentioned this before... when I rev it up, it blows allot of white smoke out the exhaust as well. Still wondering if draining the fuel tank would be the next step?

 

[carholme]

Re: 1999 Mercury 115 stalls

I think you are just wasting your time and hoping for a magical answer to your problem. In my opinion, if you do not resolve the compression issue you really do not have a starting point to work from.

Gerry

 

[walleye0305]

Re: 1999 Mercury 115 stalls

I found the problem!!!! I believe the previous owner must have really put some water in the boat somehow and it leaked into the gas tank. I went and purchased a 3 gal fuel tank and filled it up with gas, swapped out the ball pump and headed to the lake, AGAIN. Fired it up, it ran rough for a couple minutes, im sure because it needed to get the rest of the fuel from the tank out of the carbs and lines. Took it out for another spin and and took off like a graped ape! Went back and forth about 6 times at full throttle without dying on me. Now, next questions... since there is water in the tank and obviously it was ran thru the motor, what all do you think I should do after draining and cleaning the tank as far as on the motor? Should I clean the carbs again, change spark plugs again or rebuild the fuel pump?

 

[Supervhell]

3&4 cylinders have a check valve that open at about 1800 rpm have theses checked to see if they are hung open.

 

[Faztbullet]

This post is 6yrs old!!!!!!!

 

[racerone]

A " check valve " on 3 and 4 -----That is a new idea.-----This thread will go " boom " soon.

 

[GA_Boater]

:boom: