9.9 merc issues

[andrew1234]

Hi, I just bought a 1985 mercy. The guy I bought it off said that it was sitting for a few years but it looked clean and appeared to be in good working order and the compression test was good too. It also fired up with the first pull.

Here's where the problem starts. I used it for one whole weekend with no issues getting it to start except for the last day. Different variations of choke and idle sppeds eventually got it going and it was fine. No problem.

I took it out the other day and it started fine with no issues. On the way back from fishing however the power was slowly dying. And eventually the motor stopped. I'd get it started again and it would run for a few minutes then die. Started it again, same thing until the third time where it just wouldn't start at all.


I changed the gear oil, and spark plug before all this so I'm not sure if its that. However when I drained the gear oil I noticed that it only took a few minutes to drain. Should it not take longer to drain?

Any input would be wonderful.

Regards,

Andrew

[Bass assassin]

Shouldn't take too long to drain the oil. Is the plug fouled?
Carburetor rebuilt?

You could try running seafoam thru the gas and see if it frees up the carb otherwise I'd start there.
BA

[Yakster]

Clogged jets in the carb.
Call Dave at Aim Marine.....just got mine back and it's like I have a new motor.

[toobinator]

Did you open the vent on the gas can? When I was a kid (1000 years ago) we got soaked in the rain because the new to us outboard wouldn't run and we had to row in. Turned out this was the problem.

Ed

[andrew1234]

Ed, ha ha! Yes gas tank was vented

[andrew1234]

Clogged jets in the carb.
Call Dave at Aim Marine.....just got mine back and it's like I have a new motor.

Yakster, would a simple carb clean fix this? That I can do myself. Just out of curiosity, how much did it cost you at the marine?

[Yakster]

It's not rocket science but the way I saw it was if I biff the repair then I could be out more than just a carb....
I had a few other things done so what I paid would not be reflective. Dave's a no BS kind of guy and knows his trade.

[andrew1234]

OK thanks yakster. I'll take your advice!

[smitty55]

I totally agree with the Seafoam suggestion. It's a real cheap tune-up. I'd start with spraying it directly into the carb until it about stalls and then let it sit for a few minutes. Start 'er up and let it smoke. Do this several times. Then run a high ratio fuel mix (some shops run a 50/50 ratio) for a while to clean the entire fuel system. I also always use it in all my small engines, two or four stroke. A light mixture for maintenance and a stronger mix the odd time for cleaning.

There's certainly nothing wrong with taking it into a shop, but if you can fix it yourself for cheap, why not try.
You may also want to check your fuel tank for contaminants.

Good luck with it. Cheers

[Kerrazy]

I second SeaFoam,
If your not too mechanically inclined around small engines it can be a problem doing a full carb cleaning. Settings can be a bugger to tune in if you not comfy with it.

But, it sure seems like shellac from the old fuel has come lose and is clogging the jets.

[Roblin]

Sounds like you have a bit of water in your tank. Depending on the angle of your tank a bit of water is being sucked up. I had a Mariner that did the same thing. I put fresh gas in what I thought was an empty tank. Turned out condensation had cause a little water to pool in the tank. The water would be picked up occasionally depending on the angle of the tank. The motor would bog down. Played with the choke and throttle and it cleared and ran fine. Turned out it had simply used up the fuel with water and ran good on clean gas. It did this off and on for a week. Finally realized that the problem was so inconsistent that it had to be water. Took a close look at the tank and found a little glob of water rolling around on the bottom of the tank. I saved the good gas, poured out the bit with water and no more problems. Motor ran like a champ.

[Georges]

Is it pee pee water sounds like overheating check impeler

[cgates]

Is it sucking air from the line

[PunchRig]

Just take it to Dave @ AIM,, it's an '85 sitting up a long time,get the carb kitted, it may even be a cracked coil, they were famous for those, when it comes out of there it will run right , he's built 4 -5 v6 hi perf. Mercury's for me, over the years, all ran perfect up til the day's I sold them, he has 2 of my big motors up there now, and did the tuneup on my '01 pro kicker, it's the most dependable 15 hp 2 stroke i've ever owned, i got rid of a honda 15 4 stroke for that sweet little merc.,best Mercury shop around,