9.9 merc issues

Anything and everything related to boating, motors, and electronic equipment. Find out the answers to your questions here.
Post Reply
User avatar
andrew1234
Participant
Participant
Posts: 95
Joined: Mon Sep 13, 2010 9:53 am

9.9 merc issues

Post by 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
User avatar
Bass assassin
Bronze Participant
Bronze Participant
Posts: 157
Joined: Fri Apr 22, 2005 7:09 am
Location: Kanata

Re: 9.9 merc issues

Post by 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
User avatar
Yakster
Bronze Participant
Bronze Participant
Posts: 101
Joined: Thu Dec 12, 2013 8:41 pm

Re: 9.9 merc issues

Post by Yakster »

Clogged jets in the carb.
Call Dave at Aim Marine.....just got mine back and it's like I have a new motor.
User avatar
toobinator
Gold Participant
Gold Participant
Posts: 1354
Joined: Thu Nov 07, 2002 10:50 pm
Location: Winchester Ont.
Contact:

Re: 9.9 merc issues

Post by 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
Save a bass. Eat a chicken
User avatar
andrew1234
Participant
Participant
Posts: 95
Joined: Mon Sep 13, 2010 9:53 am

Re: 9.9 merc issues

Post by andrew1234 »

Ed, ha ha! Yes gas tank was vented
User avatar
andrew1234
Participant
Participant
Posts: 95
Joined: Mon Sep 13, 2010 9:53 am

Re: 9.9 merc issues

Post by andrew1234 »

Yakster wrote: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?
User avatar
Yakster
Bronze Participant
Bronze Participant
Posts: 101
Joined: Thu Dec 12, 2013 8:41 pm

Re: 9.9 merc issues

Post by 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.
User avatar
andrew1234
Participant
Participant
Posts: 95
Joined: Mon Sep 13, 2010 9:53 am

Re: 9.9 merc issues

Post by andrew1234 »

OK thanks yakster. I'll take your advice!
User avatar
smitty55
Gold Participant
Gold Participant
Posts: 1684
Joined: Mon Jun 23, 2008 8:37 pm
Location: Lanark County

Re: 9.9 merc issues

Post by 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
Smitty

Straight shooter
User avatar
Kerrazy
Silver Participant
Silver Participant
Posts: 531
Joined: Fri May 24, 2013 4:49 am
Location: Gatineau

Re: 9.9 merc issues

Post by 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.
Kerrazy

"Everyone should believe in something. I believe I'll Go Fishing!"- Thoreau
I'd like to thank my sponsors:
Interac - Be in the Black
Jerry, my neighbour, who foolishly leaves his shed and truck open, so I can try all the latest gear!
User avatar
Roblin
Bronze Participant
Bronze Participant
Posts: 110
Joined: Sun May 12, 2013 11:05 am

Re: 9.9 merc issues

Post by 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.
User avatar
Georges
Participant
Participant
Posts: 34
Joined: Wed Mar 31, 2004 6:59 pm
Location: Buckham's bay west

Re: 9.9 merc issues

Post by Georges »

Is it pee pee water sounds like overheating check impeler
User avatar
cgates
Bronze Participant
Bronze Participant
Posts: 337
Joined: Tue Aug 25, 2009 10:00 am
Location: ottawa

Re: 9.9 merc issues

Post by cgates »

Is it sucking air from the line
User avatar
PunchRig
Bronze Participant
Bronze Participant
Posts: 124
Joined: Tue Mar 17, 2015 5:34 pm

Re: 9.9 merc issues

Post by 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,
Post Reply