Mercury 9.9 Troubleshooting

[davemcgrory]

Hey everyone. Having some issues with my Mercury 9.9 outboard, looking for some insight. I am not much of a mechanic, but I am a fast learner...
1) Recoil neutral interlock is giving me issues when pull starting. I have to take the top cowl off, disengage the recoil lock, then it allows me to pull. Is there a trim adjustment that can be tweaked? Or should I remove the interlock all together?

2) My electric start will not work off of battery power. I press it and nothing happens. When plugged into shore it works fine, but when I'm out in open water I always need to pull start. Any obvious solutions? My batts have proper voltage...

3) Most distressing issue is the motor putters out randomly when either idling or when in gear at low throttle. Having trouble diagnosing, when back in the slip I ran it with no issue at idle for 15 min with no issues.

Any advice would be appreciated!

[Muckle Flugga]

Originally Posted by davemcgrory

Hey everyone. Having some issues with my Mercury 9.9 outboard, looking for some insight. I am not much of a mechanic, but I am a fast learner...
1) Recoil neutral interlock is giving me issues when pull starting. I have to take the top cowl off, disengage the recoil lock, then it allows me to pull. Is there a trim adjustment that can be tweaked? Or should I remove the interlock all together?

2) My electric start will not work off of battery power. I press it and nothing happens. When plugged into shore it works fine, but when I'm out in open water I always need to pull start. Any obvious solutions? My batts have proper voltage...

3) Most distressing issue is the motor putters out randomly when either idling or when in gear at low throttle. Having trouble diagnosing, when back in the slip I ran it with no issue at idle for 15 min with no issues.

Any advice would be appreciated!

I had a Merc 9.9 for nearly 2 years on a boat a few years back. It was memorably the worst outboard engine I have known in my whole life. So bad that I nicknamed it the "Antichrist" and finally traded it in (somewhat shamefacedly as it was so bad) for a Yamaha when it began delivering shocks through the tiller arm. I swear that thing hated me. After a while the feeling was mutual. I found the build quality awful, I found you had to play the choke like a violin to keep it running, and in doing so half the time the damn connecting rod for the choke plunger would fall out. Etc etc.

I am very sorry to have no better advice. It is just that when I saw the words Mercury 9.9 Troubleshooting it evoked some bad memories. Good luck… and if you feel it is out to get you… it probably is!

[Muckle Flugga]

Actually I have just noticed this is your first post on the forum. I am sorry for the grumpy response. Welcome to the forum and do accept my apology. I will leave it up as it was actually meant. However there is no reason to think that your engine is the same as mine was based on a sample of one.

[GordMay]

Greetings and welcome aboard the CF, Dave.

[Muckle Flugga]

One piece of perhaps useful advice I can give you is please do not remove the interlock. It is there as an important safety device. If you start the engine in gear and are not prepared for it to go, you could severely injure yourself or someone else.

[four winds]

Sounds like all your issues could be the result of a weak/bad battery.

How old is your battery?

An old worn out battery can seem to have decent voltage yet no real usable power.

[davemcgrory]

Batts are 3yrs old with not much hours drawing off them. Just have them on Battery Tender trickle charge

[davemcgrory]

Thanks GordMay!

[davemcgrory]

Originally Posted by Muckle Flugga

One piece of perhaps useful advice I can give you is please do not remove the interlock. It is there as an important safety device. If you start the engine in gear and are not prepared for it to go, you could severely injure yourself or someone else.

Copy that. Any ideas on how to make it engage while in gear but disengage when in neutral? Thanks

[davemcgrory]

Smells like I have fuel in the oil. Would draining it and putting new oil in it be sufficient? Or should I have a mechanic check it?

[davemcgrory]

Dipstick has strong gas smell

[a64pilot]

It's called "making oil" pretty common on four stroke outbaords, fishermen that troll a lot often have this problem, changing the oil is indicated, but with all your problems, maybe a mechanic is not a bad idea.
Usually fuel diluted oil is discovered because the oil level is increasing


Sent from my iPad using Cruisers Sailing Forum

[SVFruitBat]

I'm having a similar issue with a 2010 Merc 9.9 four stroke outboard on our dinghy. seems to always hit a dead spot when engaging the engine in forward that causes it to die before the throttle gives it enough gas. if you throttle up quickly to prevent this, it can mean a startling or even dangerous jerk forward when you take off.

i've tried upping the idle set screw, but it doesn't seem to change how low it goes during the engagement process.

let me know if you've figured anything out!