Mercury 9.9 won't start for the life of me... what's next?

[Shrew]

A weird thing that sometimes happens with mine. I need to yank the emergency landyard, then pull the emergency stop all the way out, then re-insert the emergency lanyard.

It's as if the shutoff shorts the contact. Once removed, pulled out and re-inserted it properly breaks the short and allows the engine to start.

If it doesn't start after 4-5 pulls, I do this and it starts first pull.

[liquidice]

Originally Posted by thomm225

Besides all the "normal" engine fixes how about the stranger ones:

Is your shut off switch "thingy" in place?

I lost mine and have some leech line holding the switch in the "on" position.

Sometimes I have to retighten the line when the engine won't start

A frequent occurrence on motors new enough to have one. Also an easy fix. Gorilla tape can hold it shut to confirm the diagnosis.

[dfloeter]

My former Nissan 9.8 did the same thing when we were on Andros near the US Navy base. I had torn the carb down and cleaned as well as possible on the dock and the base engineer even took it to the shop and soaked and blew out everything. Still no good. Finally an email to a Tampa Nissan dealer led me to jet, I believe, 6-A, way down in the bottom and it had a tiny piece of dirt partially blocking the passage. A previous posters advice to check all jets with a wire is spot on but this one took some looking to find. Get the schematic and find that jet. A few months later a friend with the same engine had this issue and we fixed it at the Hamburger Beach dinghy dock.

[thomm225]

Originally Posted by Cool Hand Luke

Thanks for all the input, guys!!

I will try all of the above tomorrow morning when I go back to the marina. The engine was sitting on the side for a couple of months while I was sailing from the BVIs to Florida to New Jersey. I think I had it laying on the wrong side (these engines are supposed to lay on the handle, right?) since the handle was on top.

I'll take a look tomorrow and post some photos, too. I really appreciate everyone giving me their two cents on this issue!!

Yes, it should be stored tiller down......

[Billnpr]

KISS, not recommended by many because of no lubrication, get a can of starter fluid from any store . Spray it in the carb , and it should fire up. Now you know that it is a carb issue. Proceed to clean low speed jets.
If I don't run my Yamaha 8, 4 cycle often, the low speed jet clogs. I use ethonal and run the carb dry. The manufacturer fuel filter before the carb and the low will still contains small drops of fuel which evaporate. The evaporated fuel takes the form of dandruff size flakes which of course clog the low speed jet. Solution is to run once a month in a can or in the water or clean the Jets.

[thomm225]

Originally Posted by liquidice

A frequent occurrence on motors new enough to have one. Also an easy fix. Gorilla tape can hold it shut to confirm the diagnosis.

Mine has to be held open/pulled for the motor to run.......that's why I have the leech line tied on where the clip used to be. I tied it on in 2012

My engine usually starts (are attempts to start) somewhere between 4-8 pulls even when it hasn't been used for a month or so.

My carburetor has never been cleaned and I don't run it dry after use but do treat the fuel from time to time

[thinwater]

"KISS, not recommended by many because of no lubrication, get a can of starter fluid from any store . Spray it in the carb , and it should fire up. Now you know that it is a carb issue. Proceed to clean low speed jets."

^^Smart trouble shooting step.

"If I don't run my Yamaha 8, 4 cycle often, the low speed jet clogs... Solution is to run once a month in a can or in the water or clean the Jets"

^^ Even in the winter, even if I decide it is too ugly to go out, I run the engines every month, in gear at mid-throttle at the dock, for 15 minutes to circ the oil and burn through a little gas. Easier than chasing problems.

[JOHNMARDALL]

I have a Mercury 9.9 and it was great in all respects until one day it didn't want to start or run at low speed. The little internal plastic connector had fallen off the shaft of choke/slow-run pull button. Replaced it and motor went back to happy normal. Could your problem be that simple?

I hope so
John Mardall
Vetus Maxwell Group.

[UFO]

Originally Posted by Cool Hand Luke

Thanks for all the input, guys!!

I will try all of the above tomorrow morning when I go back to the marina. The engine was sitting on the side for a couple of months while I was sailing from the BVIs to Florida to New Jersey. I think I had it laying on the wrong side (these engines are supposed to lay on the handle, right?) since the handle was on top.

I'll take a look tomorrow and post some photos, too. I really appreciate everyone giving me their two cents on this issue!!

Been there done that (Laying wrong side) - Oil back flowed from the engine into my Carby and it would not start for love nor money - Just take the carby apart and clean out with carby cleaner - I'd do the jet whilst there as well

[Red Sky]

Originally Posted by UFO

Been there done that (Laying wrong side) - Oil back flowed from the engine into my Carby and it would not start for love nor money - Just take the carby apart and clean out with carby cleaner - I'd do the jet whilst there as well

If it's been laying on the wrong side, it's oil in the carb. I did it once when moving it from the house to the boat ramp. I pulled and pulled, no go. Luckily, the owner of the Outboard Motor Shop in Oakland was in the process of putting his own boat in the water and offered to help. There's a small slotted screw plug on the side of the carb. He backed it out, drained the oil trapped in the carb and reinstalled the plug. A couple of pulls and it started right up.

[chris95040]

Stuck needle valve?

Sometimes, even though the carburetor bowl has emptied and float has dropped, the needle is still stuck in the hole preventing fuel from flowing in.

Before taking anything apart, try tapping hard on the side of your carburetor with the handle of a screwdriver.

Oh, and even before that, if you've got a fuel shutoff valve, make sure you remembered to open it.

[GazzaAntipodes]

Could be the fuel mate.
From my experience Outboards will not run on anything under 93 , and will not run on ethanol or blended fuels. I use 95 and do not have issues starting, could be worthwhile looking at before pulling it all apart

[hellosailor]

FWIW, octane numbers are computed very differently around the world. So what you call "93" in Oz is probably "87", the standard pump gas in the US. The numbers are meaningless unless you know which system is being used.

Three months after the original post, one can only assume the OP dumped his engine, was promptly arrested for engicide, and hasn't posted any results because they don't let him have internet access in prison.

[GazzaAntipodes]

Good point

[Antares]

I had the same problem with my Merc 9.9 four stroke. The cause in my case was a cogged carb caused by old fuel with water in the tank. The solution was to dissasemble the carb and clean all the jets and passages with aerosol carb cleaner. I also drained the tank and made sure there was no water in it.

The four strokes do not tolerate any contamination in the fuel. It wasn't particularily difficult to clean after watching a youtube video made by a Canadian. He pointed out the "hidden" jet under a small plug. After cleaning all was well and starting was back to 2 or 3 pulls.