Hard to star & keep running Merc 9.9

Chris in Indiana

Petty Officer 3rd Class
Joined
May 29, 2008
Messages
82
Hello,
I've got a 1989 Merc 9.9 that I just bought in Indiana and had shipped to my new home in Monterrey Mexico. I was told that it runs very well but has not been started in about 3 years. So, I replaced the water pump and tried to crank it up yesterday. I turned the idle speed all the way up, pulled the choke knob out and she started right up, ran for about 30 seconds and died. Then wouldn't restart. I pulled the plugs and they looked all gummed up with unburnt fuel/oil. After cleaning and reinstalling the plugs the motor would crank right up, run for about 30 seconds and die. Any ideas? Incidentally the motor only runs with the choke on, the second I push the knob in it dies.
 

Karl_Childers

Petty Officer 2nd Class
Joined
Mar 2, 2009
Messages
118
Re: Hard to star & keep running Merc 9.9

Most likely a carb problem. Pull the carb and clean the heck out of it. In my opinion, there is only one acceptable method for cleaning spark pluggs: throw them away and buy new ones

Good luck
 

Chris in Indiana

Petty Officer 3rd Class
Joined
May 29, 2008
Messages
82
Re: Hard to star & keep running Merc 9.9

Well, I fiddled with it some more this morning and agree the carb needs attention internally. Drat! It takes too long to get a manual shipped down here and I really don't want to tear into it without one. I've gone down that road before and it didn't work out too well. A friend of mine mentioned a boat shop near by it turns out their a Merc dealer. So, I dropped it off and we'll see what happens. I don't speak much spanish but I think I got the point accross that I want it to run when I get it back.
 

Chris in Indiana

Petty Officer 3rd Class
Joined
May 29, 2008
Messages
82
Re: Hard to start & keep running Merc 9.9

Re: Hard to start & keep running Merc 9.9

Just a follow up. I got the motor back from the dealer (Powerboats, Mexico) last Friday and it turns out the carb was very dirty and the water pump wasn't working properly despite the fact that the impellor was new. She runs like a dream now! Starts running before the end of the first pull! The mechanic put about 10 hours of time into it and the total bill was only about 45 bucks US. If anyone out there winds up in Monterrey Mexico and is in need of a good outboard mechanic I definitely recommend Powerboats (powerboats.com.mx) Their sales people speak English and don't mind translating to the mechanics.
 
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