2005 mercury 90hp 4 stroke

[sabaka]

I'll give you the facts after I explain the problem! I turn on the key and the motor turns over properly;;;; let go of the key and then ; nothing . It does not fire . Facts;;;; it has spark ;;;; it's not the kill switch because there is no spark when lanyard is removed;; the fuel pump is working ;;; the carbs are working;; while the key is held on and my helper opened the carbs , the motor rev'd up ;;;; while he had it reving and I let go of the key , there was nothing again! It's not a starter problem;; nor a fuel problem . The fuses are ok . There is exhaust smoke. It sounds like it's actually running while I hold the key on . Worked fine a month ago ; the, last week this problem !!!!!! HELLLPPPP PLEASE !!!

 

[sutor623]

Re: 2005 mercury 90hp 4 stroke

Do you have a warm up lever on that motor? Something to give the motor a little gas as it starts.

 

[sabaka]

Re: 2005 mercury 90hp 4 stroke

No warm up lever ;;;;; getting adequate gas ! Thanks for your input ;;;;;; keep em coming folks !

 

[woody66912]

Re: 2005 mercury 90hp 4 stroke

Unplug the main harness at he engine and jump the starter solenoid, this will check the key switch. If it stays running plug the harness back in to kill it.

 

[sabaka]

Re: 2005 mercury 90hp 4 stroke

Unplugged the main cable;; jumpered the starter solenoid;;;; turned over but did not run. This time however ; it sounded much different. Before; with the key; it sounded like it was running while I was turning it over. This time it sounded like the typical sound you would expect from the starter motor;;;;;;;;;;;;; are you following me!!!!????? Thanks for everyones' help

 

[woody66912]

Re: 2005 mercury 90hp 4 stroke

Drain the carbs, try to catch the fuel look for water. Some times when you drain them you can see water running around in the engine pan.

 

[sabaka]

Re: 2005 mercury 90hp 4 stroke

Drained the carbs several times . As I mentioned earlier ; engine reved up as per normal when I held the key on, and my helper opened up the carbs via the linkage. Now I have one more scenerio to add;;;;;;; the main cable coming from the boat ( at the connector at the motor) has two wires hanging out. They are about 6 inches long ; one brown/white, with a male connector;;;;; the other brown , with a female connector. I assumed they are for some sort of accessory. Fearful of joining them togeather in case I damage some sort of electronics in the motor . There are no mating wires beyond the connector for them to connect to.

 

[woody66912]

Re: 2005 mercury 90hp 4 stroke

Don,t worry about the wires. I starting to think you have some plugged low speed jets. If you can get it to rev up by opening the throttle plates, then what you are doing is jumping the low speed circuit and getting on the main jet. One more thing you can try to check this is, while starting, spray carb clean in the air box if it tries run then it's a fuel delivery problem.

 

[Don S]

Re: 2005 mercury 90hp 4 stroke

No warm up lever ;;;;; getting adequate gas ! Thanks for your input ;;;;;; keep em coming folks !

I think he meant to give it some throttle, not more gasoline. So the engine runs a little faster while it warms up.

Has any work been done on the carbs, any mixture adjustments? Have you checked the enrichment valve to see if it's working?

http://boatinfo.no/lib/mercury/manuals/75-90.html#/176

 

[woody66912]

Re: 2005 mercury 90hp 4 stroke

WOW Don, what a manual site. Now i don't have to keep going out to the garage.

 

[sabaka]

Re: 2005 mercury 90hp 4 stroke

Well; now that we are talking about work on the carbs; we have ventured beyond my technical capabilities !!!!!! I was really hoping for a simple miracle ;;;; therefore I have no choice but to make a very expensive trip to the shop ! Thanks for all your help folks !!!!

 

[sabaka]

Re: 2005 mercury 90hp 4 stroke

Tried the carb cleaner into the air intake ;;;;;;;;;;; didn't do anything !!!! A guy could become wealthy if he he could invent a fool proof outboard and fool proof trailer lights !!!!!

 

[sabaka]

Re: 2005 mercury 90hp 4 stroke

Hey folks ;;; thanks again for your input. The motor is in the shop now. Suspect problem now is one of two;; either a blown head gasket or cylinders 3&4 have their rings carboned up resulting in low compression readings.