Guests - If You want access to member only forums on FM. You will gain access only when you Sign-in or Sign-Up on Fishing Minnesota.

It's easy - LOOK UPPER right menu.

Sign in to follow this  
Followers 0
blakjack23

'99 Mercury 90hp problem....HELP!

9 posts in this topic

Hi everyone, I decided to take the boat out last night to get some fishing in but it didn't turn out too well. I launched the boat, started the engine as usual, slowly left the launch and about 50 yards out it died. After that I could start it, but anytime I put it in gear and gave it a little gas it died again. I could also start it while having the throttle on full (out of gear of course), it would start and right when it would start getting rev'd high I would pull back on the throttle and it would die again. The bulb it hard and water is coming out of the pee hole. There is also plenty of gas and oil. Any idea's? She has been running great all summer until now.

Share this post


Link to post
Share on other sites

Verify spark on each cylinder. Sounds like the carbs and the fuel pump need to be rebuilt

Share this post


Link to post
Share on other sites

My buddies dad has a 75 merc and his motor does the exact same thing until warmed up good. We have to sit at the landing for a good 5-10 min letting it warm up before we can think of taking off.

Sounds dumb, but did you give it plenty of time to warm up? With the summer winding down, the water is colder along with the air temps and it might take an extra few minutes to get up to operating temps.

Share this post


Link to post
Share on other sites

Sounds like a collapesed (sp) fuel line...

Share this post


Link to post
Share on other sites

I would say fuel starvation, could be dirty carbs or bad fuel pump. Try to start it and see if it keeps running while pushing key in (choke).

If it gets better then your carbs needs cleaned or rebuilt.

Share this post


Link to post
Share on other sites

Mine started doing that a bit last year but didn't think much about it at the time.

This year, I needed to get the carbs cleaned...

Share this post


Link to post
Share on other sites

Check the fuel filter, check spark, etc.

Also make sure you don't have water in your gas. I had a problem this summer with my boat starting on full throttle and then cutting out as I dropped the RPM's down. I was suspecting the carbs, but turns out I had a bunch of water at the bottom of the tank. Too bad the dealer figured that one out!

Share this post


Link to post
Share on other sites

WHAT KIND OF GAS DO YOU USE? TRY PREIMIUM AND ADD A CAN OF SEA FOAM TO 20 GALS OF GAS OR HALF CAN TO 10 GAL OF GAS I DO THIS WITH MY 2002 9O AND SHE RUNS LIKE A TOP YOU WILL NOTICE TOP END IS MUCH BETTER TWO. GOOD LUCK. DAN

Share this post


Link to post
Share on other sites

Does it come to life when you hit the choke just before it dies? I have a merc 90 2002 model. Does the same thing. Been to the shop for a checkup. All was fine. I concluded its just cold blooded! Mine comes to life when i hit the choke! sure is irritating specially when the ramp is busy!!

Share this post


Link to post
Share on other sites
Guest
This topic is now closed to further replies.
Sign in to follow this  
Followers 0



  • Posts

    • monstermoose78
      Seen some fox tracks where I was looking for birds yesterday so I might have to head out there after dark.
    • monstermoose78
      Went out yesterday after the wake and visitation with Finn. He flushed two hens and I saw him chasing a rooster but I am not fast enough to keep up. It flushed about a hundred yards out from me. We seen one grouse but it flushed 60 yards in front of Finn and he was only 10 yards infront of me. Then Finn started going crazy so he headed into the cat tails and wow 50 or so mallards flew at me and then 7 big swans. Finn did not look happy that I just watched them. It was a fun little trip.    Anyone else Lise out there chasing birds yet?
    • PSU
      Quick question, we have never come up in the winter, but it's my understanding the ice is usually questionable around Oak Narrows and Timbuktu. Does anyone know what the ice is usually like in Birch Narrows (West Hinsdale) and Smarts Bay (SW area Hinsdale) around the Retreat Lodge Area which is where our island property is.   Thanks for any insight
    • monstermoose78
      As of yesterday most lakes are froze over please watch for areas that geese and swans have kept open. I checked a lake and found about an inch yesterday and I am sure it made some more last night. 
    • Surface Tension
      U-Haul in Hermatown will fill a tank and you pay for what they put in.