1990 force 90 Ldrive bogs at 3/4 to wot

[robert301972robert]

Ibought this boat with a bad motor. So i went and bought a 1990 90 hp outboard I took the power head off and put in on my ldrive. I took it out for a test run. And it did great. It would top out about 35mph I had no problem out of it. So i took it up to dock and shut it off. loaded it on the trailer. the next day i took it back out and now i can only get about 3000 rpms out of it. It will not plane out it goes about 15mph. I have put new plugs in it. cleaned the carbs with new needles. Put a new fuel pump on. did a compression test on it 120,120,120. Every once in a while it will surge in power all most like it wants to go. It does not do that very offten most of the time it just wont go. the primer ball is allways hard even at wot. wene i have it at wot i can squirt a little gas in to the carbs. And the motor wants to die. so it is not a lack of fuel. at wot i can engage the choke and the moter wants to die. so the chokes are working fine. the butterflys are opening all the way up. but wene the motor is cold and i go to start it the chokes do not work. I have to use staring fluid. every ocne in a while wene i go to start it cold or warm it will grunt Is that normal. i have done evry thing i can think of to fix the problem. The next thing to look at is the electronices. could it have a bad stator or trigger or bad power packes. I just thought of something else wene it runing good my brother noticed the the insalation and the platice that covers the insalation. stated to get sucked into the carbs. can that cause the problem i am haveing if it got stuck on the reed valves? UPDATE on the reed valves I just checked them they are fine nothing in them they seam to open and close just fine.

 

[jerryjerry05]

Re: 1990 force 90 Ldrive bogs at 3/4 to wot

Sounds like the fuel system.Clean the carbs,rebuild the fuel pump.
Check the spark?
If you changed the powerhead did you check the timing?

You should never have to use starting fluid on a outboard,unless your not doing something right.

Take a breath when asking questions.
Make short paragraphs,it's REALLY hard to read and retain anything when it's bunched up like that.

When you check the electrical.The wire connectors have been sealed in shrink tube.They can break and still look great.
Change them as you work on the motor.
I was checking a trigger and it tested bad.I was unhooking it and the connector came apart in my hand.Not a bad trigger,a bad connection.