90 Merc 4 dies when trimmed up or down

[worknpro]

I have a 2000 Merc 90 4 stroke that will run ok at idle, develops a slight miss when the throtle is increased, and dies completly when trimed up or down. This happens even after I have quit trimming, so the trim is not pulling a charge. It doesn't take much trim to kill it. Last time out I couldn't take it much above idle to get back in. This is my second Merc 90 4 stroke that I have had problems with. Dealer could not fix and replaced the first engine with this one. Here we go again. Any ideas?

 

[Valv]

Re: 90 Merc 4 dies when trimmed up or down

I am no expert, but could be motor is not charging battery, thus runs out of it's own generator, which looks like is not working either and you are running it from almost dead battery. Have you checked connections, crossed any cable, etc.

 

[steelespike]

Re: 90 Merc 4 dies when trimmed up or down

I would look for a gas line being pinched or a connector or wire rubbing or losing connection.<br />Maybe some sort of safety switch Possibly a ground<br />losing contact. Is the tilt trim indicator <br />causing some sort of problem.<br /> Are you running the original controls or the <br />new motors controls,maybe something there.<br /> If injected maybe the pump is being affected<br />somehow if Carburated maybe a float problem.<br /> Have you done a search on the net for a report on this or a forum on merc trouble shooting?

 

[OBJ]

Re: 90 Merc 4 dies when trimmed up or down

Hey worknpro....<br /><br />Just one more thing to try....<br /><br />With the motor at idle, crab the wire harness near where it enters the engine and move it in a manner to corepond with the movements when you use the trim/tilt. Could be a broken wire in the harness making/breakin' contact.