5.7 cuts out at high speed when using trim

[tool39]

I have a 88 5.7 260 HP mercruiser that cuts out at high RPM. When I attempt WOT and use the trim it seems to cut the engine out, almost as if it's robbing power from the ignition system. I checked the connections on the trim pump, all tight, battery's new, 14 volts on the gauge when under way. The trim works fine the rest of the time. I only have the problem at WOT. Any ideas?

 

[airman]

Re: 5.7 cuts out at high speed when using trim

Does the engine regain power once you've trimmed it out? Maybe your coil is getting edgy.

 

[tool39]

Re: 5.7 cuts out at high speed when using trim

It only happens when pressing the trim button, almost like a dead short. Only at WOT.

 

[damie]

Re: 5.7 cuts out at high speed when using trim

i just had same problem yesterday!!<br />had to be towed in,i found on closer inspection that main 30a fuse in fuse box had corrosion on it and was arcing under load(when pressing tilt switch)and so killing all other power,apart from the feeds taken direct from battery.<br />this melted fuse!and caused total power failure to accesories including ign switch supply.<br />hope this helps.