90hp mercury loosing power

[75starflight]

I am asking for a friend of mine here in nebraska. Just purchased a 1985 90hp 6cyl mercury on a fishing boat. motor starts up ok and idles ok. when cruising anything above 2000rpm the motor looses power and bogs down, but it also tries to go. He says it acts like it is loosing spark or not getting enough fuel.

Any ideas would be helpful.

[Plugcheck]

Main jets clogged up, or dizzy not advancing correctly.  Clean carbs and do a link and sync.

[Plugcheck]

Might check for choke opening correctly, would cause same issues.

[fireman24mn]

Check fuel vent in tank.

[Rich_V174SS]

My take on it could be a weak fuel pump, clogged fuel tank vent or other fuel line restriction (bad primer bulb). A bad stator under the flywheel can give you the same symptoms if the coils are breaking down.

[higgins]

It's your Stator

[75starflight]

My friend after seeing all of your advice is going to replace the stator.

Thanks all!

[DL-North]

In our case, on a 1976 850, it was the switch box. Started, ran great up to about 2000 rpm, fell on it's face above 2000.

Dan

[dorelse]

So, based on this thread...essentially...replace everything.

[75starflight]

So, based on this thread...essentially...replace everything.

He is contemplating this also.

Gregg, sent me the link to the repair manual for it also. So he has it now to help.

[dorelse]

Not sure I'd have started with the stator...eliminate the easy first...then start changing parts.

[Hyperacme]

"eliminate the easy first"

Yep ... Take Rich's advice ...

"My take on it could be a weak fuel pump, clogged fuel tank vent or other fuel line restriction (bad primer bulb). A bad stator under the flywheel can give you the same symptoms if the coils are breaking down."