1997 Mercury 60hp, Loss of power, rough idle, stalls

Hi Everyone,

I have a 1997 Mercury 60hp, 3 cyl outboard and I seem to have gradually lost power, now it does wide open at about 3,000 RPM if that, and it will not plane. This problem seems to have gradually appeared. Some things I have done:

Changed the spark plugs- the old ones seemed a little blackish, but not overly worn and not fouled badly either. This caused the motor to work a little better, but not that much, and when I throttled up, it seemed to come up on throttle then it kinda dropped rpm and stayed that way.

Pump the primer bowl while WOT- had no effect, seems like we have good fuel flow?

Removed spark plug wires one at a time- runs although not smoothly with the bottom and top ones removed, if you pull the middle one, it doesn't run at all?

Tied the boat to the dock and ran full open- if you do this, the boat tops out at ~2200 rpm and stays there, if you try to come up to this load condition quickly, it will stall the motor.

The motor kinda sounds "clanky" while it's running any ideas??? Please help.

Thanks,

Al

Re: 1997 Mercury 60hp, Loss of power, rough idle, stalls

Anyone?? Please help....

Re: 1997 Mercury 60hp, Loss of power, rough idle, stalls

I'll chime in since the experts haven't gotten to you yet. Take a proper compression test and check spark with an actual spark test. I'm not familiar with the ignition on your motor but you need a hot, blue spark to jump at least a half inch gap, perhaps more.

Re: 1997 Mercury 60hp, Loss of power, rough idle, stalls

Could be any number of things.

I agree with the compression and spark test.

Next you could try pulling the plug wires one at a time and checking the spark plugs. If you don't have the stomach for it just buy a new set of plugs install them and see if that was the problem.

Re: 1997 Mercury 60hp, Loss of power, rough idle, stalls

I've installed a new set of sparkplugs are part of my initial trouble shooting, the old ones were wearing, but they were ok. It ran a little better with the new ones, but still had the same problem. The "tied to the dock" test was with the new plugs, as was the RPM drop. I did a compression check about two months ago as part of my regular maint by the mech. How do I check spark? Any other ideas?

Re: 1997 Mercury 60hp, Loss of power, rough idle, stalls

just a long shot here, but I bought a 1998 60 triple that ran like garbage until I re-built the carbs. They had gradually gotten gummed up with old fuel.

Re: 1997 Mercury 60hp, Loss of power, rough idle, stalls

YakAtak said:

I've installed a new set of sparkplugs are part of my initial trouble shooting, the old ones were wearing, but they were ok. It ran a little better with the new ones, but still had the same problem. The "tied to the dock" test was with the new plugs, as was the RPM drop. I did a compression check about two months ago as part of my regular maint by the mech. How do I check spark? Any other ideas?

Click to expand...

Go to your local auto parts store and buy a spark checker. The tester will ground to the powerhead and will connect to the plug wire. Costs about $10.