2005 60hp 4stroke bigfoot won't go over 3,000rpm

michaelj1978

Seaman
Joined
Jul 8, 2004
Messages
50
Hi there. I'm looking to purchase a 21ft Tracker fishin barge with a 2005 60hp Mercury "Bigfoot" 4 stroke motor. I water tested the boat yesterday. Started and idles great, pees good. We got the boat out in the open and at full throttle it was running 3,000rpm and 9-10mph. The motor wasn't struggling, it just seemed that it ran out of throttle since the lever was pushed down all the way. I know these motors should run in the 5,500 range and on a 21ft should be able to hit 15-20mph with 2 people on it. It was running an 11 pitch prop 77338CP1P11 was etched in the prop.

The motor also needs a new starting solenoid, very cheap, but I don't think that could be the problem. The owner did have a repair bill on a ground that burnt up but it was fixed and a new wire on it. No noises or beeping from the motor so I don't think it was in limp mode even though it couldn't get up to speed/rpm. I'm taking the boat to a repair shop to have them look it over and see what's wrong but it'll be 2 weeks before I can get it in. Does anyone have an idea so I can troubleshoot at home in the meantime?



Any experience with this before and any idea where to start? Thanks!!!
 

JimS123

Fleet Admiral
Joined
Jul 27, 2007
Messages
7,952
It would be my guess that its not running on all 4 cylinders.
 

michaelj1978

Seaman
Joined
Jul 8, 2004
Messages
50
That was my thought too. I was doing a little more research and there appears to be a recall on the coil packs or something related to the ignition. I'll mention this to the shop when I take it in and have them go over it.

Question. Would having it only run on 2 or 3 of the 4 cylinders cause any damage? The older couple I got it from said it ran just fine, but it obviously wasn't developing max power or hitting the max rpm range where it should be.
 

michaelj1978

Seaman
Joined
Jul 8, 2004
Messages
50
I don't have access to it now but it should rev further in neutral with no load even if a cylinder isn't getting spark, correct?
 

Mohawkmtrs

Chief Petty Officer
Joined
Jan 13, 2010
Messages
561
Perform a cylinder drop test or put a timing light on each spark plug wire or get a $10 adjustable spark tester.
 

wn6ngp

Petty Officer 1st Class
Joined
Aug 12, 2012
Messages
209
In the old days on 2 strokes if 1 cyl did not get adequate fuel then there was a chance that one cylinder might get ruined. I would assume on 4 strokes with fuel injection that wouldn't be an issue. One check would be to remove the plugs and just compare. Whenever I had problems like this I've always been able to tell because the plug in the poorly behaving cyclinder would look different. then obviously while they are out its a good time to check the compression.
 
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