Merc 125 making funny knock at 4000+ rpm

sixstring531

Seaman
Joined
Jun 6, 2007
Messages
62
Re: Merc 125 making funny knock at 4000+ rpm

Well, made an appointment at a reputable dealer/service marina on Truman lake. Further away, $20 more and hour, but at least everyone is certified for my brand! :) Not yelling, just exhausted from all the calling and shelling out of greenbacks for jobs not done.
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: Merc 125 making funny knock at 4000+ rpm

Well, made an appointment at a reputable dealer/service marina on Truman lake. Further away, $20 more and hour, but at least everyone is certified for my brand! :) Not yelling, just exhausted from all the calling and shelling out of greenbacks for jobs not done.

I hear ya.. be careful though.. if you get mad enough you'll end up with a shop full of tools and another very expensive hobby.:)
 

sixstring531

Seaman
Joined
Jun 6, 2007
Messages
62
Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

**UPDATE**

Took it to a certified Merc Mechanic....engine runs great, new gaskets were put on just fine, nothing wrong with the engine. The problem is the new (used) lower unit I put on it. (which I didn't tell them I did) It has a clutch spring going out, so it was unmeshing and especially on the way down (powering down, when it made the noise the whole time) it was disengaging the drive and clicking.

Good thing the lower unit has a 90 day warranty. Contacted the guy I got it from and he wants me to send it back and he will either rebuild the thing or send me another one. Good thing to know motor is good. Just more waiting.
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

**UPDATE**

Took it to a certified Merc Mechanic....engine runs great, new gaskets were put on just fine, nothing wrong with the engine. The problem is the new (used) lower unit I put on it. (which I didn't tell them I did) It has a clutch spring going out, so it was unmeshing and especially on the way down (powering down, when it made the noise the whole time) it was disengaging the drive and clicking.

Good thing the lower unit has a 90 day warranty. Contacted the guy I got it from and he wants me to send it back and he will either rebuild the thing or send me another one. Good thing to know motor is good. Just more waiting.

Hey, that's great news. I don't think you wasted any money with that gasket change since they were leaking. These things can be funny the way they telegraph noises. I'd have never thought L/U from the description but that's not an excuse, I should have asked.
 

pigeon laker

Seaman Apprentice
Joined
Jun 19, 2008
Messages
47
Re: Merc 125 making funny knock at 4000+ rpm

Glad to see your problem was fixed.I have a similar problem where #4 plug always looks new(merc 115).Lost a bit of power and rpms.Could my problem be this same gasket?
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Merc 125 making funny knock at 4000+ rpm

Glad to see your problem was fixed.I have a similar problem where #4 plug always looks new(merc 115).Lost a bit of power and rpms.Could my problem be this same gasket?

Yep.
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

**UPDATE**

Took it to a certified Merc Mechanic....engine runs great, new gaskets were put on just fine, nothing wrong with the engine. The problem is the new (used) lower unit I put on it. (which I didn't tell them I did) It has a clutch spring going out, so it was unmeshing and especially on the way down (powering down, when it made the noise the whole time) it was disengaging the drive and clicking.

Good thing the lower unit has a 90 day warranty. Contacted the guy I got it from and he wants me to send it back and he will either rebuild the thing or send me another one. Good thing to know motor is good. Just more waiting.


That's a characteristic clicking noise that any experienced merc mechanic should have been able to pick up on when on the lake. Most, if looking for a click would have put it into gear, walked behind the trailer and kicked the prop, watched it ratchet for 4 turns, and said, "that ain't quite right".

Glad you found a mechanic.
John
 

sschefer

Rear Admiral
Joined
Nov 13, 2008
Messages
4,530
Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

Re: Merc 125 making funny knock at 4000+ rpm **UPDATE**

That's a characteristic clicking noise that any experienced merc mechanic should have been able to pick up on when on the lake. Most, if looking for a click would have put it into gear, walked behind the trailer and kicked the prop, watched it ratchet for 4 turns, and said, "that ain't quite right".

Glad you found a mechanic.
John

Just for info, another way is to run up to about 15mph then turn the key off in gear and listen. If it ratchets you have bad dogs. Either way works.
 
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