Mariner Clanking noise...Pls Help...

[GeoRXT]

Its a 1996 Mariner 125hp. Left me stranded 4th of July.

It was running all good, all of a sudden a low clanking noise appeared. On the way to the ramp it became even louder and the engine itself would wiggle with the clanking sound. Now, the engine starts up right away, only when its put on forward or reverse gear it makes the clanking noise. The more you accelerate the louder the noise.

I was told it could be the clutch not engaging, the wire not adjusted or the shaft not engaging properly?

 

[Sandjob]

Re: Mariner Clanking noise...Pls Help...

Does the motor still have the same power? Sounds like you may have blown a hole through a piston. Clanks faster with engine speed? I suggest doing a compression test or at least pulling plugs and inspecting. Look for plug end gaps that are closed or damaged. Hope that isn't it -Good luck

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

I think it does clank faster with engine speed but not entirely sure as this was July 4th and I dont really remember...

I will try that and post back. Compression was near perfect about 2 months ago. If it is that, what could have caused it?

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

Well it's not the engine itself...Compression was good across the board....

Now what?

 

[Sandjob]

Re: Mariner Clanking noise...Pls Help...

Identify if it is coming from motor or lower end. Does it do it in nuetral or just in gear.

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

It does it from the lower unit...and in neutral it makes no noise at all...only when engaged in forward or reverse...

Do you think maybe the gears need to be replaced?

 

[milehighboater]

Re: Mariner Clanking noise...Pls Help...

Is there play in the prop?

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

It moves a bit when off and on neutral if Im not mistaken...The neighbour told me to put it in gear and tried moving the prop and it didnt I think, he said it was a good thing...

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

...

 

[sschefer]

Re: Mariner Clanking noise...Pls Help...

Clanking noises can be very misleading since they telegraph through the engine. If its the clutch dogs that are worn and slipping then engine RPM should increase and speed will decrease.
If it's detonation caused by an electrical ignition component failure RPM's should decrease along with speed.

Any idea if either of these things RPM/Speed things are happening?

 

[Point man]

Re: Mariner Clanking noise...Pls Help...

gear in the lower end perhaps?

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

Clanking noises can be very misleading since they telegraph through the engine. If its the clutch dogs that are worn and slipping then engine RPM should increase and speed will decrease.
If it's detonation caused by an electrical ignition component failure RPM's should decrease along with speed.

Any idea if either of these things RPM/Speed things are happening?

I remember that when I accelerated the noise would be louder and faster...Engine rpm would go up but dont know for sure how speed was because I did not want to accelerate it much since I didnt want to cause more damage...

I would think its definitely not option 2 you gave...

 

[sschefer]

Re: Mariner Clanking noise...Pls Help...

Detonation on one cylinder can cause the symptoms you describe but you would likely hear some type of backfire or popping to go along with it. I think you're probably on track with it being a L/U problem and since it is in both forward and reverse It could be a broken tooth on the main shaft drive gear but my suspicion would be bad clutch dogs. When you first shift into gear does it feel like it's fully engaged?

The problem with trying to trouble shoot this is that it doesn't make any noise when the engine is not under load. A bad wristpin or rod bearings could give you the same symptoms and transmit them down the drive shaft. I would buy a mechanics stethascope and use it to isolate the noise to the correct area. Once you know where the noise is actually originating from, trouble shooting becomes fairly easy.

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

Detonation on one cylinder can cause the symptoms you describe but you would likely hear some type of backfire or popping to go along with it. I think you're probably on track with it being a L/U problem and since it is in both forward and reverse It could be a broken tooth on the main shaft drive gear but my suspicion would be bad clutch dogs. When you first shift into gear does it feel like it's fully engaged?

The problem with trying to trouble shoot this is that it doesn't make any noise when the engine is not under load. A bad wristpin or rod bearings could give you the same symptoms and transmit them down the drive shaft. I would buy a mechanics stethascope and use it to isolate the noise to the correct area. Once you know where the noise is actually originating from, trouble shooting becomes fairly easy.

No backfire at all for sure...

I can lean towards saying that it does engages because the prop starts spinning, but definitely does not engage properly...

It does make noise when I engage it out of the water also...

 

[sschefer]

Re: Mariner Clanking noise...Pls Help...

No backfire at all for sure...

I can lean towards saying that it does engages because the prop starts spinning, but definitely does not engage properly...

It does make noise when I engage it out of the water also...

Well I have to almost laugh now when I read this post because mine just started doing the same thing yesterday. I was going along nicely, (a somewhat rare occasion for this motor), and I decided to back down to about 15mph. When I did, the lower unit started ratcheting badly. I slowed to a stop, out of gear and then resumed. Upon resuming, I started hearing a rattle at 3,300 rpm. I backed down to 3,000 rpm and headed back to the dock. By the time I got to the dock it was evident that something had let loose in the L/U and even reverse was making noise.

So, if I was to guess, I would say that you and I have nearly identical problems and there's no doubt that mine is comming from the lower unit. My second guess, without looking, says that it's probably in the clutch area but I won't rule out the main shaft gear either. At 1700.00 + I wont fix mine, because, one it's not worth it and two, I'm dumping this engine for a new E-Tec in the very near future (2 weeks). This engine has been nothing but problems for me and every mechanic that has tried to fix it over the years, (judging from past receipts).

Sorry, that's probably not the news you wanted to hear but it's truth as best as I know how to spell it out.

Just a thought to ponder, I took my boat to the shop that I'm getting the E-Tec from just to make sure I was making the right size choice (115 HO). While I was there, the comment was made that there were no E-Tec's in the shop for repair and they only had a couple of minor warranty jobs all season. All they had were Merc's. An additional comment was that as long as they keep making Merc's well always have something to fix.

That's not a slam on Merc's like it sounds. I think Merc makes as good an engine as anyone up until the E-Tec came along. Even the overpriced Yamaha's and Honda's can't compare from what I've read and heard.

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

Definitely not what I wanted to hear...I mean...I bought the boat simply because it was only $2200....the engine was in tip top shape as the surveyor (sp.) told me...Perfect compression to this day...I definitely cannot pour out $1,700 for a fix...

 

[sschefer]

Re: Mariner Clanking noise...Pls Help...

Before you let total depression set in go have it looked at by a shop. You may find that your fix is less expensive. My quote of 1700.00 is for a guaranteed replacement. You might find a cheaper used unit on ebay and yet again it might not even be your lower unit. Have it checked by a shop.

On the other hand, paying 2200.00 for a boat and motor that run perfectly is like hitting the Loto. Pretty darn rare. You should expect to lay out some cash at the onset. This is boating, its the way it works.

 

["G"]

Re: Mariner Clanking noise...Pls Help...

I think it does clank faster with engine speed but not entirely sure as this was July 4th and I dont really remember...

I will try that and post back. Compression was near perfect about 2 months ago. If it is that, what could have caused it?

Something to look at is the flex plate on the flywheel. When these things go bad/break/crack etc they sound just like a blown engine.

Just take the lid off and hit the flywheel with a hammer (easy). You'll know immediately... you may even be able to look and see the crack but there are no guarantees except that hammer test. If broken make sure you make exact witness marks on the outside ring and the inside ring before you change it out. Failure to do so will screw up your timing big time. One bolt hole off and you may have a REAL blown motor to deal with.

 

[GeoRXT]

Re: Mariner Clanking noise...Pls Help...

Something to look at is the flex plate on the flywheel. When these things go bad/break/crack etc they sound just like a blown engine.

Just take the lid off and hit the flywheel with a hammer (easy). You'll know immediately... you may even be able to look and see the crack but there are no guarantees except that hammer test. If broken make sure you make exact witness marks on the outside ring and the inside ring before you change it out. Failure to do so will screw up your timing big time. One bolt hole off and you may have a REAL blown motor to deal with.

Im new at this...What lid I have to take off and what does the flywheel look like? And does it make the noise ONLY when on gear...or in neutral also?

 

[j_martin]

Re: Mariner Clanking noise...Pls Help...

Im new at this...What lid I have to take off and what does the flywheel look like? And does it make the noise ONLY when on gear...or in neutral also?

Yer in over your head. Take it to a mechanic.

my 02
John