# '98 Merc 25 Squeak



## rkmurphy (Nov 2, 2008)

Decided to start a new thread as the old topic was kind of away from the current issue.

A little update...I ran the boat today at a lake and I noticed 2 things:

1) It was pissing sh*tty again and the pee stream was lava
2) It was still squeaking after a WOT run

I headed back in making sure the motor wasn't overheating, which it wasn't. When I got back to the house I took the "filters" off of the lower unit and took a hose to the pee tube on the motor. I put the hose sprayer on the "jet" setting and shot it through for a couple of minutes. I reinstalled the "filters" to the LU and hooked it up to muffs. The motor pees fine now. I ran it for at least 20 minutes, increasing the rpm's sometimes. Seems good now.

Next issue is the squeak. When I was heading in to the ramp I had my fiance steer and I listened in on the motor. It's not coming from the motor at all. In fact, it sounds like it's coming from either the exhaust housing or the lower unit. I checked the gear oil and it looked fine. Now, the question is, what could be causing a squeak from an exhaust housing or LU ONLY when coming off of WOT?


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## Brett (Jul 16, 2008)

Metal on metal, the reverse lock bar might be loose and rubbing?
Slowing down puts drag on the lower unit and pulls the motor
away from the transom, somethings loose and moves, squeak...

or maybe you trapped a mouse in there...


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## islander1225 (Jun 15, 2008)

sounds like to me it is just sounding like a good ole 2 stroke lol.


Alex


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## rkmurphy (Nov 2, 2008)

> or maybe you trapped a mouse in there...


I called Bud's to see if they were eating cheese when they pulled the lower unit. He said no . Which is really frustrating because that would have been a simple issue to solve.

Anyone else have any thoughts?


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## Un-shore (Sep 27, 2007)

Loose motor mounts?

Did you say you replaced to impeller since the squeeking started?


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## rkmurphy (Nov 2, 2008)

Yes I did replace the impeller.  How would I check for loose motor mounts?  It does seem to shake excessively at idle...

Edit: Spoke with AFA Marine today since they always seem to be the most knowledgeable...I hate pestering them with my issues all of the time, though. Anyhow, he just said to not worry about it...it may just be a sound the motor makes. "If it's gonna blow up, it's gonna blow up and there's not anything any mechanic can do about it but rip the motor apart to see what may be wrong." He said it's probably nothing, though.

Anyways...looks like you may be right, Alex. That's the second time that you've been right about my motor now. Haha.

I'd still like to know how to check the motor mounts, though.


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## Un-shore (Sep 27, 2007)

motor mounts #3 and #20 ;http://www.marinepartsplus.com/catalog/mercury/serial/25/+99917/1138-120

Look for obvious wear and eccessive play. A good test is spray a little armor all on them and see if the squeeking stops. A worn or broken mount could be hazardous to your health.


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## rkmurphy (Nov 2, 2008)

> motor mounts #3 and #20 ;http://www.marinepartsplus.com/catalog/mercury/serial/25/+99917/1138-120
> 
> Look for obvious wear and eccessive play. A good test is spray a little armor all on them and see if the squeeking stops. A worn or broken mount could be hazardous to your health.


What about WD-40? Could I test it with that or would WD-40 be bad for the mount?


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## Un-shore (Sep 27, 2007)

I think wd would be okay.


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## rkmurphy (Nov 2, 2008)

Ran the boat today and didn't squeak all day until I opened it up on the way back. The squeak is fairly loud and if I "bump" it with a little bit of throttle (just a quick on and off) while I'm idling it gets louder and even chirps a little bit (very rapidly...so I don't think it would be a sneeze). It eventually fades off.

It runs great, though, and doesn't seem to be overheating. I shot some silicone spray on the lower motor mounts and up and down the drive shaft (from the small, tiny area where it's visible), just for sh*ts and giggles.

Anyway, keep the thoughts coming.

I took the cowling off and I guess the spark plugs weren't tight enough (barely finger tight) because gas/oil was leaking out of them (not quickly or anything). I inspected the plugs and they look really good...not fowled or anything, as I compared them to that chart someone sent me on another thread (B. Lee, I think). I did notice this yellow ring around the base of the plastic part that says "Autolite".

Here's some crappy pics:




























Not sure what this is...but would like to know .

Thanks everyone for your help so far.


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## Brett (Jul 16, 2008)

The discoloration looks like cooked lubricant, WD 40 maybe?
Spark plugs are meant to be torqued in place to the proper specs.


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## rkmurphy (Nov 2, 2008)

> The discoloration looks like cooked lubricant, WD 40 maybe?
> Spark plugs are meant to be torqued in place to the proper specs.


Possibly WD-40 or whatever the mechanic had on his hands when he repaired my thermostat.

I torqued down the plug according to the repair manuals instructions.  Should be fine, now.


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## Un-shore (Sep 27, 2007)

did the chirping sound stop after you tightened the plugs?


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## rkmurphy (Nov 2, 2008)

> did the chirping sound stop after you tightened the plugs?


I'm not sure yet.  Won't be able to run it til the end of the week.  I think I'm going to SeaFoam blast it and replace the gear lube before I take it out.  Then I'll run the piss out of it.  

Update:

Just bought a can of SeaFoam and bottle Quicksilver gear lube. I also returned the Attwood fuel tank as it was just plain crap. I'm going to run by West Marine tomorrow and get a Moeller tank and tank fitting as well as some Quicksilver Power Tune. I'm going to do the whole process that whitesnooky went through on his Merc 25. Mine could probably use an inner cleansing, anyway. I figure ~$10-$12 to try to fix the issue couldn't hurt.

I also checked the compression and both cylinders are ~130psi. The top was maybe 2 psi lower but I'm guessing that means absolutely nothing.

I'm also going to replace the gear lube and screw gaskets as I'm just not satisfied with how my last job went. Again...cheap precaution.

I'll do all of this stuff Friday and as soon as I'm done Seafoaming her, I'll take her to the local lake with some fresh gas/oil/StaBil and run her like hell.

I just want to get this issue squared away...I may be a hypochondriac but I just don't have a good feeling leaving it the way it is.


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## rkmurphy (Nov 2, 2008)

> > did the chirping sound stop after you tightened the plugs?
> 
> 
> I'm not sure yet.  Won't be able to run it til the end of the week.  I think I'm going to SeaFoam blast it and replace the gear lube before I take it out.  Then I'll run the piss out of it.
> ...


I just wanted to clarify why I'm worried about it running lean at top end. I made a previous post about my first outing at CRB when I opened it up on the way back in. After I did that, it started to squeak, as usual. I went to give it some throttle and it made a pop with a puff of smoke out of the exhaust and the squeak stopped.

Now, I don't know much about this but I'm guessing that maybe the main jet is letting enough fuel mix through at cruising speeds but is maybe just a little plugged up to only affect top end where it's just not letting quite enough fuel through. That's just my uneducated theory :-?.


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## grego (Oct 17, 2007)

I have a merc 60 on my boat. Now and then it will "chirp" for a short period then stop. Its been doing it since I bought the skiff. It might just be a merc thing.
Greg


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## hardin083 (Nov 22, 2008)

I have an 03 merc 25 two smoke, and just 3 days ago i noticed a small chirp while running wot.. i came off a plane to an idle and it still had a small chirp :-? shut down to fish and when i fired it back up the problem was gone and i haven't noticed it since.. but ive only had it out one time since..
i think you cursed me being how it happened after i read this thread   or maybe i never paid enough attention , but oh well ill just keep running the dog crap out of it  ;D ;D


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## iMacattack (Dec 11, 2006)

both of my old Merc 25's had a little chirp... unless it becomes a squeal I'd run the snot out of it and wait for it to go bloom!


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## Brett (Jul 16, 2008)

I 'm thinking you're hearing the noise coming from the exhaust relief holes, located as shown circled in red in this image.
Exhaust gases passing through the small diameter holes, will make some interesting noises.
And if some exhaust crud has built up in the passage way, might make the noises you're hearing


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## iMacattack (Dec 11, 2006)

> you're hearing the noise coming from the exhaust relief holes... crud has built up in the passage way, might make the noises you're hearing


I would concur, when I have crud in my exhaust relief hole, I get some funny noises too... plus a weird oder... ;D

Sorry I couldn't resist... sorry for the [smiley=no_derail.png]

Back to topic now...


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## rkmurphy (Nov 2, 2008)

> both of my old Merc 25's had a little chirp... unless it becomes a squeal I'd run the snot out of it and wait for it to go bloom!


It is like a squeal.  Not ear piercing but very noticeable.  It went away that won time after that "pop" and it only happens after WOT runs and sometimes cruising speeds.

I hate strange issues... 

Edit:

I just got this hahahaha



> I would concur, when I have crud in my exhaust relief hole, I get some funny noises too... plus a weird oder... ;D
> 
> Sorry I couldn't resist... sorry for the [smiley=no_derail.png]
> 
> Back to topic now...


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## Brett (Jul 16, 2008)

> when I have crud in my exhaust relief hole, I get some funny noises too... plus a weird odor...


Maybe add a little more fiber in your diet?.... [smiley=flush.gif]



Speaking of weird noises....there's that sound of twisting metal again...how far off track are we now? [smiley=moon.gif]


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## rkmurphy (Nov 2, 2008)

> > both of my old Merc 25's had a little chirp... unless it becomes a squeal I'd run the snot out of it and wait for it to go bloom!
> 
> 
> It is like a squeal.  Not ear piercing but very noticeable.  It went away that won time after that "pop" and it only happens after WOT runs and sometimes cruising speeds.
> ...


Got the 6 gal Moeller topside tank and some Yamaha fittings today (almost identical to Merc...they were out of Merc). Also got some new LU screw gaskets for when I change the lube.

Hopefully this stuff and the Powertune/SeaFoam blast solves the issue...

Keep the opinions coming, though! Thanks guys!


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## Brett (Jul 16, 2008)

About that exhaust noise, check for one of these...

http://www.fakecrap.com/products/exhaust_whistle.html


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## rkmurphy (Nov 2, 2008)

> About that exhaust noise, check for one of these...
> 
> http://www.fakecrap.com/products/exhaust_whistle.html


I checked...no whistle...that would have been an easy fix, too, just like the mouse in the motor!

This is the procedure I'm going to use:



> Beautiful ......it ran really good.....what u mean it's idle rough?  it's a 2-stroke...not a 4-stroke. ...just run her bat out of hell!  that's what I did to muh mariner 25hp 2-stroke.
> 
> I haven't ran my 25 mariner for awhile so  I sprayed quicksilver powertuner in the carburator and in the powerhead gasket while spark plugs out. let the motor sit overnight while it soaked.  The next day...give a one pull..spray in the powerhead and the carburator and let it sit again overnight. repeated the same thing for the next 4 days.
> 
> ...


A couple of questions:

When putting the new fitting on the new tank, should I use a threadlock or just screw the fitting in? The fitting has metal threads and the tank has plastic threads.

When you run the SeaFoam through and spray the Powertune into the throat (correct term for the air intake?), does it clean the reeds?


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## Brett (Jul 16, 2008)

My OEM tank has a metal to plastic threaded connection, no sealant or threadlock.


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## Gramps (Nov 1, 2007)

I put some teflon tape on the fitting, keep it one or two threads from the open end.


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## rkmurphy (Nov 2, 2008)

> I put some teflon tape on the fitting, keep it one or two threads from the open end.


That's what I was thinking about doing...

I sprayed of the fuel filter and filter housing today with some Powertune and let it sit for a few hours before wiping them off (I didn't wipe off the filter). Both were pretty clean, anyway. I sprayed the first nightly dose of Powertune in the carb throat and spark plug holes today, as well. I'll give it a pull tonight and spray again. Then do the same thing tomorrow night. Then, Friday is SeaFoam blasting day.


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## Un-shore (Sep 27, 2007)

I sadly wonder if future generations will be using SeaFoam Blasting Day for just another holiday to get drunk on. :'(


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## rkmurphy (Nov 2, 2008)

Ok so today was SeaFoam blasting day. My total list of materials for this whole experience:

- 1 can SeaFoam
- 3/4 gal gas
- 1 can Quicksilver PowerTune
- New Moeller topside 6 gal gas tank
- New male and female fittings for tank
- New motor fuel fitting
- New fuel line (some new brand that can handle E85...it's blue...feels like it's good quality, though)
- 1 emptied and dried 69 cent gallon jug
- 1 keg barrel to run the motor in

Over the passed few days I've been spraying PowerTune in the combustion chambers and carb throat.

Today, I filled up the barrel with water and put the motor in. I filled the gallon jug with 3/4 gal gas and ~2.5 oz oil warmed up the motor. I measured 12oz of SeaFoam and poured it in the jug as it was still running and mixed it up good. I ran it for 15 min and let it soak for 15 min. I repeated the process 3 times. Then, I hooked up my new gas tank with 3 gal of gas, 8 oz oil, some Sta-Bil, and some Quickleen (normal dosages of both). The little brother and I went to a local lake and ran it wide open for about 40-45 min. Hole-shot was great but it seemed like the prop hesitated at first...not like it's sucking air at all. But, I was going straight from idle to WOT in one swift tiller twist.

It still squeals a little but only if I get the exhaust port under water when slowing down...or so I think. I definitely think the SeaFoam made a difference, though. Sounds and feels like it runs better.

The pee stream is extremely hot after running WOT...but I figure it's normal due to all of the stress on the motor running it wide open that long (5-10 min straight WOT).

I think the motor is as good as it's gonna get at this point. Thanks all for the help! I'll post back if any further issues present themselves...pray they won't!

I would have got some pics and videos but it was raining while we were running it. By the way...don't run a boat shirtless in the rain...it hurts.


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