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MERCURY - 115 H.P. 1987 Chatter below water pump

D

doskocilj

New member
I have replaced the water pump, chatter is worse that before I changed the pump. Water pump needed to be done, however the chatter is not the reason I changed the pump. I thought,? Chatter is normal of a old motor. Sounds in-between a bad bearing and gears clacking.??? What say the Pro's??
 
Describe in more detail what the chatter sounds like and when it occurs. Sometimes it's normal and caused by the prop rattling the shifter clutch dog in the lower unit. Sometimes it's something else.

Mark
 
Ok, Well I did a text book Trouble shoot. I took the throttle and the shifter loose, started the motor. I then manually from the motor worked the shifter lever. I put it to dead center with no change to clacking. I took the lower end back off, 5 minutes. Started the motor back up the chattering was still there. Using my large screw driver as a stethoscope it appears the be the Bearing close to what the assembly shows to be the reeds or part of the reeds. MAINS Are shot? I guess this requires cracking the case open to replace? Rollers, Balls or Needle?
 
Ok if you think the mains are shot, run 16:1 oil. That's 1 1/2 quarts of oil per 6 gallons or 8 oz oil per gallon. If the problem is in the fuel supply line this ought to make a change in the noise. Yes you will smoke like xxxx but a short test like this is a lot cheaper than ripping everything apart if it's not necessary. When you are finished, go back to your regular mix and throw a can of Sea Foam in the tank. It will/should clean up any carbon you loaded up.

Mechanical noises are hard to pinpoint. BTDT Sometimes it's a best guess.

Stay in touch.

Mark

Mark
 
Mark, I am reading what you wrote, however is this going to fix the bad bearing or just lube it up to a point of no noise? Seems the bearing chatter would go away and then when I switch back to 50:1 then the bearing chatter will start again?

Thank you, Jdosk
 
Gotchya, all I have is the power head running. The foot and shaft are of the motor. It defiantly has the most noise at the bottom main. Can that bearing be removed without spitting the case?
 
Yes and no. The housing pulls off with a puller, but the bearing remains of the crank (and requires heat to get off). Also, there's not much space to get the jaws of a puller on the bearing.

You might have to split the cases after all, which is not that hard. Just don't--for heavens sake--pull the rotating assembly out! Putting those 6 pistons in is a bear.

Jeff
 
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I posted this a while ago. I am going to put in 30 to one mix and see if this chills the noise. I was running 50 to one on this old feller and I guess it was thin perhaps. ? No smoke no Lube right?

Oh ,, Dang post title is wrong I did not have the power head off when I discovered the noise at the bottom of the engine.:)
 
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