Bob B. question for you

[Gilbert Scales2]

I have a 2006 2 stroke Mercury 90 horse motor. I have a squeal, sound that seems to be getting worst. It only happens after it is warmed up, run hard for awhile, and when I come to idle. It idles good, and I have 126 psi in the 3 cylinders. Today I believe I heard it when I was getting on plane. Peaks out at 5600 rpm's, always used Merc oil. I checked with one mechanic, and he said he would have to check everything including the lower unit. Another said this has happened before, and it is the drive bearing. He said nothing would be hurt. I took my lower unit off, and greased the shaft, didn't help. Any advise would be appreciated. Don't want to cause more problems. I asked my mechanic if I could pay him to take a ride with me, he said the only thing that would do is let him know there is a noise. It wouldn't help him dianose the problem. Please set me on the right track.

Bubby:unsure:

 

[Bob Bourget2]

If it were the driveshaft bearing, the squeal would be followed by an abrupt seizure. There really isn't any "grace period" with those. What I would place my money on is the upper end crank / cap bearing, right below the flywheel. The primary lube is from the bleed line that runs from the bottom bearing to the top. Before you get "over-diagnosed", have your trusty Tech get out his stethescope {if he doesn't have one, he prob isn't the guy you're looking for}, and listen to the problem area WHEN it is occurring. HINT....if he doesn't have one, a long screwdriver usually will suffice.......although not nearly as accurate.....check here first. BE CAREFUL SINCE IT IS RIGHT BELOW THE FLYWHEEL. Another hint....it is VERY pronounced IN THE WATER, less so in the shop. Let us know the outcome.

 

[Gilbert Scales2]

Thanks Bob!! If it is the upper bearing, is it a big job to replace?



Bubby

 

[Bob Bourget2]

Well...yes. Sorry. The powerhead has to be removed, the carb / intake removed, electricals and the crank half separated. New bearing and seal, re-assemble. Approx time 7 hours plus parts.