1988 Force 50HP Noise?

Hi;
I have a 1988 Force 50HP (507F8C). Took it out last week and noticed it takes longer to get onto plane (no trim/tilt). Also, top speed seems a tad slower than normal. Starts fine and except for slower top speed seems to run fine. What I DID notice is a loud shreiking noise as motor reached higher RPM (in gear). At idle and slow speeds there is no shreik noise. As engine gets up to about 2/3 throttle I start to hear it. At full throttle it is very loud. It sounds like when you use an air compressor blow-off nozzle and blow it thru a short piece of pipe. As I throttle back, the noise decreases and dies off at about 1/2 throttle. Not sure if deceased top end and this noise are related or not.
Anyone have any ideas please?
Thanx

Re: 1988 Force 50HP Noise?

Someone posted here before that shriek noise is roller bearings gone bad.... crank or rod bearings

Re: 1988 Force 50HP Noise?

Bob may be on to something, under the flywheel in the top of the case is the upper crank bearing. It is a roller style with ball bearings. Mine went bad last season, but had no screeching or anything. It fell apart dropping the ball bearings into the case. Luckily all of the bearings were ejected out the exhaust. This is an easy check, just pull the flywheel, then the stator plate, then you can see it clearly. If this bearing is bad, you must split the case and remove the crank, then have a new bearing pressed on by a shop. It's not too bad to do, if I could do it anyone can The only time I have ever heard shrieking from my motor is when I sheared the flywheel key. If it were me, I would check all my lubrication. Lower unit oil, my premix fuel, etc. Then inspect the engine when it is running in the barrel or on muffs, to see if there is something visually wrong. Maybe you will get lucky and it will be just something rubbing the cowel at WOT? In other words, check the simple stuff first, eliminate possibilities, then proceed with the harder dissection stuff. Hope that helps