Strange tapping noise behind engine- Mercury 350Alpha 1 drive

Good evening,

I have a 1985 Mark Twain 190BR. It has Mercury 5.7 260HP and a SEI Alpha 1 Gen 1 drive. I am chasing down a tapping noise behind the motor. The noise sounds like it's near the flywheel. The noise is the same at idle or under power. It's a tap I can hear over the motor, occurs every 5-10 seconds.

I took the drive off to replace the u joints, bellows and gimble bearing, it still does it with no drive on so I know it's not the drive. Could it be the ring gear on the fly wheel? If so, do I need to pull the motor to inspect and change

Thanks for your time.

I'm thinking it my be that spring loaded plate between the flywheel and driveshaft.

Jeff

Most likely the exhaust flapper has lost its rubber outer shell and the metal is hitting the exhaust tube.


Item 6

http://www.marineengine.com/parts/m...haust-system-use-with-15-degree-exhaust-elbow

fastjeff said:

I'm thinking it my be that spring loaded plate between the flywheel and driveshaft.

Jeff

Click to expand...

Thanks for the response. Are you referring to the engine coupler? I don't recall anything else back there besides the flywheel, ring gear and coupler. If I'm wrong, please educate me.

kghost said:

Most likely the exhaust flapper has lost its rubber outer shell and the metal is hitting the exhaust tube.


Item 6

http://www.marineengine.com/parts/m...haust-system-use-with-15-degree-exhaust-elbow

Click to expand...

Thanks for the reply. I'll pull the elbow off and look.