Another engine problem,(weird noise) need help, Hank maybe

[big easy]

Ok guys,some of you know that I recently finished restoring my project boat.

Well the engine I installed (a 350 Mercruiser with a 4bbl carb and Alpha drive),is making a strange noise.

This engine runs perfectly,has great compression in all cylinders,and has only 200 hours on it.

The noise is hard to explain,but seems to be coming from the rear of the engine closer to the inner transom plate,and lower,around where the coupler is.

Please bear with me and try to use your imagination.It sounds kind of like a metallic clicking or clacking like sound.The engine will be running nicely,but there is this kind of constant,but also sporadic clickity,clackity sound.

When it is at idle, the noise is most evident,and it doesn't increase when I rev it up to higher rpms.

I thought maybe it was from the Flappers that keep water from entering the manifolds,but they were in perfect condition when I installed the engine a few months ago.They still had the rubber coating on them,and it was good on both Flappers,and the sound is much lower than that.

I sea trialed it this past weekend,and had no problems with it,Oil pressure is at 40lbs,water temp never climbs above 150,The drive shifts good.,and the boat performed great.

Also before I ever ran the engine and drive,I brought the boat to a boat dealer I trust,and had them align the engine and drive.

I sure hope couplers don't make that noise.

I should mention that the starter sometimes acts as though the battery is dead,it will go uh uh uh,then it turns over great, and the engine fires up immediately.I guess I should have changed the starter when I had the engine out "DUHHHH"

Anyway if anyone can help me here it would be appreciated.Thanks guys

[L&M]

If your sure the alignment is ok as well as the exhaust flaps. I would pull the starter and check to make sure it isn't hanging up and the drive isn't touching the flywheel after it starts. Also check that the lower flywheel cover is tight and not bent so that is touching the flywheel. ( the sheet metal cover that bolts to the bell housing underneath )

[Erbyjoe]

John could it be electrical?like something shorting out to ground or something like that?

[ray koziatek]

are you missing your pet cat??If it goes click,click,click,moew dont worry for a week it should be coughing up hair balls shortly.

[Diversion]

John, is the noise still there when you advance the throttle under load, past 1000 RPMs? If so, it is most likely the exhause flappers.

[slamin salmon]

i had the same noise with the same engine but only at a idle. it ended up being a clutch plate but this did not change the performance. when you raise the rpm, the noise disappeared. hope this helps

[sybil]

I've had the same sound as you describe for over 15 years on the same setup as you. I have to agree that it is the flappers. On another note my starter also does the same thing as you say, and again its been that way for years.