rattle after some engine work

[ivanho]

Hi folks,

We had some work done on our 2001 226 with a Mercruiser 6.2. It sat at the shop for a few weeks due to work schedule.

Here's the work the shop performed:

New manifolds (one had corrosion), spark plugs/tune up, impeller, took off lower unit and grease/align, changed fluids, belt.

I brought it home today.

I hooked up the muffs and started it, and let it run for a couple minutes. It idled fine. When I increased RPM's a bit, there was a noticeable rattle. It was not hard to hear. I couldn't pinpoint it. The rattle did not follow the RPM's. When I dropped it back to idle, the rattle went away.

I'm not a mechanic, but have worked a bit on various cars over my life, so not a complete novice either. I shut it down and did some googling for a couple hours.

The trim was up. I've previously had it on the muffs, but don't remember if the trim was up.

I came back out and put the trim down and started it again, and went through the same sequence. No rattle this time. So I at least feel a bit better.

If anyone has any thoughts or can point me to further steps to diagnose, let me know.

I don't think this would be normal, but again, I don't remember if I've always had the trim down when running it with the muffs.

Thanks...

[rabiddawg]

Do you have captains call? I have a flapper valve that rattles. I can hold a bit it of pressure on it and it stops.

I’ve tried adjusting it’s travel to no avail. Fwiw, it’s a aftermarket replacement solenoid.

[bruceb58]

You had the drive up when you started it? Probably the U-joints making noise which is why you never start the engine with it tilted up.

[dustinm]

I always run the trim so the prop shaft is parallel to the ground when Im on muffs.

[ivanho]

I had the drive up the first time with the muffs. This is our second year boating, so I'm a little green.

We had it out on the lake today and it ran flawless, so I'll add this to the lesson's learned column.

Thanks for the feedback...

[dustinm]

I had the drive up the first time with the muffs. This is our second year boating, so I'm a little green.

We had it out on the lake today and it ran flawless, so I'll add this to the lesson's learned column.

Thanks for the feedback...

Good to hear you don't have any problems . We were all new at one point and I'm not far behind or I guess ahead of you lol. Have any pics of this boat, I think we all like looking at any Cobalt

[ivanho]

The third kid is on the boat reading...

20200830_105237.jpg

[dustinm]

Nice

[Lockey14s]

yes the rattle was your U joints screaming for help lol. but its a rookie mistake, live and learn. you dont have to have the drive ALL the way down, but try to get it to a point of normal operation (like it was in the water).

when the engine is running, even in neutral, the outdrive is spinning. its only the lower prop shaft that engages when you put it in gear.