New engine noise

brewern

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Joined
Dec 31, 1969
Messages
12
This weekend we took our new (to us) 1980 Rinkerbuilt out for the first time. (Many thanks to this forum for helping me pick it out.)
The first day and a half it ran great. But then, the engine started making a clanging noise in time and cadence with the RPM's. At about 50% or lower throttle, it doesn't make the noise. But at higher RPMs, it starts clanging. I limped back to camp and checked the oil, that was fine at about half full. I went ahead and added a half quart just to top it off. I realized I didn't have the blower on.... maybe I overheated it?
I let it sit the rest of the day, and the next day, we set off to get ice and the sound was gone! Hmmmmm.... on the way back from the marina though, it started again.
We took a couple videos in hope a mechanic might hear the noise and recognize the problem. Here's video #1, the sound, and the curious dog starts at 7 seconds:


The sound went quite 1 or 2 more times over the rest of the weekend, but most of the time it's quite audible.

Thanks in advance for any help!
Neil
 

brewern

Cadet
Joined
Dec 31, 1969
Messages
12
Re: New engine noise

Here's video #2, but the sound is so blown out I doubt it helps:

 

brewern

Cadet
Joined
Dec 31, 1969
Messages
12
Re: New engine noise

For any future readers, it turns out it's the valves. It needs a valve adjustment, and for my engine, the Mercruiser 350, aka the "Iron Duke", here's a video showing exactly how to do it:


Doesn't look too hard....
 
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