Turns out it was the Water pump. Thank you all for your suggestions.
Ran it without the belt for a very short time to isolate the accessories.
Once belt was off the noise did not happen any more.
So took off water pump to see what was inside and making the noise.
Check out the video and see...
I will be doing a bit more checking with stethoscope and camera prior to any major removal of hardware. it sounds like it is coming from the left side of the engine. near the pushrod/lifter panel that can easily be removed. Do you know if the lifters are hydraulic lifters? I would think they...
The shift cable is set correctly as well. Initially it was set at 5.5 with a pinned barrel nut. no adjustment could be made. So installed new stainless cable sleeve with adjustable barrel nut. Now the cable is set at 6.00" on the money. Forward gear locks in place and reverse locks in...
Thank you for your suggestion about removing the drive. The sound could be transferring into the engine possibly. I will be scoping through the spark plug holes tonight just to take a peak.
I can run above idle speed and the noise does not always occur.
This is a tricky sound do to its...
Thank you for your input. I would never do that. I am not new to boating just this is a new boat to me. I do like your suggestion in taking off the lower unit and running then to see if it could be the problem.
This is a new to me boat. The part that stumps me is that I have it running so smooth. Then all of a sudden the strange noises start happening then they disappear just as fast as they started. I did hear a video last night that sounded very similar and it was the timing chain someone had...
Thank you for your prompt reply,
I did go to mercury website and entered my serial number, no luck on the manual for some reason.
I am in the midst of a rattle sound that does not change with the RPM's. It is intermittent and generally starts at 2500 rpm. Then will stay clattering...
Is there a good reference manual or source that specifies the many specs for the 3.0 4 cyl.
I am in the midst of getting initially a non running engine running and things are going pretty well so far. I am looking for the correct idle speed for this engine currently. Also can someone verify...
