454 has ticking noise
 

Started up the boat today and my starboard motor has a ticking noise along with the starboard bank running rich. It's probably gonna go to the mechanic soon, but anybody care to speculate what my problem is? Engine is a gen 6 330 mercruiser. Seems to idle a little rough as well. Oil is clean and has no water in it.
Thanks for any help guys

exhaust leak perhaps

i dont like to speculate but i think it is time for a compression test,how many hours do the engines have?

Mike, they have just over 100 hours on full rebuilds

Does the "ticking" sound like its in the valve covers ?? Possible lifter lash or cam issue maybe ??

I does to me, but I can't be sure. Makes a double tick noise, stumbles a little when you give it throttle, but cleans up as throttle increases. Starboard side exhaust tip had soot all around it on the transom, other 3 tips were clean.

Flat tappet cam?

First thing, do a compression check and isolate the cylinder.

Could be a number of things; broken rocker arm, broken valve spring, stuck valve, bent pushrod (along with one of the other problems), collapsed lifter. Again , compression test is gonna be the first thing to do.

gen6 all come with hyd roller cams,i doubt the person who did the rebuilds changed to flat tappit but stranger things do happen.

Nope, it's a roller