wakeup 19
Member
- Nov 14, 2008
- 678
- Boat Info
- 1992 300 Sundancer, Quicksilver ding w/ 6hp merc 4 stroke, anchorlift windlass, extended swim platfo
- Engines
- t/ 350 merc's (carburated) alpha drives gen II
About a month ago on my way to Aquapalooza I throttled up 92, 350 i/o 300 da and heard rapping.
went back to dock took Valve cover off and pressed in stud was lifting up and rocker came loose. fixed temporarily for the day.
Took head off and found bent exhaust valve on #5 cylinder. Replaced with re-built head as mechanic saw some wear and thought that was best long term course of action.
put the engine back together tuned and timed it up. went out with friend for shakedown and ran great for 1 mile then hit no wake zone for 20 min and gassed back up again to hear hard knocking and no power.
limped back to dock. at low rpm you wouldn't suspect a problem ran quiet.
took other Valve cover off to find bent and jammed pushrod on #8 other side of engine. it was jammed down still on rocker but off valve. (exhaust valve again) this caused lifter to collapse as well.
I put brand new manifolds and risers on at the beginning of the season for preventative maintenance changed oil after new head, no signs of water intrusion in oil.
pulling what little hair I have left to figure out what the issue causing this is.
I have $800 into port side and going to pull other head this weekend.
compression was good on port before and after head replacement.
spoke to many mechanics and know one can seem to tell me why this is happening?
help appreciated.
went back to dock took Valve cover off and pressed in stud was lifting up and rocker came loose. fixed temporarily for the day.
Took head off and found bent exhaust valve on #5 cylinder. Replaced with re-built head as mechanic saw some wear and thought that was best long term course of action.
put the engine back together tuned and timed it up. went out with friend for shakedown and ran great for 1 mile then hit no wake zone for 20 min and gassed back up again to hear hard knocking and no power.
limped back to dock. at low rpm you wouldn't suspect a problem ran quiet.
took other Valve cover off to find bent and jammed pushrod on #8 other side of engine. it was jammed down still on rocker but off valve. (exhaust valve again) this caused lifter to collapse as well.
I put brand new manifolds and risers on at the beginning of the season for preventative maintenance changed oil after new head, no signs of water intrusion in oil.
pulling what little hair I have left to figure out what the issue causing this is.
I have $800 into port side and going to pull other head this weekend.
compression was good on port before and after head replacement.
spoke to many mechanics and know one can seem to tell me why this is happening?
help appreciated.