Hey guys, not so quick ? for ya...
I have a mid/late 70's 21ft Islander with a 140 mercruiser I/O, and a few months ago I was out on puget sound returning from a successful day crabbing...Coming back in at about 3500 rpm there was a loud bang that came from the stern,followed by a redlined engine and a loss of propulsion plus my friend getting thrown off the dog house up to the the cabin bulkhead..lol
After verifying that the engine didn't have any holes in the side, I got back to the beach and got my boat loaded...After talking to the local marina mech I figured that it was blown drive coupling or a spun prop...
FFW to last night and after getting the drive pulled..
Looking thru the gimbal bearing, I did not see any damage to the drive coupling, no chunks of rubber anywhere and no burnt rubber smell.
The bonded rubber on the prop is good
I put the drive in fwd and spun the input shaft and there was no prop shaft movement and no noise or resistance aside from well lubed bearings.
I stuffed the prop on and spun it in both fwd and reverse and heard the water pump moving but the input shaft did not turn at all.
I'm kinda cringing because I have a feeling that one of the 3 shafts in the drive has failed...I replaced the raw water pump impeller about a year ago and serviced the drive with marine grease and oil, but I have yet to drain the oil and separate the upper and lower.....:facepalm:
Does anyone care to speculate on what my worst case scenario might be and what the cost would be for repair parts?
I have a mid/late 70's 21ft Islander with a 140 mercruiser I/O, and a few months ago I was out on puget sound returning from a successful day crabbing...Coming back in at about 3500 rpm there was a loud bang that came from the stern,followed by a redlined engine and a loss of propulsion plus my friend getting thrown off the dog house up to the the cabin bulkhead..lol
After verifying that the engine didn't have any holes in the side, I got back to the beach and got my boat loaded...After talking to the local marina mech I figured that it was blown drive coupling or a spun prop...
FFW to last night and after getting the drive pulled..
Looking thru the gimbal bearing, I did not see any damage to the drive coupling, no chunks of rubber anywhere and no burnt rubber smell.
The bonded rubber on the prop is good
I put the drive in fwd and spun the input shaft and there was no prop shaft movement and no noise or resistance aside from well lubed bearings.
I stuffed the prop on and spun it in both fwd and reverse and heard the water pump moving but the input shaft did not turn at all.
I'm kinda cringing because I have a feeling that one of the 3 shafts in the drive has failed...I replaced the raw water pump impeller about a year ago and serviced the drive with marine grease and oil, but I have yet to drain the oil and separate the upper and lower.....:facepalm:
Does anyone care to speculate on what my worst case scenario might be and what the cost would be for repair parts?
