Loss of compression after prop strike

webb

Recruit
Joined
Aug 7, 2007
Messages
5
Hit a sandbar under full power with a 1977 75HP Evinrude--there was sudden engine stopage. On the way back to the dock, even under full throttle, the engine seemed to be producing much less than normal power. I was hoping for a spun prop but the marine shop said there was no compression in one cylinder and the prop was not spun. Cart this engine off to the landfill or...?
 

angus63

Captain
Joined
May 20, 2002
Messages
3,726
Re: Loss of compression after prop strike

Have you pulled the head for a peak?
 

webb

Recruit
Joined
Aug 7, 2007
Messages
5
Re: Loss of compression after prop strike

Not being too mechanical, I did not pull the heads--should I have the marine shop do so or is that a major undertaking in one of these three cylinder engines. apparently it is the middle cylinder that has no compression. So, lets say I have the head pulled-off, what would I see that would indicate taking engine to the land-fill verses going forward with some sort of repair. The marine shop suggested it would cost + - $1000.00 to repair the engine and that it was not worth fixing.
 

reload

Petty Officer 1st Class
Joined
Jun 29, 2004
Messages
368
Re: Loss of compression after prop strike

Pulling the head is not big deal. Get a manual and lets get started. After the head is pulled you can see the top of the piston and the condition of the cylinder walls. Before even pulling the head, try pulling the plugs and see if the piston is moving in that hole. If you have zero compression you may be in for a trip to the landfil. Did he say there was no compression or low compression?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Loss of compression after prop strike

Damage to a cylinder certainly would cause loss of power. However, it is hard to imagine it being related to hitting a sandbar. Unless it got all clogged up with sand and overheated? Severe overheating can cause severe damage.
 
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