Crankcase vapor explosion!
05-29-2008, 08:43 AM
#21
Gold Member
Gold Member
Join Date: May 2002
Location: DFW
Posts: 1,127
Likes: 0
Received 0 Likes
on
0 Posts
Opinion seems to lean away from electrical and towards mechanical.
However,the port engine had run satisfactorily, 6 hours earlier, re-started and appeared to be idling normal. Simultaneous with starting the center engine (creating current draw) the then idling port engine experienced an explosion.
There is nothing to indicate a burned piston or other mechanical failure....Though some definite volume of fuel was in the crankcase,that was mechanical.
However,the port engine had run satisfactorily, 6 hours earlier, re-started and appeared to be idling normal. Simultaneous with starting the center engine (creating current draw) the then idling port engine experienced an explosion.
There is nothing to indicate a burned piston or other mechanical failure....Though some definite volume of fuel was in the crankcase,that was mechanical.
05-29-2008, 08:54 AM
#22
Banned
Opinion seems to lean away from electrical and towards mechanical.
However,the port engine had run satisfactorily, 6 hours earlier, re-started and appeared to be idling normal. Simultaneous with starting the center engine (creating current draw) the then idling port engine experienced an explosion.
There is nothing to indicate a burned piston or other mechanical failure....Though some definite volume of fuel was in the crankcase,that was mechanical.
However,the port engine had run satisfactorily, 6 hours earlier, re-started and appeared to be idling normal. Simultaneous with starting the center engine (creating current draw) the then idling port engine experienced an explosion.
There is nothing to indicate a burned piston or other mechanical failure....Though some definite volume of fuel was in the crankcase,that was mechanical.
05-29-2008, 08:56 AM
#23
Charter Member
Merc computers don't like to run in ALL position. On my boat it will break down at about 3000 rpms if the switches are set to ALL. If he is running carbs it might not be an issue, but it is still better to run a sep battery for each engine.
VIP Member
05-29-2008, 12:20 PM
#25
Registered
Join Date: Sep 2001
Location: Houston, TX, USA
Posts: 2,287
Likes: 0
Received 0 Likes
on
0 Posts
Do a compression check or leak down. You will find the cylinder with the problem. I am betting leakdown will show one blowing into the crankcase big time.
When you were running you may have had motor in detonation. The piston got fractured but did not let go until you had the engine running again.
When you were running you may have had motor in detonation. The piston got fractured but did not let go until you had the engine running again.
05-30-2008, 07:12 AM
#28
Banned
05-30-2008, 07:28 AM
#29
Registered
Platinum Member
Put the valve covers back on and see if it will blow the supercharger off the top of the engine next time. 
Just kidding. Hope you find the problem. I am out of suggestions.
My theory is that if you fix the fuel problem, the rest won't matter.
Just kidding. Hope you find the problem. I am out of suggestions.
My theory is that if you fix the fuel problem, the rest won't matter.
