Engine stalls when cover replaced on T9.9exrw 1998
Posted: Thu Sep 05, 2013 4:05 pm
Problem;
Engine rpm reduces slowly to a stall when the engine cover is installed.
When I put the engine cover back on and seal it locked the engine rpm reduces from a 1000 rpm idle to about 400 rpm, sometimes staling. This is an immediate reaction of less than 30 seconds.
What I have tried so far.
The Carburetor has been totally disassembled, all parts ultrasonically cleaned and a Yamaha rebuild kit installed. The electrothermal choke has been tested and found functioning normally.
One outboard mechanic’s first comment was that I have a hole in the gasket that is in between the power head and the exhaust and that the carbon monoxide is starving the motor.
I have Referenced 3 shop manuals to find out more about the exhaust system and how it works. The only reference that I can find is referring to
the “Exhaust / Water Jacket Cover” that is on the port side of the power head. According to the manuals there is water cooling this cove. I have not seen any sign of water leakage during running.
Request
Can any one tell me exactly from where carbon monoxide could enter the engine cavity that is enclosed by the engine cover.
Has anyone experienced this problem or would anyone be able to direct me to illustrated diagrams of the parts that make up the over all exhaust system.
If there are already posts on this subject please list the names so I can refer to them.
Thanks so much
Magic Time
Engine rpm reduces slowly to a stall when the engine cover is installed.
When I put the engine cover back on and seal it locked the engine rpm reduces from a 1000 rpm idle to about 400 rpm, sometimes staling. This is an immediate reaction of less than 30 seconds.
What I have tried so far.
The Carburetor has been totally disassembled, all parts ultrasonically cleaned and a Yamaha rebuild kit installed. The electrothermal choke has been tested and found functioning normally.
One outboard mechanic’s first comment was that I have a hole in the gasket that is in between the power head and the exhaust and that the carbon monoxide is starving the motor.
I have Referenced 3 shop manuals to find out more about the exhaust system and how it works. The only reference that I can find is referring to
the “Exhaust / Water Jacket Cover” that is on the port side of the power head. According to the manuals there is water cooling this cove. I have not seen any sign of water leakage during running.
Request
Can any one tell me exactly from where carbon monoxide could enter the engine cavity that is enclosed by the engine cover.
Has anyone experienced this problem or would anyone be able to direct me to illustrated diagrams of the parts that make up the over all exhaust system.
If there are already posts on this subject please list the names so I can refer to them.
Thanks so much
Magic Time