Sneakers
Just sneakin' around....
Kom mentioned a jet ski kill cord in another thread, and just wanted to share this. My brother has a 1 year old Cobalt boat with a Volvo engine/outdrive. He texted me yesterday that he was getting a new engine installed. Apparently, the marina summer-ized the boat, and hydrolocked the engine in the process. Hydrolock is when you get more than just a mist of water in the cylinder. Since water is non-compressible, serious damage can happen; bent rods, cracked cases, etc. Bro didn't detail any damage extent, just that it a known issue on this Volvo motor series and the factory is covering 100% of the parts and repair.
I did some online searches, and found it's a lot more common that I realized. Very common in jet skis that flip, and in larger boats that haven't been designed properly, like no siphon-preventer on exhausts below the water line, which allows water right back in thru the exhaust.
But two reasons for hydrolock really made me think.... one is the kill cord. Apparently, if an engine is at high RPM and the kill cord is yanked causing a fast hard shutdown, the engine can suck water in and hydrolock. At that RPM, severe damage is expected. The other is the timing of the motor. If timing isn't correct, the engine could actually turn in reverse for a revolution or two when shut off. This can suck water right into the exhaust port and hyrdolock the motor.
So, just passing this on. I've been around boats and boat motors forever, but never was first hand witness to a hydrolock situation. I'm sure tho that our resident boat engine repair folks have.
I did some online searches, and found it's a lot more common that I realized. Very common in jet skis that flip, and in larger boats that haven't been designed properly, like no siphon-preventer on exhausts below the water line, which allows water right back in thru the exhaust.
But two reasons for hydrolock really made me think.... one is the kill cord. Apparently, if an engine is at high RPM and the kill cord is yanked causing a fast hard shutdown, the engine can suck water in and hydrolock. At that RPM, severe damage is expected. The other is the timing of the motor. If timing isn't correct, the engine could actually turn in reverse for a revolution or two when shut off. This can suck water right into the exhaust port and hyrdolock the motor.
So, just passing this on. I've been around boats and boat motors forever, but never was first hand witness to a hydrolock situation. I'm sure tho that our resident boat engine repair folks have.
