Michael211_2000
New Member
Since everybody seems to be getting their Doo's out and ready for the holiday weekend, I'd like to say something about hydrolocking your engines... don't do it!
If you're running your PWC on the trailer hooked to a water hose, the procedure is: Start engine, turn on water... turn off water, Stop engine! I find it's best to put an on/off valve on the end of the waterhose so you can control the water flow right there at the stern of the PWC rather than running to a faucet valve.
Failure to do this in the correct order can hydrolock your engine, and that can cause major internal damage! If the engine is not running, yet you're flowing water in, it will very quickly fill up the exhaust manifold (1 of the places that water hose water is being sent to!) and back-flood the engine thru the exhaust valves. This is bad, very very bad! :banghead:
If you hydrolock your engine, it will suddenly die and will not turn over again when you try to restart it... or, if it was already dead and you try to start it it will not turn over by the starter. You have water in at least 1 piston, preventing that piston from reaching the top of the cylinder. If you hydrolock the engine while it's not running, it's bad but not too expensive... if you hydrolock the engine WHILE it is running, it's bad AND very expensive!
If you hydrolock the engine while it isn't running, either by flowing water in thru a waterhose or sinking the hull, then you will not be able to start the engine it will be locked. If it's sunk, get it un-sunk. Then pull the spark plugs out and try to start the engine... it should blow water out the spark plug holes. Continue cranking till no more water comes out the holes! Then put the plugs back in, suck all the engine oil out and change your oil (water in a cylinder will seep down thru the piston rings starting immediately and into the crankcase getting into your oil... you have to change the oil and filter after you hydrolock a cylinder!). Once you've blown all the water out the spark plug holes and changed your oil and filter, now you should be able to start the engine normally without harm. The faster you can get this accomplished the better... water (especially salt water!) corrodes the metal parts inside the engine so don't let it wait till tomorrow!
If however you hydrolock the engine while it is RUNNING, you have most likely bent the connecting rod on the piston of the cylinder which locked. There is no signficant clearance in these engines between the bottom of the piston and the crank shaft counterweight when the piston goes to dead bottom of it's stroke. Once the connecting rod is bent the piston WILL hit the crankshaft counterweight with the engine running. It'll make aweful noises! The engine will have to be removed from the hull, the head removed, the crankcase split open (there really isn't an oil pan as in an automotive engine, the bottom half of the engine actually holds the crankshaft in place), and the damaged piston connecting rod found and replaced. This costs between $4K and $5K at a professional shop! Yeah, YIKES!
If you find while boating that your hull has or is filling up with water, and you don't have an electric bilge pump to pump the water out, be very wary of starting the engine... if you start it and it ingests water it WILL hydrolock and be damaged! Even if the water in the hull doesn't seem very deep, if you start the engine and turn to the right the water will all go to the right side of the hull where your air intake tube is (on most models I know of) and from there it will go immediately into the carb and into the pistons... this ain't cool!
If you're at anchor or tied up to a dock and you find your PWC is filling with water, try to get it back onto a trailer (if you're close enough to the ramp) or in a lift or push it up on a beach by hand as far as you can... then get the water out. It's alot easier and cheaper to get water out of an engine that was mostly submerged than it is to fix a bent connecting rod I assure you!
Lastly, if you have to be towed by another boat for any reason remember to tow VERY slowly (less than 5mph), or pinch close the water line that feeds water to the exhaust system before towing! If you tow very fast and that water line is not pinched closed it will force enough water pressure into the jetpump to start water flowing into the exhaust system, and it's the same as sitting on a trailer with the engine stopped and flowing water in thru a waterhose... you will fill the engine up with water! Consult your manual on which water line needs to be pinched shut before fast towing, there's usually a colored band (red or blue most often I've read) around that water line, or tow VERY VERY slowly. Make certain anybody who is using your PWC knows of these issues also!!!
And of course be careful when running on a trailer (or lift) using a waterhose... again it's engine on, water on, water off, engine off.... in that order! Also limit the amount of time you run the engine out of the water, as the jetpump water seal heats up when it's run dry (it get's no water from the water hose feed!).
Regards, have a great holiday weekend, and be safe and take lotsa pics!
- Michael
If you're running your PWC on the trailer hooked to a water hose, the procedure is: Start engine, turn on water... turn off water, Stop engine! I find it's best to put an on/off valve on the end of the waterhose so you can control the water flow right there at the stern of the PWC rather than running to a faucet valve.
Failure to do this in the correct order can hydrolock your engine, and that can cause major internal damage! If the engine is not running, yet you're flowing water in, it will very quickly fill up the exhaust manifold (1 of the places that water hose water is being sent to!) and back-flood the engine thru the exhaust valves. This is bad, very very bad! :banghead:
If you hydrolock your engine, it will suddenly die and will not turn over again when you try to restart it... or, if it was already dead and you try to start it it will not turn over by the starter. You have water in at least 1 piston, preventing that piston from reaching the top of the cylinder. If you hydrolock the engine while it's not running, it's bad but not too expensive... if you hydrolock the engine WHILE it is running, it's bad AND very expensive!
If you hydrolock the engine while it isn't running, either by flowing water in thru a waterhose or sinking the hull, then you will not be able to start the engine it will be locked. If it's sunk, get it un-sunk. Then pull the spark plugs out and try to start the engine... it should blow water out the spark plug holes. Continue cranking till no more water comes out the holes! Then put the plugs back in, suck all the engine oil out and change your oil (water in a cylinder will seep down thru the piston rings starting immediately and into the crankcase getting into your oil... you have to change the oil and filter after you hydrolock a cylinder!). Once you've blown all the water out the spark plug holes and changed your oil and filter, now you should be able to start the engine normally without harm. The faster you can get this accomplished the better... water (especially salt water!) corrodes the metal parts inside the engine so don't let it wait till tomorrow!
If however you hydrolock the engine while it is RUNNING, you have most likely bent the connecting rod on the piston of the cylinder which locked. There is no signficant clearance in these engines between the bottom of the piston and the crank shaft counterweight when the piston goes to dead bottom of it's stroke. Once the connecting rod is bent the piston WILL hit the crankshaft counterweight with the engine running. It'll make aweful noises! The engine will have to be removed from the hull, the head removed, the crankcase split open (there really isn't an oil pan as in an automotive engine, the bottom half of the engine actually holds the crankshaft in place), and the damaged piston connecting rod found and replaced. This costs between $4K and $5K at a professional shop! Yeah, YIKES!
If you find while boating that your hull has or is filling up with water, and you don't have an electric bilge pump to pump the water out, be very wary of starting the engine... if you start it and it ingests water it WILL hydrolock and be damaged! Even if the water in the hull doesn't seem very deep, if you start the engine and turn to the right the water will all go to the right side of the hull where your air intake tube is (on most models I know of) and from there it will go immediately into the carb and into the pistons... this ain't cool!
If you're at anchor or tied up to a dock and you find your PWC is filling with water, try to get it back onto a trailer (if you're close enough to the ramp) or in a lift or push it up on a beach by hand as far as you can... then get the water out. It's alot easier and cheaper to get water out of an engine that was mostly submerged than it is to fix a bent connecting rod I assure you!
Lastly, if you have to be towed by another boat for any reason remember to tow VERY slowly (less than 5mph), or pinch close the water line that feeds water to the exhaust system before towing! If you tow very fast and that water line is not pinched closed it will force enough water pressure into the jetpump to start water flowing into the exhaust system, and it's the same as sitting on a trailer with the engine stopped and flowing water in thru a waterhose... you will fill the engine up with water! Consult your manual on which water line needs to be pinched shut before fast towing, there's usually a colored band (red or blue most often I've read) around that water line, or tow VERY VERY slowly. Make certain anybody who is using your PWC knows of these issues also!!!
And of course be careful when running on a trailer (or lift) using a waterhose... again it's engine on, water on, water off, engine off.... in that order! Also limit the amount of time you run the engine out of the water, as the jetpump water seal heats up when it's run dry (it get's no water from the water hose feed!).
Regards, have a great holiday weekend, and be safe and take lotsa pics!
- Michael
