seadoo@19072
Member
1994 SeaDoo GTX with a sudden shut off problem – UPDATE
Since last summer, 2016 I have been posting questions regarding the problem listed below. I want to thank those of you who have offered advice and suggestions. I have noticed that few folks who post questions and receive advice and suggestions give any follow up when their problem is solved and what action they took to resolve their issue. Below, I am giving an update on my problem. If any of you have any further advice or suggestions, it would be appreciated and if someone is browsing this thread, maybe you can pick up something from my experience.
PREVIOUSLY POSTED:
I have a 1994 Sea-Doo GTX with a sudden shut off problem. During the summer this unit began to sputter, bog down and die. I found a grey slime in the bottom of the bilge. I pulled the front storage tub and found gas leaking from the fuel filter housing unit. It had come loose and lost pressure. I cleaned the bilge and replaced it with a new fuel filter housing unit. At that time I replaced the battery. The jet-ski ran fine for a few days. I was cruising along at or near full throttle when the engine suddenly stopped like the kill switch was hit or the switch lanyard was pulled. I hit the start button and it started right up but about ½ mile later it suddenly shut off again. It ran fine at ½ throttle or no wake speed back to the launch.
I took it to my local Sea-Doo dealer for repair. They checked the compression and some other things. Ran it on the hose, said it was fine. Said that the grey Tempo fuel lines were probably deteriorating and have fouled the carburetors and that I should bring it back to get the carbs looked at.
I took it home, replaced all the fuel lines, pulled the carbs and did a total rebuild on both carbs. When I pulled the carbs I found both small oil lines on the rotary valve cover were broken. One of the internal fuel filters was completely blocked. I replaced the oil lines and made sure that the oil flowed through the new oil lines by holding the oil injection pump lever wide open while idling the engine. I replaced the spark plugs with new NGK BR8ES gapped at .020. Then I took it to the lake. There is about a mile of no wake from the launch to the main body or water. It ran at no wake speed fine. I hit the throttle and it ran like a rocket for ½ mile and suddenly shut off. I immediately hit the start switch and it acted like the battery was low and couldn’t turn it over. After a few minutes I hit the switch again and it stated right up and it ran like rocket for ½ mile then shut off. I hit the switch again and it wouldn’t turn over enough to start. I waited a few minutes, hit the switch and it started right up and ran like a rocket for ½ mile. I ran back to the launch at ½ and no wake throttle.
I have not found a definitive answer to this sudden shut down problem. One of the most popular answers for this was a bad rectifier. The test for a bad rectifier was to disconnect the RED wire from the rectifier. The battery would not charge with the red wire disconnected but if it ran without shutting down you know that rectifier was bad. I am not sure if the red wire test is a plausible way to test for a bad rectifier. Some folks say to test with a volt meter. If the voltage goes up when the engine is started, the rectifier is good, if the voltage does not go up, the rectifier is bad.
I disconnected the red wire on the rectifier, took it to the lake. It ran on full throttle for ½ mile and shut down. The problem must not be the rectifier.
I don’t think that this is a fuel problem, since it runs so well when it is running. It does not sputter or bog down as if in need of fuel. I tried hitting the stop switch as well as pulling the switch lanyard while at full throttle and the response was the exact same as when it suddenly shuts off. It always happens only at full throttle and after approx. ½ mile. It is very consistent as if a timer or heat has something to do with it.
The 1994 does not have a DESS. It has a push button held in with a cap. I am going to pull the red stop switch and examine it for a problem. I do notice the switch housing is loose and that there is an Allen screw to tighten it up with.
I have been told that the reason that the engine suddenly shuts off is because it has a “lean piston” seize. There seems to be several reasons that a piston will seize and shut the engine off suddenly: lack of oil, lean fuel mixture adjustment at carburetor, blocked cooling system causing overheat, air leak in engine or fuel system. I have heard that sometime the oil pump on these Sea-Doo’s fail at full throttle and cause the seizure.
I am thinking about premixing a couple of gallons of gas, 40:1 then running at full throttle. I would expect that I am over oiling the system with both oil injection and premix at the slower speeds but if the oil injection pump is failing at full throttle without premix but runs well at full throttle with premixed gas, would indicate that the oil injection pump is failing. Over the short haul the worst that can happen is heavy exhaust smoke, fouled spark plugs or the engine suddenly shuts off. If it shuts off, it probably is something other than the oil pump. If it continues to run well on the premix, I would either install an oil injection pump block off plate and convert to premixed gas, or remove the pump, test it with an electric drill and/or repair it.
When I remove the spark plugs I can turn the drive shaft very easily with bare hand. I have a flexible inspection camera and do not see any grooves or burns on the cylinder walls or top of the pistons. Since it is now winter and I have the time, would it be a good idea to pull the head off the engine to inspect the pistons and cylinders for any evidence of piston seizure? If I do find such evidence, how would I isolate the cause of the problem?
UPDATE:
I wanted to determine if the oil injection system was the problem. I isolated the fuel system by removing the fuel pick up line from the selector switch and running a hose into a jug with 40:1 gas. The result was the same, sudden shut off. After running out of ideas, I went back to the dealership and discussed the problem with the tech. He suggested that the CDI unit may be the problem. SO…I bought a new CDI and installed it. Same result, sudden shut off. Fortunately I was able to return the CDI to the supplier. Tired and frustrated, I took the jet ski to the dealership and ask them to try to solve the problem. I was informed that “We do not troubleshoot on SeaDoos this old”. Seems that when we cheap ol’ SOBs get work done on old units, it’s like peeling off the onion skin. They fix one problem and that uncovers another. Then the customer blames the tech for doing something wrong. Therefore I had to give a specific work order. So I said, remove the head and inspect the pistons, rings and cylinders for piston seizeure. They did, and, YIKES…Pistons were burnt, rings frozen and cylinders scored. How did this thing keep running?
The consensus was, the problem started when the oil lines to the rotary valve to mix the oil with the gas dry rotted and broke, the pistons seized for lack of oil.
I sent the jugs to Full Bore to be bored and returned with rebuild kit including pistons and rings. It took a while but it was mid-summer, their busiest time. The dealership rebuilt the top end. And, so the oil problem would not happen again, I had a block off kit installed and will mix my own gas. PROBLEM SOLVED! Not quite.
I took the SeaDoo out to the lake for its test ride. I spent quite a while putting around to break in the new pistons and rings. Then I hit the throttle and off we went….for 20 minutes, then it bogged down and shut off. (Insert bad word here).
I went back to the dealership and informed the tech, what happened. He said he had checked the carburetors when he had it tore down and they were ok for fuel mix. He mentioned that he had looked at the wear ring through the nozzle and that it looked a bit suspicious. He said he has heard of a rough hull that has been beached a lot would cause air bubbles to form and be sucked into the engine and replace some of the water for the cooling system thus causing the engine to overheat and seize. He suggested temporarily replacing the water hose with a clear hose to see if bubbles are present in the water. He also said that a bad wear ring might cause the proper amount of water that is forced into the engine to be diminished and cause the engine to overheat and seize.
It was at this point that I had an epiphany. I realized that there is a heat sender on the head and a buzzer in the handlebars. If this jet ski engine is overheating, why is the overheat buzzer not going off? I pulled the heat sensor and hung it in boiling water then checked the continuity with an ohm meter and got nothing. In case the water was not hot enough, I put the torch to it, still nothing. I checked the buzzer. It worked. The heat sensor is no longer available from SeaDoo, so I ordered a used one from Ebay.
My next project was to remove and inspect the jet pump. When I got the pump out of the jet ski, I found the wear ring to be nearly disintegrated. The play in the impeller was almost 1/2” and very little oil in the cone. I am waiting on the complete rebuild kit for the jet pump.
I think I am down to the last possibility for this problem. If someone has read this complete post and has any ideas, let me know. Thank you all for the help. I am determined to fix this thing. My grandkids are depending on it.
Since last summer, 2016 I have been posting questions regarding the problem listed below. I want to thank those of you who have offered advice and suggestions. I have noticed that few folks who post questions and receive advice and suggestions give any follow up when their problem is solved and what action they took to resolve their issue. Below, I am giving an update on my problem. If any of you have any further advice or suggestions, it would be appreciated and if someone is browsing this thread, maybe you can pick up something from my experience.
PREVIOUSLY POSTED:
I have a 1994 Sea-Doo GTX with a sudden shut off problem. During the summer this unit began to sputter, bog down and die. I found a grey slime in the bottom of the bilge. I pulled the front storage tub and found gas leaking from the fuel filter housing unit. It had come loose and lost pressure. I cleaned the bilge and replaced it with a new fuel filter housing unit. At that time I replaced the battery. The jet-ski ran fine for a few days. I was cruising along at or near full throttle when the engine suddenly stopped like the kill switch was hit or the switch lanyard was pulled. I hit the start button and it started right up but about ½ mile later it suddenly shut off again. It ran fine at ½ throttle or no wake speed back to the launch.
I took it to my local Sea-Doo dealer for repair. They checked the compression and some other things. Ran it on the hose, said it was fine. Said that the grey Tempo fuel lines were probably deteriorating and have fouled the carburetors and that I should bring it back to get the carbs looked at.
I took it home, replaced all the fuel lines, pulled the carbs and did a total rebuild on both carbs. When I pulled the carbs I found both small oil lines on the rotary valve cover were broken. One of the internal fuel filters was completely blocked. I replaced the oil lines and made sure that the oil flowed through the new oil lines by holding the oil injection pump lever wide open while idling the engine. I replaced the spark plugs with new NGK BR8ES gapped at .020. Then I took it to the lake. There is about a mile of no wake from the launch to the main body or water. It ran at no wake speed fine. I hit the throttle and it ran like a rocket for ½ mile and suddenly shut off. I immediately hit the start switch and it acted like the battery was low and couldn’t turn it over. After a few minutes I hit the switch again and it stated right up and it ran like rocket for ½ mile then shut off. I hit the switch again and it wouldn’t turn over enough to start. I waited a few minutes, hit the switch and it started right up and ran like a rocket for ½ mile. I ran back to the launch at ½ and no wake throttle.
I have not found a definitive answer to this sudden shut down problem. One of the most popular answers for this was a bad rectifier. The test for a bad rectifier was to disconnect the RED wire from the rectifier. The battery would not charge with the red wire disconnected but if it ran without shutting down you know that rectifier was bad. I am not sure if the red wire test is a plausible way to test for a bad rectifier. Some folks say to test with a volt meter. If the voltage goes up when the engine is started, the rectifier is good, if the voltage does not go up, the rectifier is bad.
I disconnected the red wire on the rectifier, took it to the lake. It ran on full throttle for ½ mile and shut down. The problem must not be the rectifier.
I don’t think that this is a fuel problem, since it runs so well when it is running. It does not sputter or bog down as if in need of fuel. I tried hitting the stop switch as well as pulling the switch lanyard while at full throttle and the response was the exact same as when it suddenly shuts off. It always happens only at full throttle and after approx. ½ mile. It is very consistent as if a timer or heat has something to do with it.
The 1994 does not have a DESS. It has a push button held in with a cap. I am going to pull the red stop switch and examine it for a problem. I do notice the switch housing is loose and that there is an Allen screw to tighten it up with.
I have been told that the reason that the engine suddenly shuts off is because it has a “lean piston” seize. There seems to be several reasons that a piston will seize and shut the engine off suddenly: lack of oil, lean fuel mixture adjustment at carburetor, blocked cooling system causing overheat, air leak in engine or fuel system. I have heard that sometime the oil pump on these Sea-Doo’s fail at full throttle and cause the seizure.
I am thinking about premixing a couple of gallons of gas, 40:1 then running at full throttle. I would expect that I am over oiling the system with both oil injection and premix at the slower speeds but if the oil injection pump is failing at full throttle without premix but runs well at full throttle with premixed gas, would indicate that the oil injection pump is failing. Over the short haul the worst that can happen is heavy exhaust smoke, fouled spark plugs or the engine suddenly shuts off. If it shuts off, it probably is something other than the oil pump. If it continues to run well on the premix, I would either install an oil injection pump block off plate and convert to premixed gas, or remove the pump, test it with an electric drill and/or repair it.
When I remove the spark plugs I can turn the drive shaft very easily with bare hand. I have a flexible inspection camera and do not see any grooves or burns on the cylinder walls or top of the pistons. Since it is now winter and I have the time, would it be a good idea to pull the head off the engine to inspect the pistons and cylinders for any evidence of piston seizure? If I do find such evidence, how would I isolate the cause of the problem?
UPDATE:
I wanted to determine if the oil injection system was the problem. I isolated the fuel system by removing the fuel pick up line from the selector switch and running a hose into a jug with 40:1 gas. The result was the same, sudden shut off. After running out of ideas, I went back to the dealership and discussed the problem with the tech. He suggested that the CDI unit may be the problem. SO…I bought a new CDI and installed it. Same result, sudden shut off. Fortunately I was able to return the CDI to the supplier. Tired and frustrated, I took the jet ski to the dealership and ask them to try to solve the problem. I was informed that “We do not troubleshoot on SeaDoos this old”. Seems that when we cheap ol’ SOBs get work done on old units, it’s like peeling off the onion skin. They fix one problem and that uncovers another. Then the customer blames the tech for doing something wrong. Therefore I had to give a specific work order. So I said, remove the head and inspect the pistons, rings and cylinders for piston seizeure. They did, and, YIKES…Pistons were burnt, rings frozen and cylinders scored. How did this thing keep running?
The consensus was, the problem started when the oil lines to the rotary valve to mix the oil with the gas dry rotted and broke, the pistons seized for lack of oil.
I sent the jugs to Full Bore to be bored and returned with rebuild kit including pistons and rings. It took a while but it was mid-summer, their busiest time. The dealership rebuilt the top end. And, so the oil problem would not happen again, I had a block off kit installed and will mix my own gas. PROBLEM SOLVED! Not quite.
I took the SeaDoo out to the lake for its test ride. I spent quite a while putting around to break in the new pistons and rings. Then I hit the throttle and off we went….for 20 minutes, then it bogged down and shut off. (Insert bad word here).
I went back to the dealership and informed the tech, what happened. He said he had checked the carburetors when he had it tore down and they were ok for fuel mix. He mentioned that he had looked at the wear ring through the nozzle and that it looked a bit suspicious. He said he has heard of a rough hull that has been beached a lot would cause air bubbles to form and be sucked into the engine and replace some of the water for the cooling system thus causing the engine to overheat and seize. He suggested temporarily replacing the water hose with a clear hose to see if bubbles are present in the water. He also said that a bad wear ring might cause the proper amount of water that is forced into the engine to be diminished and cause the engine to overheat and seize.
It was at this point that I had an epiphany. I realized that there is a heat sender on the head and a buzzer in the handlebars. If this jet ski engine is overheating, why is the overheat buzzer not going off? I pulled the heat sensor and hung it in boiling water then checked the continuity with an ohm meter and got nothing. In case the water was not hot enough, I put the torch to it, still nothing. I checked the buzzer. It worked. The heat sensor is no longer available from SeaDoo, so I ordered a used one from Ebay.
My next project was to remove and inspect the jet pump. When I got the pump out of the jet ski, I found the wear ring to be nearly disintegrated. The play in the impeller was almost 1/2” and very little oil in the cone. I am waiting on the complete rebuild kit for the jet pump.
I think I am down to the last possibility for this problem. If someone has read this complete post and has any ideas, let me know. Thank you all for the help. I am determined to fix this thing. My grandkids are depending on it.
