Hello and welcome to the forum, if you are reading this I am able to assume that unfortunately your ski is not running as well as it should be (or at all). Let me begin by saying DON’T PANIC, there skis are just like any other mechanical device and as such do have problems. Fortunately these skis can take a severe amount of abuse (within reason) without major failure. I have personally run my 15f with a majorly rich air fuel ratio, sunk it 2 times, and run with more than 50 degrees of timing at idle. I can’t recommend this nor did I do this on purpose but when building a ski that is in uncharted waters you find things out that you shouldn’t.
This guide as you can tell by the title will cover the NON-SUPERCHARGED Kawasaki engines that power the STX models as well as the Ultra LX. Before beginning any of the diagnostics make sure that the battery is fully charged and that you have a fire extinguisher nearby. If the battery is charged but the motor will not turn over ensure that the motor is not hydrolocked (full of water) or that the jet pump bearings or impeller are not seized. If either is the case do not attempt to crank the motor any longer as damage will result. If the jet pump is locked up and you remove it DO NOT attempt to start the motor, this will damage the drive shaft support bearing and could damage the hull.
My engine won’t start:
Bad or old gas
Gas will not last forever, this is not leftist propaganda it’s the truth. Modern fuel contains ethanol and in some cases can contain up to 20%. Ethanol wicks water in and as basic chemistry teaches us water is not combustible under normal circumstances. Get a siphon out and suck the old gas out and put fresh gas in. Give it another shot on starting, if it doesn’t start move on to the next step.
Bad spark plugs
The spark plugs may still look okay but typically this is the easiest fix and fairly cheap as well, use the spark plug in the tool in in the tool kit under the seat, the top is 17mm and the wrench is also in the tool kit. Remove the plugs and replace them with P/N NGKCR9EK or CR9EIX. While you have the spark plugs out check the compression, you will need a 10mm adapter to test with. To properly check compression you need to open the throttle fully and crank the engine over for a few seconds until the gauge stops rising (it will still move but the reading will stabilize after a few rotations) As per the Kawasaki Manual, the compression for a 15f or Ultra LX should be between 172 and 260 P.S.I. What you should be looking for though is consistency between the cylinders. If you have any cylinder which is lower than the rest by a large margin or is 0 bigger problems lie beneath and you should begin more in depth troubleshooting. When you reinstall the spark plugs be sure to use ANTI-SEIZE on the spark plug threads and install with a TQ wrench and Torque to 113 In-LBS (This is important because the Kawasaki spark plug threads are fairly small and can either strip or break the plug when removing it or installing. If you feel resistance while trying to remove the plugs, stop, have a beer or beverage of your choice and spray some penetrating solution on the plug and let it sit then come back and try again) If replacing the spark plugs doesn’t get the engine to start move to the next step.
Low Or No Fuel pressure
If your engine is not getting enough fuel it will not run properly or at all, on the 12f, 15f, and Ultra LX the Fuel pressure should be 43 P.S.I. at idle or just after cranking. If the fuel pressure is low there are a few different potential causes. Just after cranking the motor over you should hear a whirring sound. If you do not hear the sound remove the fuel pump housing from the fuel tank, and check for rust on the fuel pump. If there was ever water in the fuel it could have damaged the fuel pump resulting in lower fuel pressure. You can attempt to turn the fuel pump over on the bench to verify but it is typically easy to see if the pump is dead. If you hear the pump working check the pressure just off the send line of the fuel pump. Then check the fuel filter for flow, if it is clogged it will need to be replaced. The third possible cause is a faulty fuel pressure regulator. This is on the return side of the fuel pump assembly and is a small box shaped item secured by 2 screws on the fuel pump can. This should hold up 43 psi if pressurized with an air compressor, if It doesn’t it will need to be repaired by adding some spring tension or replaced with an aftermarket external regulator. If the ski does not start at this point move on to the next step
Faulty fuel injector
While this is a rare occurrence it is possible for the injectors to degrade or become clogged, if you think that an injector may be plugged, remove the ignition coils and crank the engine over for a few seconds then remove the spark plugs, if any of them are dry the injectors are not working either due to electronic issues such as faulty wiring or a dead injector, this can be verified by removing the faulty injector and swapping it to a different cylinder. If all of the injectors are functioning properly move onto the next step.
Faulty ignition coils
The Kawasaki Ignition system is driven by what is called a waste spark system which uses 2 ignition coils to fire the 4 cylinders. The Kawasaki coils are pretty reliable but if you have reached this point this will not be comforting. Check the ignition coils by removing the spark plugs from the head and grounding them to the engine with the coils connected. (It is also a good idea to remove the fuel injector plugs as well while doing this) Then crank the engine over and check each of the 4 spark plugs for sparks. If you don’t see a spark make sure that the spark plug is grounded and if it is replace the coil or plug wire. If this doesn’t fix it move onto the next step.
Unplugged wiring, damaged connectors, damaged sensors or wrath of God.
At this point if the ski is not running you need to evaluate whether or not you should take the ski to the dealership. Before you give up and part out your ski, it is worth picking up a multimeter and testing the sensors resistance values, the cam position (400-460 ohms), crank position (408-612 ohms), and (old style non brass) temperature sensors (oil and water temp 293k ohms at 68 degrees f and 13.2k ohms at 212 degrees f) can all be tested (at least partially) with a standard multimeter. It is also worth really going through the wiring harness and looking for unplugged connections, without all the sensors plugged in nothing will happen. Throttle position, map sensor, and vehicle down sensor all require special tools to test but if you think these are problematic take it to the dealer and specifically ask for them to be tested.
Next we will go through the possible causes for poor running at idle.
Sean
This guide as you can tell by the title will cover the NON-SUPERCHARGED Kawasaki engines that power the STX models as well as the Ultra LX. Before beginning any of the diagnostics make sure that the battery is fully charged and that you have a fire extinguisher nearby. If the battery is charged but the motor will not turn over ensure that the motor is not hydrolocked (full of water) or that the jet pump bearings or impeller are not seized. If either is the case do not attempt to crank the motor any longer as damage will result. If the jet pump is locked up and you remove it DO NOT attempt to start the motor, this will damage the drive shaft support bearing and could damage the hull.
My engine won’t start:
Bad or old gas
Gas will not last forever, this is not leftist propaganda it’s the truth. Modern fuel contains ethanol and in some cases can contain up to 20%. Ethanol wicks water in and as basic chemistry teaches us water is not combustible under normal circumstances. Get a siphon out and suck the old gas out and put fresh gas in. Give it another shot on starting, if it doesn’t start move on to the next step.
Bad spark plugs
The spark plugs may still look okay but typically this is the easiest fix and fairly cheap as well, use the spark plug in the tool in in the tool kit under the seat, the top is 17mm and the wrench is also in the tool kit. Remove the plugs and replace them with P/N NGKCR9EK or CR9EIX. While you have the spark plugs out check the compression, you will need a 10mm adapter to test with. To properly check compression you need to open the throttle fully and crank the engine over for a few seconds until the gauge stops rising (it will still move but the reading will stabilize after a few rotations) As per the Kawasaki Manual, the compression for a 15f or Ultra LX should be between 172 and 260 P.S.I. What you should be looking for though is consistency between the cylinders. If you have any cylinder which is lower than the rest by a large margin or is 0 bigger problems lie beneath and you should begin more in depth troubleshooting. When you reinstall the spark plugs be sure to use ANTI-SEIZE on the spark plug threads and install with a TQ wrench and Torque to 113 In-LBS (This is important because the Kawasaki spark plug threads are fairly small and can either strip or break the plug when removing it or installing. If you feel resistance while trying to remove the plugs, stop, have a beer or beverage of your choice and spray some penetrating solution on the plug and let it sit then come back and try again) If replacing the spark plugs doesn’t get the engine to start move to the next step.
Low Or No Fuel pressure
If your engine is not getting enough fuel it will not run properly or at all, on the 12f, 15f, and Ultra LX the Fuel pressure should be 43 P.S.I. at idle or just after cranking. If the fuel pressure is low there are a few different potential causes. Just after cranking the motor over you should hear a whirring sound. If you do not hear the sound remove the fuel pump housing from the fuel tank, and check for rust on the fuel pump. If there was ever water in the fuel it could have damaged the fuel pump resulting in lower fuel pressure. You can attempt to turn the fuel pump over on the bench to verify but it is typically easy to see if the pump is dead. If you hear the pump working check the pressure just off the send line of the fuel pump. Then check the fuel filter for flow, if it is clogged it will need to be replaced. The third possible cause is a faulty fuel pressure regulator. This is on the return side of the fuel pump assembly and is a small box shaped item secured by 2 screws on the fuel pump can. This should hold up 43 psi if pressurized with an air compressor, if It doesn’t it will need to be repaired by adding some spring tension or replaced with an aftermarket external regulator. If the ski does not start at this point move on to the next step
Faulty fuel injector
While this is a rare occurrence it is possible for the injectors to degrade or become clogged, if you think that an injector may be plugged, remove the ignition coils and crank the engine over for a few seconds then remove the spark plugs, if any of them are dry the injectors are not working either due to electronic issues such as faulty wiring or a dead injector, this can be verified by removing the faulty injector and swapping it to a different cylinder. If all of the injectors are functioning properly move onto the next step.
Faulty ignition coils
The Kawasaki Ignition system is driven by what is called a waste spark system which uses 2 ignition coils to fire the 4 cylinders. The Kawasaki coils are pretty reliable but if you have reached this point this will not be comforting. Check the ignition coils by removing the spark plugs from the head and grounding them to the engine with the coils connected. (It is also a good idea to remove the fuel injector plugs as well while doing this) Then crank the engine over and check each of the 4 spark plugs for sparks. If you don’t see a spark make sure that the spark plug is grounded and if it is replace the coil or plug wire. If this doesn’t fix it move onto the next step.
Unplugged wiring, damaged connectors, damaged sensors or wrath of God.
At this point if the ski is not running you need to evaluate whether or not you should take the ski to the dealership. Before you give up and part out your ski, it is worth picking up a multimeter and testing the sensors resistance values, the cam position (400-460 ohms), crank position (408-612 ohms), and (old style non brass) temperature sensors (oil and water temp 293k ohms at 68 degrees f and 13.2k ohms at 212 degrees f) can all be tested (at least partially) with a standard multimeter. It is also worth really going through the wiring harness and looking for unplugged connections, without all the sensors plugged in nothing will happen. Throttle position, map sensor, and vehicle down sensor all require special tools to test but if you think these are problematic take it to the dealer and specifically ask for them to be tested.
Next we will go through the possible causes for poor running at idle.
Sean
Comment