Superjet bogs out when in water, has no issue on lift

J

JustGood

X-H
Location
Allegan, MI
superjet bogs down after a minute of riding(basically a limp mode, where I could swim faster than its moving). I put it on the lift and it will rev up fine. Put back in water and limp. Tried plugs, splashed water on the motor, bpipe, exhaust chamber, not over heating. I have removed the heat sensor from the head. any ideas on why it doesn't have enough power in the water to move but is fine on the lift? I appreciate the help. 49010
 
ryan0

ryan0

Location
kent island maryland
Iv seen that happen when a head or head gasket or a exhaust manifold is bad causing water ingestion. you can test it by temporarily kinking the water line and putting a wire tie to hold it kinked to the engine do a quick hole shot and shut it down so it doesn't over heat if it takes off you know you have water ingestion problem.
 
surfjunkie

surfjunkie

Location
deland fl
if the overheat sensor is bad it will still limit the engine even when removed from the head cause its reading a false signal that the engine is hot even when its not so it could be sitting in a bucket of ice and still limit revs. i think the contacts corrode together or something like that. but if it revs up fine out of the water that doesnt sound like your problem. i think it would still bounce off the limiter out of the water
 
Pro-pulsion

Pro-pulsion

Location
Ontario, Canada
Do a coil test, sounds like the secondary winding is failing under load. This has been the single most common issue I have experienced with Yamaha electrical parts. It is also one of the fastest tests and easiest you can do. One test probe per spark plug boot and test resistance values. Specs say 3.5 - 4.7 k ohms.

I should add, if you get higher values than spec, first try trimming the leads back about 3/8" and test again. Sometimes high tension leads will burn out internally close to the hot spark plug. The wire inside turns into a fine soot that is semi-conductive acting like a resistor giving higher than normal readings. But from what I have seen so far, with Yamaha coils this has not been the case for me. It has always ended up being a failing coil.
 
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J

JustGood

X-H
Location
Allegan, MI
Tried pinching the intake water. Still bogged out. Replaced the one way valve. Still nothing. I'll try the coil test. I appreciate the input. Frustrated is an under statement compression is also good


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J

JustGood

X-H
Location
Allegan, MI
Pro-pulsion said:
Do a coil test, sounds like the secondary winding is failing under load. This has been the single most common issue I have experienced with Yamaha electrical parts. It is also one of the fastest tests and easiest you can do. One test probe per spark plug boot and test resistance values. Specs say 3.5 - 4.7 k ohms.

I should add, if you get higher values than spec, first try trimming the leads back about 3/8" and test again. Sometimes high tension leads will burn out internally close to the hot spark plug. The wire inside turns into a fine soot that is semi-conductive acting like a resistor giving higher than normal readings. But from what I have seen so far, with Yamaha coils this has not been the case for me. It has always ended up being a failing coil.
Click to expand...

This is how much of a beginner I am, when you say coil are you referencing a bad stator or ignition coil? Also, what type of tool do I use to perform this test? Ohm meter?


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Pro-pulsion

Pro-pulsion

Location
Ontario, Canada
Yessum, ohm meter. I would say you are not that much of a new guy to it if you are asking about stator coils ;) But for this test you can go higher up on the engine, as mentioned put one test probe in one spark plug boot touching the inside metal cap, and the other probe in the second spark plug boot the same way. Set your ohm meter to read in the lowest K ohms option you have to look for the mentioned values.

Oh, before I forget, yes this test is for the ignition coil. Any stator coil tests would be referred to simply as test the stator due to those coils make up the complete stator and are tested at the same time when inside the electrical box (or ebox for short).
 
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