SeaDoo Supercharger with ET137 Not getting boost


I can only get 11-12 pounds of boost. SC is slipping at 17ftlbs.

I have a candoo Air fuel/ boost reader
I do have a maintenance code that appeared after i tightened the supercharger

Can you list the checks i should perform to figure out what is going on?


What would happen if the slip is to high


Too high and it is harder on the shaft and gear. Luckily the ET137 is pretty light, so you aren’t in a bad spot.

You said maintenance code? Or engine light? Lets get that resolved first to make sure it is unrelated. Any other codes?


The tuner says no engine codes are present.
The dash says manti


Ok that is just the normal hour-based maintenance warning.

What rpms are you maxing out at?




Which intercooler and did you do the ribbon delete? You are getting close to the advertised boost pressure at that RPM if you are hitting 12psi…suppose to be 13-13.5.


I have the fizzle and there is no ribbon in the intake.
I have hard pipes and currently no blow off valve
I have canaflex intake
I have the intake girdle
I’m only getting 68-69 mph which is extremely did appointing


Which tune is installed?

And which pump impeller?


i have a custom tune. Jesus has not been able to get me a good tune yet.
i have a 14/19 impeller that you guys advised me to get


Yeah you should be well over that speed with that impeller and a tune for sure. So since you are working with Jesus, I’m going to assume the tune is at least decent.

Check for boost leaks. There might be one and itd affect your boost at higher levels, thus robbing you of power on the top end. If completely free of leaks, I’d look at the tune next.

And of course as a quick ease-of-mind, change and gap your spark plugs.


The tunes are ok most of them are really rich.
What size are the intercooler pipes i want to get the test plug. do i need to plug the exhaust also
What should the gap be on the plugs.
Last night i had a tune that would run 8400. It was choppy. when i go to smooth water across the lake it would only turn 7600. and even when it was getting to 8400 there was some surging in the the 7000 rpm range. then it would kick in and get to 8400.


Plugs should be .030. When you got to 8400, did you happen to notice the boost level?

The 215 pipes are 2.5", the 260 are 2.75"


It looked about 12-12.5. It was not flat water so it was bouncing


Ok likely not enough time to build the boost then. Go for the leak test and let us know!


What do you think about getting 8400 then after going a couple miles only getting 7800 rpm


I think that there is a gremlin. Boost leak, rrfpr fault, bad plug, etc etc. You shouldnt be heat soaking, and even at that youd still see more consistent performance.

While you’re in there, double check the slip on the supercharger again just to make sure.


And just to ask, the fuel is good/newish and at least 91 octane?


Yes 91 atleast every time. I ride.
Found a leaky spot in the front intercooler replacement cap.


Sounds like a good culprit. Let me know how it goes after getting it sealed up.