2007 GTX Wake 215hp only goes 45mph

[haushering]

I own a 2007 GTX Wake edition that used to go 70 mph on a flat lake now only reaches around 40 mph. One owner, winterized every year, fresh plugs and recently replaced the starter solenoid successfully. The instrument cluster is shattered due to rough lake weather but otherwise the PWC is in good shape. Anyone have specific suggestions how I may be able to gain some performance back? I understand the ski is old but unsure what is realistic to expect if all parts were working proper. Any feedback on expectations for performance if all in good order, and suggestions how to improve greatly appreciated.

 

[PeterC4]

Have you checked the wear ring? A drop in top speed may be caused by some cavitation. I have found that a new wear ring helps restore top speed. Your GTX can do 70 mph? That's as fast as my RXT 300.

 

[haushering]

Thanks, I'll gladly look in to the wear ring.
When the craft was new and the digital cluster worked it would log top speed to be re-viewed; early on, more than once it stored 72 mph. Granted, the ski may have been traveling 60-65 most of the time- on flat water, mind you- and it caught a miniature uptick in speed that didn't reflect its sustainable overall output. Now, by and large the range of speed of 45+ is unreachable which makes sense on some level because of its age, but I would figure given the amount of HP, etc. 50-55 wouldn't be unreachable. Since the ski is so large and heavy it is the difference in being able to launch off lake waves when they're 3-5 ft. Appreciate the feedback, more is welcome.

 

[skiasylum]

Can you read RPM’s anywhere, maybe not if your cluster is f........Low RPM engine or supercharger, normal RPM low speed probably driveline

 

[haushering]

Can't ready RPM's unfortunately.

 

[haushering]

I think the engine is supercharged

 

[skiasylum]

It is, if it feels like it’s spinning its wheels it’s driveline if it feels weak and the tires aren’t spinning it’s the motor or supercharger. If you think it’s supercharged that probably means the supercharger hasn’t been rebuilt in the last 100 hrs or 2 years which is recommended. The supercharger clutch can be tested it needs to pass a torque test.

 

[haushering]

Yes I believe supercharged. Definitely 215 hp. This is a generic picture of the side of ski
We've never rebuilt supercharger and it is 12 years old. This would cause the drastic decrease in performance over time? Makes sense.

 

[noviceskier]

I think the drastic decrease in performance would be because that supercharger is a grenade is could've already gone off.

 

[skiasylum]

Think your next step would be to take off the supercharger and make sure all the parts are intact, if any clutch washers or bearings are missing means there in the engine somewhere and it would need to come apart. If all the parts are where there supposed to be and your driveline and engine check out good send it to PWC Muscle and get it rebuilt and maybe not wait 12 years next time.