New impeller & Wear Ring ...... 7000 rpm max

[Scrubbs]

Hi all, I need to pick the brains of the specialists on here.

So at the end of last year I sucked up a few rocks that killed the 155 GTX's wear ring and impeller. Fixed it this year, and bought a 155 Wake to add to the family. Last year, the GTX had a top speed of 87kph, and this year it only does 80. I can't remember what the max rpm was last year, but this year it's 7000 rpm. Prop is a stock OEM from the BRP dealer.

I have had all four keys programmed to start either machine, and trying different keys in the wake has resulted in no loss of rpm to it. As well, all four keys in the GTX have it running at the 7000 rpm mark. I'm stumped... Same fuel being run in each.

Any thoughts?

Thanks

 

[Coastiejoe]

You mentioned a new impeller

is it the same pitch as you had or different?

 

[KK40384]

You mention the prop is stock oem from BRP. Could it be that it is one for the SC GTX models instead of the 155? That would cause your problem. Cross reference the part numbers for your impeller and the one you just bought to see if they got you the right one.

 

[Scrubbs]

Thanks for the replies.

I looked into the part number, and the one on the invoice is 267000492, which does match the BRP Parts catalogue for the right year and model.

 

[Coastiejoe]

Thanks for the replies.

I looked into the part number, and the one on the invoice is 267000492, which does match the BRP Parts catalogue for the right year and model.

Does that also match the one you removed?

 

[Scrubbs]

I think so, it was the stock impeller.....

 

[KK40384]

Is it possible that the rubber cone on the impeller was loose and came off on the driveshaft? That shouldn't cause rpm loss but it will kill your top speed and acceleration. I'm just trying to pick my brain here because the pump is the only place you did any work so that leads me to believe that's where the problem lies.

 

[Dr Honda]

Thanks for the replies.

I looked into the part number, and the one on the invoice is 267000492, which does match the BRP Parts catalogue for the right year and model.

I think so, it was the stock impeller.....

This is a problem. (sort of)


If you want to know for sure... the part number is on the impeller. That's the number you need. Not the one from the invoice... and you can't "THINK" it's the right one. From your ski... you are only off by a few MPH/KPH and a few RPM low. SO... when looking for a minor problem... you have to verify, 100%. Besides... the possible loss you are seeing could simply be from hot humid air. OR... the ski is carrying a little more weight. (either the rider, or equipment)


Also... are you looking at the speedometer on the ski? They don't read right normally, and as the little wheel wears, it could chatter, and give you a lower indicated speed. So... unless you are checking with a GPS... the speeds are too close.

And finally... since you don't know what your RPM's were like last year... we don't have a reff to go from, to know if you really have a prob.



I'm not trying to be harsh... but after reading over this... I'm not convinced you have a problem. (other than something doesn't seem right) If this was my ski... I would verify the pitch, and I may take 1/2 ~ 1 degree out of the pitch to help bring the PRM's up closer to 7200.



With that all said... I'm assuming your peak RPM is 7300. But, I will go check the red-line for your ski. But even if it's higher... all the above still holds true. You can't guess, when looking for an issue.

 

[Scrubbs]

No worries Doc, one can't ask for help, and then get mad at the answers....

The speed was taken from the gps on the dash, as these models use the gps rather than the wheels. The stock impeller has no numbers other than a QC, 432,1. So I am not sure if the 432 should read 492 on the prop? If I am only loosing 2-300 rpm, not a huge worry, I thought I was loosing more, hence, asking the questions.

Could also have been the fuel, which was sitting for a while over the long winter. Running better fuel in it last night, and although had another passenger, still ran pretty good.

Thanks to all who replied, not going to worry about it anymore.

Cheers!

 

[Andrew_lbreman]

Just a comparison I bought a prop for a ski i was rebuilding and they swore it was the proper item number but i had lost power and so I pulled the impeller and it was for a different ski. I sent it back and they got me the right one but still had to pull the pump and check the numbers exactly.