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Impeller pitch

SVTSINR

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Thanks, the PDF says 161 mm for 165/195 but 159 mm for 215/255 so this will be interesting. I will have to see how the wear ring fits and if it makes up the difference.
 

jetboy

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Thanks, the PDF says 161 mm for 165/195 but 159 mm for 215/255 so this will be interesting. I will have to see how the wear ring fits and if it makes up the difference.
If you look in the product information guide under Scarab 195 /Page 10/ Performance your Impulse has the ROTAX 250/187 1.5L Supercharged HO engine with the 161mm impeller. The non-HO with the ROTAX 200/149 1.5L Supercharged has the 159mm impeller.

Sorry for the confusion again. Let me know if I can help!
 

Faith Johnson

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No. I just replaced mine with 159 mm. I got pitch 14/19. I also have the 195 HOI. I went with the steel wear ring and gained 5mph in speed.
 

jetboy

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No. I just replaced mine with 159 mm. I got pitch 14/19. I also have the 195 HOI. I went with the steel wear ring and gained 5mph in speed.
Faith, congrats on the gains!

Bear in mind that @SVTSINR asked about factory replacement. That is the reason I referred to the product information guide for sizing. Unless the guide is wrong the HOI's have a factory 161mm impeller. That is not to suggest the 159 mm impeller would not work (as in your case).

Did you get the Solas SRX-CD-14/19?
 

Faith Johnson

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@jetboy you're right. Do you think it'll hurt it with the 159 mm? I've been running it for about 5 hours total on my boat and haven't seen any negative aspects.
 

jetboy

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@Faith Johnson No. I don't expect that you will have any problems at all. Your setup will be fine, if not it is better- as you mentioned already noticing performance gains!

I am a little surprised though that going from a 161 mm to a 159 mm (14/19) gave you a performance increase given the good power of your engine. It seems that the shorter prop would be less efficient as it would have to turn more to pump the same volume of water out.

That said, regardless of the expectation- if your getting great performance that's all that matters!!
 

Faith Johnson

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@Faith Johnson No. I don't expect that you will have any problems at all. Your setup will be fine, if not it is better- as you mentioned already noticing performance gains!

I am a little surprised though that going from a 161 mm to a 159 mm (14/19) gave you a performance increase given the good power of your engine. It seems that the shorter prop would be less efficient as it would have to turn more to pump the same volume of water out.

That said, regardless of the expectation- if your getting great performance that's all that matters!!
Well you have to know why I switched in the first place. It was going slow and with 6 people, wouldn't go over 10 mph. I'm getting around 47 mph with 2 adults. Is that normal?
 

jetboy

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....."It was going slow and with 6 people, wouldn't go over 10 mph....
Are you serious about the 10 mph??? That is not normal at all for 6 average sized (+/- 200 lb) folks! Perhaps you had a seriously damaged impeller and the change out made the difference?
 

Faith Johnson

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Yea the wear ring was in bad shape but the impeller looked ok. I think it was from shallow sandy areas like crab island. It's also not recommended to Beach it and I had a week before this started. I'm just glad the 159 mm is ok. I was beginning to wonder if it was going to slide out. Thanks so much for your help and quick response.
 

SVTSINR

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FYI, I measured my prop and it's 159 mm. The 161 mm is new for Seadoo 2016 so I don't believe Scarab would have introduce them ahead of Seadoo production. I ordered the 15/20A so I'm curious how it compares with Faith's 14/19 results.
 

Faith Johnson

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FYI, I measured my prop and it's 159 mm. The 161 mm is new for Seadoo 2016 so I don't believe Scarab would have introduce them ahead of Seadoo production. I ordered the 15/20A so I'm curious how it compares with Faith's 14/19 results.
I did TONS of research before I bought one. Based on different threads I read, I got it because it said it would go fast with a heavy load. I topped out at 43 with 6 full 200lbs adults (give or take lol) and 50 lb child. The conditions wasn't perfect but it wasn't bad either. I'm glad you reported back. I was sweating bullets there for a minute. Let us know how yours does. I was surprised how easy it was to install. The hardest part was getting the new wear ring in.
 

jetboy

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FYI, I measured my prop and it's 159 mm. The 161 mm is new for Seadoo 2016 so I don't believe Scarab would have introduce them ahead of Seadoo production. I ordered the 15/20A so I'm curious how it compares with Faith's 14/19 results.
Good find @SVTSINR. The information that I provided in the link was for 2016's. Before then it does appear that they (SeaDoo) pumps were sized 155 mm and 159 mm. If both of your boats are 2014 models the 159's make complete sense. Eager to hear performance comparisons as well.

Thanks!
 

ScarabMike

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All, this has been covered in here hundreds of times. The 250's have a 159mm impeller and wear ring. The Scarab site is incorrect.
 

ScarabMike

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Also, for you tech geeks out there. The 161mm pump from seadoo's new 300 hp skis will fit in a 159mm pump from the older engines/pumps. The 2 mm difference is in the wear ring itself. So, you can install a new 161mm impeller on your boats if you buy a 161mm wear ring.
 

jetboy

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Also, for you tech geeks out there. The 161mm pump from seadoo's new 300 hp skis will fit in a 159mm pump from the older engines/pumps....
@ScarabMike Did you mean that the 161 mm impeller will fit in the 159 mm pump housing as long as the wearing is 161 mm? That is correct since OD of the wear rings are the same, right?

Thanks!
 

ScarabMike

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Yes, the 161mm impeller will fit the 159mm pump if you purchase the 161 wear ring.
One other difference is that Seadoo added a set screw to better hold the wear ring in place ( presumably so it does not spin if you suck in debris ), its a 10-32 X 3/8in. The 300 wear ring is less thick and must be a higher risk to spin in housing.
 

Faith Johnson

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Have you done this yet? This could possibley give more mph. Someone needs to try this and report the difference.
 
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