07-13-2014, 07:34 AM #1
I have changed my impeller, same water temp was running a 15/20r @8060rpm
I installed a 15/19r and now it's turning at 8500rpm...
I don't understand... First, there something grinding when going at low speed and doing hard turn (carbon seal or shaft alignment?)
Is it possible that it's doing cavitation? 1mm and I turn 500 more rpm...
I have a 8375 tune, and it's turning way over... I don't go at WOT for a long time... I haven't change the valve retainers...
Thanks for your help!
07-13-2014, 10:39 AM #2
Check to be sure pump seal didn't get pinched throwing off alignment.
07-13-2014, 10:46 AM #3
My dealer installed the impeller ... I'm not sure where the pump seal is... Let me check in the shop manual.
07-13-2014, 10:57 AM #4
Did you make sure both props were measured before? My 15/20R was really a 15/19 straight from RIVA. Just because it is stamped one way doesnt mean that it is the actual pitch.
07-13-2014, 11:11 AM #5
To be honest... No... This lead me to another question... Running a couple seconds over 8375 rpm on the stock retainers... Is it bad... A couple second I mean like 5 or 10 seconds...
I plan to do the retainers at the end of the summer... I'm not always at WOT... Normally cruising around 4500-5000...
07-13-2014, 01:15 PM #6
I would also like to know ^^. I plan to run 8200-8375rpm range once prop dialed in on stock valve train. Is it safe? Old threads show 8400+
07-14-2014, 11:42 AM #7
@Green Hulk I would love to have your input on this one! Thanks!
07-14-2014, 04:27 PM #8
07-14-2014, 04:40 PM #9
My question was more... Is it safe to run over 8375rpm for a couple seconds...
My other question is that I switch from a 15/20r to a 15/19r and I jump about 600rpm... From 7900 to 8500... Is it normal to gain that much or there's something wrong with something else... A seal or something else... I check my wear ring and it's perfect... I don't understand... I taught 2 500rpm more but not 600...
07-14-2014, 05:01 PM #10
- Join Date
- Aug 2010
I bet that the 15/20r was not all 20's on the trailing edge...
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