1988 sr1 272 prop question
06-10-2017, 09:28 PM
#21
'05 Concept SF23
VIP Member
You have a bottom rocker at the stern of the boat. Check with a straight edge. Also you might want to try some Hydromotive 4 blade props for some stern lift. They really helped my 311. Get some base lines with the 21 and 23 props and give them a call
06-11-2017, 10:37 PM
#22
Registered
I did end up switching to carbs but I still pull the same RPM's as before. Only reason i changed is because I was having trouble with keeping the motors from stalling at low RPM's and nothing I did seemed to fix the issue. The EFI was very cool but the fact of not being able to accurately diagnose the issue and then even if I did figure it out most of the parts are no longer available made it a pretty easy decision.
06-12-2017, 09:00 AM
#23
the boat came with a pair of 21 mirage props that I ran for a very short while. I had a 23 mirage that I ran on my Checkmate and found a matching prop so i switched to the 23's. I'd like to tryna pair of 23 mirage pluses but not having counter rotating drives makes finding props a bit harder (aka more expensive..)
I did end up switching to carbs but I still pull the same RPM's as before. Only reason i changed is because I was having trouble with keeping the motors from stalling at low RPM's and nothing I did seemed to fix the issue. The EFI was very cool but the fact of not being able to accurately diagnose the issue and then even if I did figure it out most of the parts are no longer available made it a pretty easy decision.
I did end up switching to carbs but I still pull the same RPM's as before. Only reason i changed is because I was having trouble with keeping the motors from stalling at low RPM's and nothing I did seemed to fix the issue. The EFI was very cool but the fact of not being able to accurately diagnose the issue and then even if I did figure it out most of the parts are no longer available made it a pretty easy decision.
Also when you had the 21s on there what was the MAX rpm you got? thanks
06-12-2017, 11:27 AM
#24
Registered
I haven't noticed any performance loss at all switching to the carbs. I used Edelbrock RPM Air Gap intakes and QuickFuel Marine 650cfm carbs. Throttle response is very crisp and low RPM manners are fantastic now.
I only ran the 21 props the boat came with a handful of times and never ran them out to see how high they would go. I backed off after it was over 5500 rpm and that was around 63-65mph depending on conditions. With the 23 mirages I am right around 5300 RPM but that is with full fuel and 4-5 people on board and a couple coolers. I would like to prop the boat for a max of 5200-5300 with low fuel and just myself on board. I would really like to try a set of 23 mirage pluses to see how it performs.
I only ran the 21 props the boat came with a handful of times and never ran them out to see how high they would go. I backed off after it was over 5500 rpm and that was around 63-65mph depending on conditions. With the 23 mirages I am right around 5300 RPM but that is with full fuel and 4-5 people on board and a couple coolers. I would like to prop the boat for a max of 5200-5300 with low fuel and just myself on board. I would really like to try a set of 23 mirage pluses to see how it performs.
