290 sc
#41
ok guys a question. im now spinning a 26 4 blade bravo. huge difference in handling and everythin. so, im now maxing out at 5000 rpms on the dot but my speedo wont go above 55. am i running around 70 at 5000 with that prop math wise? speedo may have to be looked at? just seems wierd im only getting 55 at 5000 WOT. any ideas?
#43
Registered
A 26 running 5000 should be 70 or just over. The tachs are also know to read a tad higher as well.
#45
Registered
The speedo is nothing more than a calibrated water pressure gauge - the faster you go the harder the water is pushed into the gauge. Assuming your tach is reading ok (if it's a Faria they can act up and read 500 RPM high), I'd suggest checking your speedo line to the gauge. You can incrementally pressurize the speedo line to see how smoothly the guage needle moves. I'd use a small hand operated air pump connecting to the speedo hose at the Bravo drive disconnect . If the external rubber speedo hose is leaking pressure your speedo will read low. Or just borrow another speedo (or buy a used one cheap on ebay) for testing purposes.
Last edited by Revelocity; 10-02-2019 at 02:31 PM.