FastMarkA
Active Member
When I got my new-to-me 300 SLX last season, it had 100 hours. At WOT, it would easily reach 52-53 MPH @5000-5100 RPM.
Since the boat is >3 years and over the 100 hour mark, I decided to do a tune-up towards the end of last season: plugs, caps, rotors, distributors, fuel filters, water impellers, and oil/filter changes.
It accelerates much more smoothly than before (although it was never bad by any means), but now, I can easily hit the rev limiter at 5200-5350 RPM, but my WOT speed is 50.6 MPH. (And yes, the Smart Craft alarms go crazy...as they should.)
Before the tune-up, I would never come close to the rev limiter, so that tells me the engine is firing better with the new plugs/equipment? What puzzles me is that nothing in the underwater gear has changed, but I'm losing 2 MPH. (The boat was in a heated garage over the winter and has a clean bottom.)
So my questions are: (1) any thoughts as to why I'm losing 2 MPH and (2) maybe the added power means I should upgrade from 24P to 25/26P props?
(Of course, within all of this, I fully recognize losing 2 MPH off the top end, a speed I hit maybe 3-4x a season, is not the end of the world...it's more puzzling than anything.)
Since the boat is >3 years and over the 100 hour mark, I decided to do a tune-up towards the end of last season: plugs, caps, rotors, distributors, fuel filters, water impellers, and oil/filter changes.
It accelerates much more smoothly than before (although it was never bad by any means), but now, I can easily hit the rev limiter at 5200-5350 RPM, but my WOT speed is 50.6 MPH. (And yes, the Smart Craft alarms go crazy...as they should.)
Before the tune-up, I would never come close to the rev limiter, so that tells me the engine is firing better with the new plugs/equipment? What puzzles me is that nothing in the underwater gear has changed, but I'm losing 2 MPH. (The boat was in a heated garage over the winter and has a clean bottom.)
So my questions are: (1) any thoughts as to why I'm losing 2 MPH and (2) maybe the added power means I should upgrade from 24P to 25/26P props?
(Of course, within all of this, I fully recognize losing 2 MPH off the top end, a speed I hit maybe 3-4x a season, is not the end of the world...it's more puzzling than anything.)