Bravo II 5.7
 

Ok, we are having some disbelief but I am having a rpm issue with my 26 Crownline.250hp 5.7 Bravo II 2.2 with a stock 21p 3 blade aluminum.She is a medium cruiser and weighs in about 7k loaded up or there about.

She planes off a dead idle with tabs and drive tucked in about 5-8 seconds with about 80%.Problem here is she is spinning near 5k at that point.She will not hold plane unless you are over 4k...4200 and you get about 30ish on the dash speedo.

here comes the interesting part.We question the tach as my idle is about 800rpms.Seems right then...I roll her out to about 4k and just put the throttle down..within about 10 seconds and little trim she is fukin spinning 5600rpm and I pull her back.She wasn't done and wasn't showing signs of party over.Totally floored as to why a 5.7 wouldn't float the valves I see the speedo just a hair under 45mph..That is friggin gettin the doggy in this tank.I back her down to 4k and she is at 30ish again....WTholyF?.....How is this heavy ass boat unpropped with a 21p 19.75 fan blade?..It is massive!

We almost think that tach is telling a tall tale...she just pulled and pulled no problem...my buddy has 377's in his 29PC and he looked funny at me when we got to the dock but noticed I was right behind him and he runs 46mph on GPS...I had a witness to prove it..who told me to slow the F down.

Can this thing run a 23p?...I wanna run a SS but it is a BII so the choices I find are are kinda pricey..

Re: Bravo II 5.7
 

No?...I'm high again? :drink:

Re: Bravo II 5.7
 

How ya doin? Id get a good tach on it first to find out what is realy going on. Otherwise, dont know much about B-2 props. Its not blowing out right? If its turning 5k at planing load you must have 1000 hp in that 350. My quess is the tach is fubar.

Re: Bravo II 5.7
 

I'm pretty sure I could flat throttle it and blow it out..I really just lay down about 30% to get her moving and then quickly to about 80% and she is up on plane.But you're looking at 4k fast.Stays right there but just touch that throttle a itsy bit and she falls right off plane...enough that it is hard to correct without being ready for it.

From say 4200/30mph and lay her down she pulls hard to 5600/45mph..still wanted to go I just pulled the throttle back in pure fear of something letting go..Looking like I am under-propped...maybe a 23 3 blade SS and see what happens.