Popping at 5000 RPM

[Tboneaz]

I just had a new 5.7 volvo pinta moter put in mt 1999 230 Bow Rider. I gained 30 HP but we did have to rejet the carb. I still get a bit of popping at 4800 to 5000 RPM @ 42 MPH. The Boat Shop sugested I go from a 13X19 prop to a 13X21 prop. I am hoping to get more speed out of this prop and less RPM. Any thoughts???

 

[Bondo]

Re: Popping at 5000 RPM

Ayuh,... Sounds like ya Need the 21" prop...

 

[Tboneaz]

Re: Popping at 5000 RPM

Picking it up today I will let you know if it works lol.

 

[wellcraft19]

Re: Popping at 5000 RPM

Just for reference, I have a 19 foot Wellcraft with an AQ171C (2.5 liter, I-4 DOHC engine) - which is MUCH smaller than what you have (high revving engine with 167 hp)
With a 2.15:1 gear ratio in the drive, I've been running 3-blade 14x19 and 14x21. 14x19 seem to be the perfect size, 14x21 increases top speed a bit, but barely allow engine to rev out (though OK with only me a dog onboard).

I'd say you have far too small prop even with 13x21...

(and just for trying, I have a new 14x17 4-blade on order, to arrive early next week).

 

[Tboneaz]

Re: Popping at 5000 RPM

I purchased a 14 1/2 X 21 new prop and it works like a champ. I also found out from a new boat shop I am now going to, the popping was the rev limiter not a fuel issue. After going to the new prop the popping stopped I am now at 45 MPH 4800 RPM right where I need to be. Thanks to Lloyds Marine in Mesa AZ. Good group of guys very knowledgeable.