prop problem

[carsflame]

hi everyone i have a 2000 2800 with 2 4.3 bravo 2 drives the props are 21/173/4 the boat motors are running great but on the water i only get 3000 rpm out of both engines cant get boat to plane does any one no the right prop pitch pls help dave thx

[mmwjr]

Not sure what this boat came with but wondering is that 21 inch diameter correct as I thought the BII could only swing a 20 inch prop.

Dropping the pitch by one inch will give another 200 rpm but you are 1600 rpm off of WOT. Is the bottom and drives clean? Did this boat ever run better for you?


Ok from your other post I see the first number before is the pitch. Look at m response to you post under engines

[carsflame]

ya everything is super clean first time i had boat in water i was at mercury dealer today he said for sure its b11 he doesnt understand the pitch he said the person who had the boat before might of set it up for a fishing boat?i dont no about that i am going to call mercury and see what they say,i did call holley marine i think they are in the top of virginia i asked the service adviser about what prop might be on the boat and he said 21/173/4 "wow" i wasnt ready for that i just need to find out the right prop thats going to work ,do you know if 4,3 motors turn clockwise thx dave

[mmwjr]

The engines are both standard rotation the counter rotation is done in the out drive.

The correct way to state the prop size is 17 3/4 x 21 with the first number being the diameter and the second the pitch.

A pitch of 21 inches seems like a lot for a 4.3 engine.

[carsflame]

ya i no better i let you no what happens thx

[ss3964spd]

Holley Marine, Dave? Do you mean Holley Acers in Woodbridge? Are you in Northern Va? Where do you keep the boat?

If you go to the Merc website I believe they have a prop calculator.

Dan

[fbhvelocity]

I have a similar setup in my 2800 fra 2000. T 4.3 B2 I recently checked out If you are running the stock B2 drives they should be 2:1 Ratio and turn 18.25x19" or 17.75 x 21" depending on the HP of your 4.3 Mine is a 2bbl carb with 190hp and a 4bbl should make 210hp and turn a 21" prop. To know the gear ratio of the drive is importent factor.

[mmwjr]

cars based on the info from fbh.... you are proped for a 4.3 with a 4 bbl carb. is your engine a 4 bbl? Also verify the B2's are 2:1 gear ratio which means the prop will do one rev for every 2 revs of the engine.

[carsflame]

hi i talked to a couple of mechanics today they don't think it is a prop problem, only one did.They thought maybe fuel ???? the boat should have a 19 pitch motor doesn't have enough power i'll working on it

[carsflame]

hi can anyone with a 2000 2800 twin 4.3 190 hp tell me please what propeller pitch they have and mph&rpm thx dave i have been told alot of different sizes thx daVE

[shrew]

Originally Posted by carsflame

hi can anyone with a 2000 2800 twin 4.3 190 hp tell me please what propeller pitch they have and mph&rpm thx dave i have been told alot of different sizes thx daVE

I merged this duplicate thread to the older post. There is no reason to have two threads. Gathering data from other boats is not the proper way to approach this problem. It was stated a bit earlier to go to the Mercury Prop Calculator and determine what mercury says. Some folks have asked for specifics such as 2bbl or 4bbl. gear ratio, HP, etc. That will all help you in calculating the proper prop range for the boat.