searay 270 weekender 454 bravo 2 not reaching 4600 rmp help

[bolo78910]

hello everyone , here I have a 1992 sea ray 270 weekender , 454 big block carter carburetor bravo 2 outdrive.

since owning the boat it never reaches max rpm, right now max rpm is 4000 , with half tank off gas only me on board.
the propeller is a 21 pitch 3 blade in great condition, the hub is not slipping , plugs wires rotor are all new , dist cap is old ,.
the upper drive ratio gear tooth count is 27 32 which is a 2.0 the lower half I bought from ebay , could it be I have the wrong lower half gear ratio. how can I check the lower to make sure it is a 16/17 gear set in it?

lastly how many ratio are available for a bravo 2 lower unit?
if I should get a bravo 3 lower what should the lower ratio be ??

I don't see why a bravo 2 cant turn a 21 pitch prop over 4000 rpm , thanks for any help in advance .

 

[Bondo]

I don't see why a bravo 2 cant turn a 21 pitch prop over 4000 rpm

Ayuh,...... That's Huge prop,....... what's the diameter of it,..??

A Bravo I would be 'bout 14" +,......

 

[bolo78910]

thanks bondo I think its 17 x something diameter I will take a look tomorrow, but am sure its 21 pitch stainless

 

[bolo78910]

could this be apart off my problem. when I first change the spark plugs I think they were gap 0.40 i install new mr43t and gap them at 035 would this make a different.

 

[Scott Danforth]

not enough to notice. spark should be able to jump at least 0.060" without a problem

 

[bolo78910]

Thanks , heading back to the boat after work today, I don't even know where to start, only thing leave it to put a new distributor cap, I will take a look on the the ignition module to see if someone install the wrong one.