Bad top end
 

Hi, today i tested my boat cobalt model 272 year 1994 with bravo 3 ratio 1,8 and mercruiser engine 454 marck 4 cyclone 400 HP -- SS pich 22, and i can not belive is take only top speed 45 milesx h at 4800 rpm full trotle wiith only few trim up, 3 persons, in good sea water conditions fuel only 1/4 .

The mercruiser said this engine the wot it is 4800-5200.... The problem is i can not go to picher up aprox 300 rpm in bravo 3.......on the contrary i have to go to 20 pich it is crazy, i will lost top speed, in the test i feel the engine very strong Great,....i think the performance will be around 50-55 miles.

Note
The gauges are new farias
4500 lbs- 27 '
The tune up was perfect

Please any help


Thanks in advance


Erick

It is unlikely your motor is making 400 hp. Even if it was with the size of the boat your performance is about where I'd expect it to be. Verify the speed with a GPS as your current prop slip is a little high for a Bravo III drive.

Hi trash, thanks for your comments, i will check with a gps next sunday, about bravo 3 mercruiser said it is ok up 400Hp, ,
PLease what do you think the engine can not making the 400 hp? I relly like to know your opinion.....thanks again

Erick

Did you keep trimming up until you stopped gaining rpms and speed????

Bottom paint, if it has it, will also slow you down up to 5mph.

Hi Griff, The answer for your question is yes.... What is the correct procedure to do the trim aceleration to take the max top speed? I really want to learn....

The botton is painted with trinidad paint antifouling, but i keep clean all time

Thanks in advance for your comments

Regards

Erick

..

Just trim up until you stop gaining any mph. Once you stop gaining speed, then stop trimming up. Make sure trim tabs are all the way up also if you have them.
The Bravo 3 is not a drive made for top speed either. Its more for getting on plain quickly and is used on heavier boats.

Griff, thanks for your comments .... Now i am clear.....erick

I'm not sure your boat only ways 4500lbs. I had a 03 Rinker Captiva 232 cuddy and it weighed dry at 4800. I too had the bravo 3 drive, but on a 350 MAG MPI putting out 300hp I got top end 52 and some change. I had it trimmed as high as it would trim. Not sure what my rpms were or what pitch my blades were. I'm sure with some digging I could find out.