OMC Cobra gear ratio question.....

[wilkboater]

I'm working on an 88 Bayliner, 5.0 OMC Cobra drive, that has bad upper gears. If I'm correct in my research, it is 21:17 ratio. I may have an opportunity to buy an OMC Cobra from an 89 model with a 5.7 engine. I think that ratio will be 21:16. Won't that lower my engine rpm at a given speed? I know I won't have peak performance, but I'm just trying to get the family boat back on the water for tubing and cruising. I'm not sure of these ratios, I'm just piecing these together from different information sources. Can anyone help me clear this up, or offer advice?

Thanks in advance,
Jeff

 

[wilkboater]

Re: OMC Cobra gear ratio question.....

Btt

 

[HT32BSX115]

Re: OMC Cobra gear ratio question.....

Howdy,

You're probably ok using that drive.

You might need to change the prop pitch like from a 19p to a 17p if the WOT RPM is low, but it should work ok.