Cobra outdrives 23 vs 30

"I'm looking to install a

"I'm looking to install a 1989 2.3 cobra outdrive on my 1988 cobra 3.0.

Are the gear ratios the same and if not, will changing propellers get me close to the same performance?"

"2.3 used a 2.0:1 overall gear

"2.3 used a 2.0:1 overall gear ratio
1988 3.0 used a 1.71:1 overall.

depends what propeller you have now as to whether a prop swap will get you in range.
What prop are you running, and what is your WOT rpm?

An 89 or newer 3.0 drive is the one to look for as they had the larger 15 spline propshaft and heavier lower unit. Overall ratio for 89 and later 3.0 was 1.86 which was in the middle and correctable either way usually with propping"

"13 1/4" X 15P prop. WOT 4

"13 1/4" X 15P prop. WOT 4000 - 4300~ rpm.

I've already bought the 2.3 outdrive. Too good to pass up. If it won't work, the lower gears are the same as my 1988 3.0.

If I can re-prop, I won't have to mess around and split the units."

"Good show - If you are runni

"Good show - If you are running a 15P now, you should be able to compensate with prop swap no problem.

I would have been concerned only if you had a light weight boat and were currently running a 21 or 23P, but you must have a 19 footer or something heavier...and the 2.3 drive might actually be better suited. You will definitely need more pitch though.
I would try a 19P for starters."

"Thanks for the info Hy Stat.

"Thanks for the info Hy Stat.

The boat is a 1988 Glastron CX-19 (19 footer with cuddy)and she's a heavy beast.

Another method to my madness:

I want to be able to do some trolling for fish in the spring and fall. Right now my setup is too fast for trolling and if I prop down anymore I won't be able to get to the other end of the lake before it freezes over!

I'm hoping the 2.3 drive will allow me to prop nicely for trolling at 1000~ rpm in the spring and fall and re-prop for fun in the summer months.

Again, thank you very much!!"

"Scott,

Keep in mind, the

"Scott,

Keep in mind, the 2.3 was meant to spin 5600 RPMs and for that reason, OMC used a different, although similar, water pump in the outdrive. I don't see your 3.0 holding together at 5600, so you might want to consider putting the 3.0 pump back into the 2.3 upper. Just a thought.

Rick"

"I never thought of that altho

"I never thought of that although I have read that the pumps are different. (lower profile on the 2.3 impeller)

If the 3.0 pump assembly bolts up to the 2.3, I will definitely change it out.

Thanks Rick!!"

Bought various used props on e

Bought various used props on ebay to try out on the 2.3 drive including a couple of stainless steel props.

The SS props are much much} heavier (weight) than the aluminum.

I'm concerned to even try them out.

Is this going to wear out the drive quicker??

"No...you'll be fine but i

"No...you'll be fine but if you put too big a pitch on there you will be at the other end of the lake before you hit WOT "