New lower Unit with diff gear ratio, what prop now?

[Grassi25]

I have a 07 etec 225 HO. The lower unit went out, and my mechanic said they no longer make that gear case due to failures and the only lower unit I could get is now a different gear ratio. So now the same prop a 26 pitch only pushes 5000 rpms and lost a good 8-10 mph. Does anyone know which prop I should switch to. And will I still get the same performance as I used to?

 

[Maclin]

Can you get details from the mechanic regarding what ratio it has now? Did the shop not give any advice? Might could ask them what others have done when this swap was made since they know of multiple failures like this.

 

[steelespike]

I did a search on the net for 225 ho etec gear case failure. Several titles came up.They talked of L1 and M2 gear cases.
2013.

 

[SkiDad]

I'm guessing your old was 1.85/1.86 and new 1.75. Then 24 pitch would get you back to your old Rpms. Im guessing you were turning 5300 before. A 23 might also be a good choice. What was your old rpm ?

 

[Texasmark]

go-fast.com has a prop slip calculator. Plug in your current numbers (gear ratio is just the number, like 2 or 1.76, not 2:1 type thing) and solve for whatever you want....leave that box blank. After you get your answer, leave that box blank again, but go to the gear ratio box and change the number. Then you will see what you can reasonably expect. If you don't like the number, like rpm is too high or low, change the pitch of the prop and run it again and again till you get the right number then buy that pitched prop of the same type you have from the same mfgr. to minimize your variances as all props of the same pitch are not built alike and perform differently.