Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   Drives and Lower Units (https://www.offshoreonly.com/forums/drives-lower-units-217/)
-   -   Imco question on planing (https://www.offshoreonly.com/forums/drives-lower-units/371705-imco-question-planing.html)

Pulse74 05-23-2021 03:34 PM

Imco question on planing
 
I just swapped a bravo xr lower to a imco sc lower. Already had a scx upper. Only issue I’m having is getting up on plane. The xr lower jumped on plane no issues. The imco rolls up to 3k no issue then feels like the prop slips and have a heck of a time getting to roll over. Even with dropping tabs. Anyone else experience this?

F-2 Speedy 05-23-2021 03:54 PM

are the lowers the same length ? drive shower ?

Pulse74 05-23-2021 03:56 PM


Originally Posted by F-2 Speedy (Post 4790780)
are the lowers the same length ? drive shower ?


everything the same. Standard length on both. I assume standard is the same length. Prop depth is the same at 4.5 at neutral

F-2 Speedy 05-23-2021 03:59 PM

did you install a drive shower ?

Pulse74 05-23-2021 04:00 PM


Originally Posted by F-2 Speedy (Post 4790782)
did you install a drive shower ?

no, just the built in shower on the scx

F-2 Speedy 05-23-2021 04:18 PM


Originally Posted by Pulse74 (Post 4790783)
no, just the built in shower on the scx

seems odd, same prop and shaft depth and blows out, Im going from xr's to -1 imco lowers haven't ran the boat yet hope I dont have issues

Pulse74 05-23-2021 04:25 PM


Originally Posted by F-2 Speedy (Post 4790785)
seems odd, same prop and shaft depth and blows out, Im going from xr's to -1 imco lowers haven't ran the boat yet hope I dont have issues


yeah so far I’m not sure about the swap. Boat also now leans to starboard on cruising. Tab doesn’t do much for correcting.

SB 05-23-2021 04:28 PM

Cavitation plate same size ?

Pulse74 05-23-2021 04:36 PM


Originally Posted by SB (Post 4790787)
Cavitation plate same size ?

yep didn’t do anything to the upper

F-2 Speedy 05-23-2021 04:51 PM


Originally Posted by Pulse74 (Post 4790788)
yep didn’t do anything to the upper

can you post a pic of the drive

Pulse74 05-23-2021 04:52 PM


Originally Posted by F-2 Speedy (Post 4790791)
can you post a pic of the drive

https://cimg1.ibsrv.net/gimg/www.off...d3c56aedec.jpg

F-2 Speedy 05-23-2021 04:59 PM

is there anything stamped in the very front of the lower where it bolts up

Pulse74 05-23-2021 05:08 PM


Originally Posted by F-2 Speedy (Post 4790796)
is there anything stamped in the very front of the lower where it bolts up

https://cimg4.ibsrv.net/gimg/www.off...0e08e4ddbd.jpg

F-2 Speedy 05-23-2021 05:14 PM

Is that stamp at the rear , Id say standard, did the lower come with that stud and and nylon nut ?

Pulse74 05-23-2021 05:17 PM

Couldn’t say. I had a reputable shop (MDG Performance) install it. Went in for a rebuild of my xr lower and it was trashed. Case couldn’t be salvaged, so we got the imco.

F-2 Speedy 05-23-2021 05:24 PM

My drive guy told me to put an allen head bolt in the rear spot so it would not protrude below the drive case because it could cause cavitation, I would pull the stud and nut and put an allen head bolt in its place and go test it, even Imco's installation guide there cavi plate for the drive shower said point the bolts upward to prevent cavitaion

Pulse74 05-23-2021 05:58 PM

That’s a possibility. Cause even when I get on plane it still doesn’t feel right. Feels like the prop is slipping. I even checked to see if the prop was spinning. It feels that loose.

Pulse74 05-23-2021 05:59 PM

So I guess I’d have to drop the lower to change the stud

F-2 Speedy 05-23-2021 07:32 PM


Originally Posted by Pulse74 (Post 4790805)
So I guess I’d have to drop the lower to change the stud

No, remove the nut and and take a pair of pliers or double nut the stud and remove the it,

540Fever 02-16-2023 06:57 PM

Searching some threads here with IMCO lowers... Just curious if this was resolved or not? Not necessarily having issues with plaining, but prop slip.

One of the things mentioned was the bolt on the back securing the upper/lower units. I have the same setup with the bolt and a nut on it. Will be worth trying an allen head bolt.

I do have a drive shower and mine is on the left / port side with a left-hand prop. I'm going to pull it this spring and do some testing without the shower pickup.

Any other considerations with the IMCO lowers? Mines just a standard height -0.

Thanks


All times are GMT -5. The time now is 06:38 AM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.