Thread Tools Display Modes
Old 06-10-2017, 12:04 AM   #1
Registered User
glen76's Avatar
Country: england
Location: southampton
Occupation: engineer
Interests: lots
Boat make: scorpion 8.1
Engines: 250HO
Cruising area: solent

Join Date: Mar 2004
Location: southampton
Posts: 1,347
Removing jack plate.

I have a long shaft etec on a 24.5” transom.

I was concerned about it being too high so instead of cutting transom down, I chucked the motor on a 5.5 cmc manual plate. The gearbox bullet runs level with transom and it runs pretty good on rev4 prop.

It annoys the hell out of me that the steering impacts the transom top when I tilt and I can’t go up more than 1/3. So now I’m trying to choose between cutting transom down. Adding moooore offset, or chucking it straight on transom, where I would have a good 2” of down movement available to me.

Question is will I lose speed removing my 5.5” setback? Currently 60mph and some discrepancies on rpm between crew but somewhere around 1000rpm to low.

Has anyone got direct comparison with or without setback?

glen76 is offline   Reply With Quote
Old 14-01-2018, 11:46 PM   #2
Registered User
Country: UK
Location: London
Occupation: Automotive Technician/consultant
Interests: Doing up my boat
Boat name: Jeepster
Boat make: Marina 16 G.T.
Engines: Suzuki DF50
Cruising area: Thames and the Solent

Join Date: Jan 2018
Location: London
Posts: 3
Hi Glen...The gearbox "bullet" should be below your transom...The general rule of thumb is that it is the anti-cavitation plate that should be level with the bottom of the transom for best performance. (although if you are already getting 60mph, I would leave it where it is!).
jeepster1 is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Powered by vBadvanced CMPS v3.2.3

All times are GMT +1. The time now is 06:33 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.