Reply
 
Thread Tools Search this Thread
 
Old 21 June 2011, 17:08   #1
Member
 
Country: UK - England
Town: Orpington
Make: Seapro 340HD
Length: 3m +
Engine: Tohatsu 9.8HP
Join Date: May 2011
Posts: 40
Tuning a Mariner 2005 50HP EFI to a 60HP

Hi Guys,

Is it possible to chip or tune a Mariner 50HP EFI 4 stroke to a 60HP and if so what is involved. I'm sorry if it's a silly question, but I read somewhere that people were doing it.

Can it be done by a marine engineer and is it something he would do?

If it can be carried out. Could it cause any damage to the engine?


Kind regards

Popeye
__________________

__________________
Popeye1 is offline   Reply With Quote
Old 22 June 2011, 05:38   #2
Member
 
Country: UK - Wales
Town: West Wales
Make: Vipermax 5.8, SR4.7
Length: 5m +
Engine: 150 Opti, F50EFi
Join Date: Sep 2005
Posts: 6,298
Different ECU and the 50hp has an air restrictor in the inlet tract, which needs to be removed.
__________________

__________________
Downhilldai is offline   Reply With Quote
Old 26 June 2011, 05:30   #3
Member
 
Country: UK - England
Town: Orpington
Make: Seapro 340HD
Length: 3m +
Engine: Tohatsu 9.8HP
Join Date: May 2011
Posts: 40
Quote:
Originally Posted by Downhilldai View Post
Different ECU and the 50hp has an air restrictor in the inlet tract, which needs to be removed.
Downhilldai,

So it can be done then, if I change the ECU unit and remove the restrictor in the inlet tract.

Would I then need to change the prop? for an increase in 10HP of power, or could I get away with keeping the same prop.

Thanks

Popeye
__________________
Popeye1 is offline   Reply With Quote
Old 26 June 2011, 17:40   #4
Member
 
Country: UK - England
Town: Orpington
Make: Seapro 340HD
Length: 3m +
Engine: Tohatsu 9.8HP
Join Date: May 2011
Posts: 40
Quote:
Originally Posted by Popeye1 View Post
Downhilldai,

So it can be done then, if I change the ECU unit and remove the restrictor in the inlet tract.

Would I then need to change the prop? for an increase in 10HP of power, or could I get away with keeping the same prop.

Thanks

Popeye

Hi,

I would appreciate if someone would be kind enough to confirm the above question.

I know it's not exciting, but your help would be much appreciated.

Thanks

Popeye
__________________
Popeye1 is offline   Reply With Quote
Old 26 June 2011, 18:42   #5
Member
 
Country: UK - Wales
Town: West Wales
Make: Vipermax 5.8, SR4.7
Length: 5m +
Engine: 150 Opti, F50EFi
Join Date: Sep 2005
Posts: 6,298
That'll do it. With 20% more hp, you may over-rev the motor with the prop you currently use, or you may notice very little difference. What rpm are you hitting at full pelt now?
__________________
Downhilldai is offline   Reply With Quote
Old 27 June 2011, 05:17   #6
Member
 
Country: UK - Scotland
Boat name: Wildheart
Make: Humber/Delta Seasafe
Length: 5m +
Engine: Merc 60 Clamshell
MMSI: 235068449
Join Date: Apr 2007
Posts: 4,610
Chill... On a sunny Sunday afternoon there's a high chance some of us might be out burning fuel!

Prop wise the only way you'll find out is to go out & open the throttle. I guess from your info on the left you may have just bought the boat? If it's a nice lightweight hull, chances are you will need to up - pitch. If however you are going to have 3/4 ton of dive kit aboard that the previous owner dinlt carry, the extra Hp might be the difference between actually hitting max RPM or not.

Classic example, I got an engine off the back of a cabin cruiser. On the first outing I chickened out at 6600 at about 3/4 throttle and promptly bought a far bigger pitched prop. If it's a secondhand boat / engine chances are you'll have a different setup, regardless of the 20% extra power!

Bottom line is a test is the only way to find out. Worst case you just have to be mindful of the revs for the first outing.
__________________
9D280 is offline   Reply With Quote
Old 28 June 2011, 18:52   #7
Member
 
Country: UK - England
Town: Orpington
Make: Seapro 340HD
Length: 3m +
Engine: Tohatsu 9.8HP
Join Date: May 2011
Posts: 40
Quote:
Originally Posted by 9D280 View Post
Chill... On a sunny Sunday afternoon there's a high chance some of us might be out burning fuel!

Prop wise the only way you'll find out is to go out & open the throttle. I guess from your info on the left you may have just bought the boat? If it's a nice lightweight hull, chances are you will need to up - pitch. If however you are going to have 3/4 ton of dive kit aboard that the previous owner dinlt carry, the extra Hp might be the difference between actually hitting max RPM or not.

Classic example, I got an engine off the back of a cabin cruiser. On the first outing I chickened out at 6600 at about 3/4 throttle and promptly bought a far bigger pitched prop. If it's a secondhand boat / engine chances are you'll have a different setup, regardless of the 20% extra power!

Bottom line is a test is the only way to find out. Worst case you just have to be mindful of the revs for the first outing.



Thank you and everybody else for the replies.
__________________

__________________
Popeye1 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

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





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 20:44.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.