Reply
 
Thread Tools Search this Thread
 
Old 14 January 2014, 17:03   #11
RIBnet supporter
 
Chris Caton's Avatar
 
Country: UK - England
Town: Wirral & Caernarfon
Boat name: That's Enuff
Make: Revenger & Avon SR4
Length: 7m +
Engine: Honda 150HP & 50HP
Join Date: Jul 2011
Posts: 4,199
buy a bigger engine Gareth, it's the best n only option
__________________
Chris Caton is offline   Reply With Quote
Old 15 January 2014, 13:43   #12
Member
 
Country: UK - England
Boat name: Carpe Diem
Make: Ribeye 650S
Length: 5m +
Engine: Yamaha F150
Join Date: Oct 2012
Posts: 547
Yeah, more power

Quote:
Originally Posted by PeterM View Post
I'm going to fiddle with my f50 after watching that ! :-)
Go for it Peter, there was also a forum something like the hull truth where loads of people had done it and were all reporting engine performance improvements

Let us know how you get on Peter
__________________

__________________
whackywoody is offline   Reply With Quote
Old 15 January 2014, 15:04   #13
Member
 
Country: UK - England
Town: Dorset & Hants
Boat name: Streaker/Orange
Make: Avon/Ribcraft
Length: 4m +
Engine: 50Yam/25 Mariner
Join Date: Apr 2007
Posts: 5,551
Look what I just took out....
Attached Thumbnails
Click image for larger version

Name:	ForumRunner_20140115_200355.jpg
Views:	149
Size:	20.5 KB
ID:	89251  
__________________
PeterM is offline   Reply With Quote
Old 15 January 2014, 15:06   #14
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
Quote:
Originally Posted by whackywoody View Post
Thanks everyone for their responses as you have confirmed my suspicions

I have seen another article about removing restrictor plates on yamaha 4 stroke engines to allow more fuel and air to the engine to produce more power. See youtube link below but must admit narrator is pretty boring



Does this look like a feasible option to increase power?

I'm pretty sure somebody is gonna tell me to buy a bigger engine as it will be the only solution
Restriction plate, different carb, tweak to the spark advance. Bottom line is outboards sell in relatively small volume to their development costs. So if you can use one set of expensive castings on two or three products...

If your engine has a higher horsepower identical weight sibling chances are you will be able to up the gee gees.

If its the top hp of a group of similarly lardy lumps you are into bespoke re-tune territory to get more out.
__________________
9D280 is offline   Reply With Quote
Old 15 January 2014, 15:21   #15
Member
 
Country: UK - England
Town: Dorset & Hants
Boat name: Streaker/Orange
Make: Avon/Ribcraft
Length: 4m +
Engine: 50Yam/25 Mariner
Join Date: Apr 2007
Posts: 5,551
The 50 efi/injected shares block with the 60 & 70.

Makes sense that with the ecu relearning the flows out will allow more air in...

The most simple way to increase horses is to let it breath easier....

What's the worst that can happen!
__________________
PeterM is offline   Reply With Quote
Old 15 January 2014, 15:42   #16
Member
 
Trimix's Avatar
 
Country: UK - England
Boat name: Hysucat
Make: Hysucat
Length: 8m +
Engine: Twin Suzuki 175's
MMSI: 235102645
Join Date: Jun 2013
Posts: 861
RIBase
If you make it breath in the fuel/air more you will have to eliminate any exhaust restrictions. Or there will be an imbalance, resulting in heat/inefficeny/unburnt fuel/etc.

What flows in must be burned efficently, then removed from the exhaust.

You wont get much by just unrestricting the inflow. You will have to do some headwork (gasflow/porting) alter the ignition curve and unrestrict the exhaust.

Its all a balance and mostly limited by gas laws, followed by ignition and temperature.

If it was tuned to run with the restictor in place it cant be in tune without it - can it ?
__________________
Trimix is offline   Reply With Quote
Old 15 January 2014, 15:46   #17
Member
 
Country: UK - England
Town: Dorset & Hants
Boat name: Streaker/Orange
Make: Avon/Ribcraft
Length: 4m +
Engine: 50Yam/25 Mariner
Join Date: Apr 2007
Posts: 5,551
I appreciate the limits of exhaust and porting etc.

The ecu will get input about airflow and injector timings etc and ignition timings and adjust as much as it can?
__________________
PeterM is offline   Reply With Quote
Old 15 January 2014, 15:48   #18
Member
 
A1an's Avatar
 
Country: UK - Scotland
Town: Fort William
Make: Humber Destroyer
Length: 5m +
Engine: Yamaha F80
Join Date: Mar 2012
Posts: 2,239
RIBase
I'd be interested in the AFR reading.


My worry would be that the ECU can't actually adjust the fuel relative to the extra air thus leaning it out. (Which is dangerous)


I've spent years trying to tune cars, trying to squeeze that little bit more power out of them and I have to say the majority of modification do nowt. The only proper way to get extra power is to rewrite the fuel mapping.

The "placebo effect" is an amazing thing.
__________________
There is a place on this planet for all of Gods creatures.........right next to my tatties and gravy.
A1an is offline   Reply With Quote
Old 15 January 2014, 15:49   #19
Member
 
Country: UK - England
Boat name: Carpe Diem
Make: Ribeye 650S
Length: 5m +
Engine: Yamaha F150
Join Date: Oct 2012
Posts: 547
Quote:
Originally Posted by PeterM View Post
Look what I just took out....
Crikey you don't hang about............. When is the performance test to prove it works?

Don't blame me if it breaks down
__________________
whackywoody is offline   Reply With Quote
Old 15 January 2014, 15:53   #20
Member
 
Country: UK - England
Town: Dorset & Hants
Boat name: Streaker/Orange
Make: Avon/Ribcraft
Length: 4m +
Engine: 50Yam/25 Mariner
Join Date: Apr 2007
Posts: 5,551
Well it'll be lighter without the washer..so the laws of physics tell me it must be faster! (Probably by a very very very very small but calculateable amount....

Placebo? Of course it's faster! It MUST be B-)
__________________

__________________
PeterM 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 19:12.


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