Reply
 
Thread Tools Search this Thread
 
Old 20 April 2014, 09:13   #1
Member
 
Country: UK - Scotland
Town: Glasgow
Boat name: Enigma
Make: Osprey
Length: 5m +
Engine: Outboard 70hp
Join Date: Mar 2014
Posts: 20
Evinrude 70hp problem

Hi all, firstly I will apologise for my total lack of understanding, but this is my first rhib and outboard so I'm on a learning curve.
Right, my problem, ran the engine yesterday on Loch Fyne and at first it was running sweet, we did a run out and back opened it up to see what she would do, 25 knots and all was great, on our second run out we picked up a fishing line around the prop, jumped in and got it all off. After that we set off again and all was well after 10 mins of running we arrived close to a dive site I slowed down, we decided to go to the next site, when I opened the throttle all I got was 7 knots. I put her into neutral set off again and I got power, then it dropped again I found that by moving the throttle leaver you could feel the engine bite and then it was of at full revs.
Engine idles fine, selects gears fwd & rev, no miss fires just this loss of power.
I have the workshop manual but I'm looking for some info in simple terms for a simple newbie!
Thanks for any help.
__________________

__________________
Historicalgasman is offline   Reply With Quote
Old 20 April 2014, 09:50   #2
Member
 
Landlockedpirate's Avatar
 
Country: UK - England
Town: St Helens
Boat name: Wine Down
Make: Maxum
Length: 8m +
Engine: Inboard
Join Date: Apr 2012
Posts: 934
Its possible that you have spun the bush in the prop, this happens naturally over time but the line round the hub could have accelerated the damage.

You can send the prop off to Steel Developments to be rebushed.
__________________

__________________
Landlockedpirate is offline   Reply With Quote
Old 20 April 2014, 19:38   #3
Member
 
Country: UK - Scotland
Town: Glasgow
Boat name: Enigma
Make: Osprey
Length: 5m +
Engine: Outboard 70hp
Join Date: Mar 2014
Posts: 20
Thanks, when I take the prop off, how can I tell if that is the case?
__________________
Historicalgasman is offline   Reply With Quote
Old 21 April 2014, 04:05   #4
RIBnet admin team
 
Poly's Avatar
 
Country: UK - Scotland
Boat name: imposter
Make: FunYak
Length: 3m +
Engine: 2 stroke YAM 20 HP
MMSI: 235089819
Join Date: Sep 2005
Posts: 10,112
You want to put a mark/line across the radius of the prop so that the centre and outside are both covered (e.g. use indellible pen or tipex depending on colour of prop) then take boat for a spin to get the symptoms you describe - afterwards if the mark is no longer one continuous line it has been slipping.

There is a prop repair place in Clydebank which will save you postage if you are passing.
__________________
Poly is offline   Reply With Quote
Old 21 April 2014, 04:16   #5
Member
 
Country: UK - Scotland
Town: Glasgow
Boat name: Enigma
Make: Osprey
Length: 5m +
Engine: Outboard 70hp
Join Date: Mar 2014
Posts: 20
I work in Clydebank, I take it you mean I mark the nut in the centre and the rim of the prop and if the 2 don't line up off to Clydebank with the prop. Do you have the name of the company?
__________________
Historicalgasman is offline   Reply With Quote
Old 21 April 2014, 04:20   #6
Member
 
Country: UK - Scotland
Town: Glasgow
Boat name: Enigma
Make: Osprey
Length: 5m +
Engine: Outboard 70hp
Join Date: Mar 2014
Posts: 20
Reading the manual, it describes similar symptoms and says its the fuel pump, what do you guys think?
__________________
Historicalgasman is offline   Reply With Quote
Old 21 April 2014, 05:24   #7
Member
 
Landlockedpirate's Avatar
 
Country: UK - England
Town: St Helens
Boat name: Wine Down
Make: Maxum
Length: 8m +
Engine: Inboard
Join Date: Apr 2012
Posts: 934
Is the loss of power a loss in forward motion with revs still on the max or a loss of revs ?(i.e. you floor the accerator and the engine doesnt rev)
__________________
Landlockedpirate is offline   Reply With Quote
Old 21 April 2014, 05:33   #8
Member
 
Country: UK - Scotland
Town: Glasgow
Boat name: Enigma
Make: Osprey
Length: 5m +
Engine: Outboard 70hp
Join Date: Mar 2014
Posts: 20
Quote:
Originally Posted by Landlockedpirate View Post
Is the loss of power a loss in forward motion with revs still on the max or a loss of revs ?(i.e. you floor the accerator and the engine doesnt rev)
I havent got the rev guage connected yet, but the engine wasnt at full revs even with the throttle fully forward, but it would then jump to life with a wiggle of the throttle and you could feel the engine bite, on the way back in it was surging itself going from 7 knots up to about 16 without moving the throttle.

By the way I'm from St Helens!
__________________
Historicalgasman is offline   Reply With Quote
Old 21 April 2014, 05:37   #9
RIBnet supporter
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 7,579
RIBase
Quote:
Originally Posted by Historicalgasman View Post
By the way I'm from St Helens!
Ahh, that explains it

PS it doesn't sound like the prop is slipping, what model of Evinrude is it? Etec, FICHT (don't think they made a 70hp FICHT but I could be wrong)
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4: See rule#5
Pikey Dave is offline   Reply With Quote
Old 21 April 2014, 05:41   #10
Member
 
Country: UK - Scotland
Town: Glasgow
Boat name: Enigma
Make: Osprey
Length: 5m +
Engine: Outboard 70hp
Join Date: Mar 2014
Posts: 20
Quote:
Originally Posted by Pikey Dave View Post
Ahh, that explains it
Steady now, at this Christian festival we don't want to ignite the Lancashire, Yarkshire battle.
__________________

__________________
Historicalgasman 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 06:48.


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