Reply
 
Thread Tools Search this Thread
 
Old 08 August 2009, 17:13   #21
JSP
Member
 
Country: UK - England
Town: Southport
Boat name: Qudos
Make: 5.4 Searider
Length: 5m +
Engine: Yam 115 V4
MMSI: 235068784
Join Date: Sep 2008
Posts: 3,930
There's a bloke up here with an evinrude, he can use it fine around the dock but as soon as he goes out the dock gate it losses all power. Comes back in and the power comes back. So tries again and as soon as he leaves the dock gates, no power. This is keeping it at the same revs all the time!
__________________
JSP is offline   Reply With Quote
Old 08 August 2009, 17:45   #22
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
Quote:
Originally Posted by JSP View Post
There's a bloke up here with an evinrude, he can use it fine around the dock but as soon as he goes out the dock gate it losses all power. Comes back in and the power comes back. So tries again and as soon as he leaves the dock gates, no power. This is keeping it at the same revs all the time!
Simple ! Its one of 2 things , fuel or electrics - I dont charge for these pearls of wisdom !

does he keep running it when its not right ? if he does surely its just likely to do long term harm .

Any one on here running with long term problems .............?
__________________
PeterM is offline   Reply With Quote
Old 08 August 2009, 17:52   #23
JSP
Member
 
Country: UK - England
Town: Southport
Boat name: Qudos
Make: 5.4 Searider
Length: 5m +
Engine: Yam 115 V4
MMSI: 235068784
Join Date: Sep 2008
Posts: 3,930
Quote:
Originally Posted by Blackroady View Post
Simple ! Its one of 2 things , fuel or electrics - I dont charge for these pearls of wisdom !

does he keep running it when its not right ? if he does surely its just likely to do long term harm .

Any one on here running with long term problems .............?
He's one that everyone just leaves well alone if you get what I mean.

Long term problems...me?.....naaaa
__________________
JSP is offline   Reply With Quote
Old 08 August 2009, 21:11   #24
Member
 
Country: Ireland
Boat name: Bullfrog
Make: DSB - Osprey
Length: 5m +
Engine: Outboard, Petrol, 55
Join Date: Aug 2008
Posts: 35
Went out today and checked all the things we earlier discussed - Fuel lines, breather, priming bulb - all looks good.
Now this may be irrelevant but I'm not sure - It only occurred to me an hour ago:- Everytime this happens I've went through the same procedure, either just filled the fuel tank or went out with a full tank of juice. After around the hour, the tank falls to around the 3/4 mark ish - then she cuts back to 4500rpm.
Or is this just coincidence??
__________________
Steve.N is offline   Reply With Quote
Old 08 August 2009, 21:20   #25
Member
 
Country: UK - England
Town: Hamble
Boat name: Worth the wait
Make: Parker
Length: 7m +
Engine: Outboard
Join Date: Apr 2008
Posts: 1,446
From your description, that does sound like the tank cannot breath. The loss of about quarter of a tank would be about right for a strong vacuum to develope and therefore restrict the flow to the engine. Check out your breather tube and if unsure just replace it as it may have collapsed internally.
__________________
Steve_B is offline   Reply With Quote
Old 10 August 2009, 00:24   #26
Member
 
Country: Ireland
Boat name: Bullfrog
Make: DSB - Osprey
Length: 5m +
Engine: Outboard, Petrol, 55
Join Date: Aug 2008
Posts: 35
Quote:
Originally Posted by 250kts View Post
From your description, that does sound like the tank cannot breath. The loss of about quarter of a tank would be about right for a strong vacuum to develope and therefore restrict the flow to the engine. Check out your breather tube and if unsure just replace it as it may have collapsed internally.

Good call 250kts - The breather was sitting in a puddle and covered in dirt. I discovered it wrapped in a corner up behind the fuel tank. I removed it and blew through - there definitely was something in it so I re-routed it neatly out of the way.
After reading the posts the other day I went and bought fresh fuel line and primer bulb - So I changed it all today as well.
The primer bulb now goes rock hard when pressurized and is still pretty hard with the engine running.
Will take her out on Wednesday for a test spin - Fingers Crossed
__________________
Steve.N is offline   Reply With Quote
Old 13 August 2009, 10:00   #27
Member
 
Country: Ireland
Boat name: Bullfrog
Make: DSB - Osprey
Length: 5m +
Engine: Outboard, Petrol, 55
Join Date: Aug 2008
Posts: 35
This Saga Continues!!!!

Took the boat out yesterday - The engine still wont rev above 4,500rpm!!!!
The difference this time is that usually the motor performs well for an hour or so then cuts back - But this time she was under-performing from the onset. She was ticking over lovely and sounded well as we cruised out of the harbour, but when I went to power up she would only rev to 4,500RPM - She actually sounded choked!!!
It's definitely not the fuel supply as my previous post stated - new fuel hoses & Primer bulb (The bulb was rock hard when engine running!)
I then changed over to my spare fuel tank (with it own new hoses, primer bulb & fuel connection) - Still the same lack of power.

Where do I go from Here - HELP!!! I'm fast getting to wits end!
__________________
Steve.N is offline   Reply With Quote
Old 13 August 2009, 23:10   #28
Member
 
Country: UK - England
Town: Fareham
Boat name: Nectar
Make: Robinson Marine
Length: 6m +
Engine: Yamaha 2/
MMSI: 235053259
Join Date: May 2009
Posts: 62
This may sound really silly Steve but I once installed the new fuel line the wrong way round and had identical symptoms to yours, check the arrow on the primer bulb. It cost me a trip to the local dealer to realise what a prat I was!!
__________________
hatt11 is offline   Reply With Quote
Old 14 August 2009, 09:51   #29
Member
 
Country: Ireland
Boat name: Bullfrog
Make: DSB - Osprey
Length: 5m +
Engine: Outboard, Petrol, 55
Join Date: Aug 2008
Posts: 35
Quote:
Originally Posted by hatt11 View Post
This may sound really silly Steve but I once installed the new fuel line the wrong way round and had identical symptoms to yours, check the arrow on the primer bulb. It cost me a trip to the local dealer to realise what a prat I was!!



Hi, hatt11 - Just checked - Bulb correct way around. you're right, sometimes these problems are solved by something silly being wrong, if only this problem was as simple!
Next port of call - fuel pump - Carbs then Throttle Sensor.
Has any of you guys got any advice????


Steve.
__________________
Steve.N is offline   Reply With Quote
Old 14 August 2009, 15:50   #30
Member
 
jambo's Avatar
 
Country: UK - Scotland
Town: Girvan & Tayvallich
Boat name: Breawatch
Make: Ribcraft
Length: 5m +
Engine: Mercury 150 F/stroke
MMSI: ex directory!!
Join Date: Sep 2008
Posts: 6,203
RIBase
Hi Steve I had same or similar last month on my 150 Mariner 2st. I renewed all the filters , plugs, checked the primer and stripped the carbs and flushed them!! But it turned out to be the diaphragm in the pump. Have you renewed it?

J
__________________
jambo
'Carpe Diem'
Member of the ebay Blue RIB cover club
Member of SABS ( Scottish West Division)
jambo is offline   Reply With Quote
Old 14 August 2009, 19:18   #31
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Quote:
Originally Posted by JSP View Post
There's a bloke up here with an evinrude, he can use it fine around the dock but as soon as he goes out the dock gate it losses all power. Comes back in and the power comes back. So tries again and as soon as he leaves the dock gates, no power. This is keeping it at the same revs all the time!
Is there water beyond the gate?

Sorry; had to ask...

jky
__________________
jyasaki is offline   Reply With Quote
Old 14 August 2009, 19:24   #32
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Quote:
Originally Posted by Steve.N View Post
Hi, hatt11 - Just checked - Bulb correct way around. you're right, sometimes these problems are solved by something silly being wrong, if only this problem was as simple!
Next port of call - fuel pump - Carbs then Throttle Sensor.
Has any of you guys got any advice????

Steve.
Steve;

Can you run with a small tank of fuel, and mount it on top of the engine on a short piece of fuel line? The siphon from that configuration should supply fuel even with a fuel pump not working at 100%.

And, pumping the bulb with your current setup should overcome any poorly performing fuel pump as well.

Do you have an in-line fuel filter (Racor type) installed? Is it a new element? How about any in-line filters under the cowl?

jky
__________________
jyasaki is offline   Reply With Quote
Old 14 August 2009, 20:39   #33
Member
 
jambo's Avatar
 
Country: UK - Scotland
Town: Girvan & Tayvallich
Boat name: Breawatch
Make: Ribcraft
Length: 5m +
Engine: Mercury 150 F/stroke
MMSI: ex directory!!
Join Date: Sep 2008
Posts: 6,203
RIBase
Steve also remember there is a tiny filter at the bottom of the fuel line into the carbs check that as well.

J
__________________
jambo
'Carpe Diem'
Member of the ebay Blue RIB cover club
Member of SABS ( Scottish West Division)
jambo is offline   Reply With Quote
Old 15 August 2009, 23:46   #34
Member
 
Country: Ireland
Boat name: Bullfrog
Make: DSB - Osprey
Length: 5m +
Engine: Outboard, Petrol, 55
Join Date: Aug 2008
Posts: 35
Hi guys,

Thanks for the responses - I was planning on checking the fuel pump yesterday but the weather prevented that!!
Will remove the fuel pump tomorrow!

jky - I have a inline water/fuel separator filter installed, is that what you mean??
I have replaced the small fuel filter that is after the pump. Is that the one you mean Jambo?
__________________
Steve.N is offline   Reply With Quote
Old 23 August 2009, 10:08   #35
Member
 
Country: Ireland
Boat name: Bullfrog
Make: DSB - Osprey
Length: 5m +
Engine: Outboard, Petrol, 55
Join Date: Aug 2008
Posts: 35
Just to finish this thread off, After checking the fuel pump and throttle position sensor and finding nothing wrong I pulled the carbs off.
Gave them a complete strip down and found sand in one and white lumpy stuff in another. Also found my main jets were blocked on the top two!
After a good cleaning and a few scuffed knuckles had her out on the water for a good 3hr spin on Thurs - no probs - YEEHAAA!!!!
At last she ticks over and pulls as she should!

Thanks everyone for their advice - I got a great masterclass on outboard maintenance!
__________________
Steve.N is offline   Reply With Quote
Old 23 August 2009, 23:11   #36
Member
 
jambo's Avatar
 
Country: UK - Scotland
Town: Girvan & Tayvallich
Boat name: Breawatch
Make: Ribcraft
Length: 5m +
Engine: Mercury 150 F/stroke
MMSI: ex directory!!
Join Date: Sep 2008
Posts: 6,203
RIBase
Glad you are back on the water Steve!
Cheers
J
__________________
jambo
'Carpe Diem'
Member of the ebay Blue RIB cover club
Member of SABS ( Scottish West Division)
jambo is offline   Reply With Quote
Reply


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




All times are GMT. The time now is 07:03.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.