Reply
 
Thread Tools Search this Thread
 
Old 24 September 2011, 17:18   #1
Member
 
Country: UK - England
Town: Sussex
Make: RIBTEC 655
Length: 6m +
Engine: Yam 150
Join Date: Oct 2007
Posts: 1,157
Selva/Yamaha 50hp 4stroke conking out

Hi all,

I recently bought a 4.5m Valiant with a 5 year old 50hp 4 stroke Selva, re badged Yamaha, from a friend of mine, it had been sat in a river and had less than 20 hours use and as far as I can make out had never been opened up as the river has a 8 knot speed limit - I know what I was buying and aware of the history and it was serviced.

I had it serviced again locally and took it out today, I was having a problem with it dieing when I went to engage gear and at a low RPM and it did not sound healthy but when it I gave it some throttle it was fine, it seemed to clear itself so I headed out of Chichester to open it up (had arranged to meet a friend at West Pole just in case of problems).

It was running fine, though seemed a little underpowered for a 50hp on a boat that size, after about 10 mins the problem came back and it would not idle at all and it sounded terrible at low RPM so we towed it back into the harbour, where as before it would come back to life it remained sick every time I tried it, periodically on the trip back to the marina.

I have a warranty from the service and will take it back next week but would love to know what the problem could be.
__________________

__________________
thomas is offline   Reply With Quote
Old 25 September 2011, 06:47   #2
Member
 
Country: UK - England
Town: Bristol
Make: Ribcraft
Length: 5m +
Engine: Yamaha
Join Date: May 2006
Posts: 4,194
Water in float bowls of carbs (im guessing carbed model) !!
__________________

__________________
matt h is offline   Reply With Quote
Old 25 September 2011, 07:00   #3
Member
 
Country: UK - England
Town: southampton
Make: ribeye
Length: 6m +
Engine: 100
Join Date: Jul 2006
Posts: 194
You haven't used 5 year old fuel that came with the boat!
That's the only thing that may have been different after your mechanics service, as I assume he had it up and running to carry out his work!

Otherwise, it doesn't sound like much was carried out by the mechanic.
__________________
ribber is offline   Reply With Quote
Old 25 September 2011, 13:29   #4
Member
 
Country: UK - England
Town: Sussex
Make: RIBTEC 655
Length: 6m +
Engine: Yam 150
Join Date: Oct 2007
Posts: 1,157
Thaks, yes, carb model and no, it has new tank and fuel.

It seems similar to other problems I read about with low pressure fuel pumps bur I don't think I have one.
__________________
thomas is offline   Reply With Quote
Old 25 September 2011, 14:21   #5
Member
 
Country: USA
Town: Oakland CA
Length: 3m +
Join Date: Feb 2005
Posts: 6,653
Low pressure fuel pump is specified because of the way injected engines work: the low pressure fuel pump pulls fuel up to and into the motor, then the HP pump generates a higher pressure in the injector rail that feeds the injectors.

A non-injected motor will still have a LP pump, but it will simply be called a fuel pump since there is no other pump to differentiate it from.

You can usually ID a fuel delivery problem by squeezing the primer ball and seeing if things correct themselves. If so, the problem could be the pump itself, a leak in the fuel line (air ingestion), a plugged, kinked, or obstructed fuel line or filter, or insufficient venting of the fuel tank. Or several other things, but these are the most likely, I think.

jky
__________________
jyasaki is offline   Reply With Quote
Old 30 September 2011, 04:15   #6
Member
 
Country: UK - England
Town: NW& wherever the boat is!
Boat name: depends on m'mood!
Make: Humbers/15-24m cats
Length: 6m +
Engine: etec130/big volvos
MMSI: many and various
Join Date: Nov 2001
Posts: 1,815
carbs-float valves sticking shut due to lack of use and stiction ...??
__________________
Dave M
www.wavelengthtraining.co.uk
wavelength is offline   Reply With Quote
Old 02 October 2011, 03:28   #7
Member
 
Country: UK - England
Town: Sussex
Make: RIBTEC 655
Length: 6m +
Engine: Yam 150
Join Date: Oct 2007
Posts: 1,157
I had the carbs taken out and cleaned last week, put back and it was fine but as soon as we opened up yesterday it happened again on just one cylinder.

I replaced all the fuel lines, new tank and put fresh fuel in and there is a separator in line.

If he'd cleaned the carbs out would the float valves still stick?
__________________

__________________
thomas 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 00:01.


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