Yamaha BS5 Outboard help?

KevO

KevO

Well-Known Member
Joined
10 Aug 2011
Messages
2,515
Location
Falmouth
Visit site
I've got a Yammy BS5 Outboard, 5HP. It came with a dinghy I bought but no manual etc. It has run fine all season until yesterday when it has started playing up. It seems to start ok but then dies at low revs. Then it struggles to start again for a bit. Once it's going it runs ok if I keep the revs on. Something gummed up with crud maybe?

Anyone had one and can suggest what (and how) I should take off and clean or whatever? Like I say, I have no manual and although practical, I am not a mechanic. :rolleyes:
 
KevO said:
I've got a Yammy BS5 Outboard, 5HP. It came with a dinghy I bought but no manual etc. It has run fine all season until yesterday when it has started playing up. It seems to start ok but then dies at low revs. Then it struggles to start again for a bit. Once it's going it runs ok if I keep the revs on. Something gummed up with crud maybe?

Anyone had one and can suggest what (and how) I should take off and clean or whatever? Like I say, I have no manual and although practical, I am not a mechanic. :rolleyes:
Click to expand...

Check that you have good powerful spark and then treat it to a new spark plug .

Clean any fuel filters.
Check fuel flow to carb if you are running from an integral tank.

If running from remote tank check fuel line for sources of air ingress esp the connector.
If running from a remote tank try pumping the bulb to see if it helps. Air in-leakage or dodgy fuel pump if it does.

A good chance that the carb will need a strip down and clean esp of low speed jet etc

Does applying a bit of choke help
If it does it reinforces the likelyhood that it needs a carb clean


Owners manuals back to 1998 at http://www.yamahaoutboards.com/owner-resources/owners-manuals

easiest place to look for parts lists and diagrams is probably http://www.boats.net/parts/search/Yamaha/Outboard/parts.html
 
Thanks for responding guys. I had already thought I would replace the plug... I found it located at the back of the engine but what bit is the carb? I will try to upload some pics from this mobile but haven't had much luck so far... Not a very good signal from my mooring in Falmouth harbour.
 
but what bit is the carb?
Click to expand...
Carburettor ..... but nobody can spell it ... the Americans cannot anyway!

The bit where the petrol ("gas" if you are American) and the air go in

Located on the front of the engine .. but if you dont know what a carb is or don't recognise it I hesitate to suggest you dismantle it to clean it.


I dont know the age of your engine but similar to this probably. http://www.boats.net/parts/search/Yamaha/Outboard/1984/5LN/INTAKE/parts.html

A few years later but a clearer diagram:

INTAKE.png
 
Last edited:
I finally took the engine in to a workshop. It turns out that the problem was the coil which is now defunct (I actually typed defuct there originally which is actually quite apt). :rolleyes:

I have tried google to no success, I can't seem to find anything listed for engines pre-1984 (my BS5 is 1980 I believe). Any ideas where I might be able to find a coil for this model?
 
You must log in or register to reply here.

Share this page

Top