Yamaha 60hp Fuel problem

[Dr Jizm]

Basically my 1996/1997 60hp is cutting out and refusing to restart after being run for a while. I was out and cruising along at about 25knots and I slowed down to stop and put it in neutral and it died and then refused to restart. Had to get towed in. Took it home and cleaned all the fuel system right thruogh and the carb main jets. All seemed ok running in a water bin in the garden. Took the boat out again today to check all is ok and it isn't. It did exactly the same. Fine for a while then cut out and died as soon as I stop for the first time. Now it starts and runs for a few sconds then dies again.<br />all help much appeciated. Thanks

 

[JB]

Re: Yamaha 60hp Fuel problem

Sounds like a vacuum lock in your fuel tank, Doc. Check the vent for a clog.<br /><br />Good luck, and welcome aboard.

 

[Dr Jizm]

Re: Yamaha 60hp Fuel problem

Pretty sure it's not that, but will double check anyway. It seems to be when the engine gets up to temprature the fault appears. Could this problem be to do with the pilot jet? If I get the motor to start and then rev it it seems ok but when I go back to idle she dies and refuses to restart!<br /><br /><br />PS: I have been a member for a couple of years nut changed my Pc and isp so lost all my old log in details!

 

[ianyoung77]

Re: Yamaha 60hp Fuel problem

When it refuses to restart have you checked the spark and tried spraying blended fuel in the carby?

 

[Dr Jizm]

Re: Yamaha 60hp Fuel problem

Ok I just cleaned the carbs out again this time made sure I did the pilot jet and all that. Now she starts lovely and revs lovely but will not idle for more than 30 secss without coughing and dying. It will then restart and do the same again.I am starting to pull my hair out now!!!

 

[douglloyd]

Re: Yamaha 60hp Fuel problem

Sounds like you need to turn out the pilot jet screws. Go out one turn then if that works turn them in a quarter turn at a time until it quits again (give some time between each adjustment for the carb to catch up) then turn it out a quarter and you should have it. Warm motor at idle in gear in water.

 

[Dr Jizm]

Re: Yamaha 60hp Fuel problem

OK. I have had the fuel pump off and checked the diaphragm, all ok. Did what bluebird said and still no difference. Check the spark plugs like ianyoung said and all seemed ok but I replaced them anyway, I started it up and it has just sat there at idle long enough to heat up the water in the bin it is in to the temperature of a hot bath! It did cut out after about 10-12mins of idling but started straight back up and idled again for a few minutes. Would the temperature of the water it is in affect it? Engine is now quite hot.Is it worth going out for another sea trial do you think?

 

[sherwindu]

Re: Yamaha 60hp Fuel problem

Just a guess, but are you working with fresh fuel?<br />If not, try changing out your fuel tank with fresh<br />stuff and see what happens. Fuel older than a few<br />months or even less without a stablizer treatment<br />can go bad on you, causing erratic performance.<br /><br /> Sherwin D.

 

[Dr Jizm]

Re: Yamaha 60hp Fuel problem

Yes I have used fresh fuel,good point though. I am pretty sure the spark plugs have cured it but I won't know for sure until I do a sea trial. <br />To be honest there is not much more to it. I have a yamaha motocrosser and that will run fine one day and not start the next, always the plug, just goes with no warning at all. I think the plugs may be fouling up though, anyone else had that?

 

[sherwindu]

Re: Yamaha 60hp Fuel problem

Another thing to check is if your gas tank is venting properly. Check the squeeze bulb after the<br />engine dies. If it is not firm, this may indicate<br />a fuel feed problem. I would also suggest an inline<br />fuel filter from the tank with a glass viewing window, so you can see if gas is coming from the tank. It also protects the engine from dirty fuel.<br />Use a 10 micron filter for this purpose.

 

[Dr Jizm]

Re: Yamaha 60hp Fuel problem

thanks for your advice. Does anyone know the base pilot screw settings for the yamaha 60?

 

[ianyoung77]

Re: Yamaha 60hp Fuel problem

I haven't got the book for 1996 but 1992-5 was 1 1/2 turns out if that is any help

 

[Dr Jizm]

Re: Yamaha 60hp Fuel problem

thanks, much appreciated.

 

[Jan Z]

Re: Yamaha 60hp Fuel problem

I just went through this with a new motor (40hp 4 stroke) and the cause is the ethanol based gasoline that california is switching to.<br />The ethanol collects water and the water/ethanol will corrode your carbs and clog your jets.<br />The fix was carb rebuild, different jets and a Raycor water/fuel seperator set up with a ten micron filter.

 

[Dr Jizm]

Re: Yamaha 60hp Fuel problem

thanks, will look at that.