Valve noise from a Yamaha 40

SEA3PO

New member
I have a 3 year old Yamaha.....that has idling problems.... Today after about a 2 hour run at 4800 rpm (from Santa Barbara to Channel Islands) it idled just fine but made loud valve noise..... I can't imagine it was hot.... but what else would cause valve noise at idle ?? This happened about a year ago...I took it to the dealer...and they said there was nothing wrong and they could not hear the valve clatter....so it must be heat related ....right ???

Ideas anyone ??

Thanks

Joel
SEA3PO
 
SEA3PO":2znset7w said:
I have a 3 year old Yamaha.....that has idling problems.... Today after about a 2 hour run at 4800 rpm (from Santa Barbara to Channel Islands) it idled just fine but made loud valve noise..... I can't imagine it was hot.... but what else would cause valve noise at idle ?? This happened about a year ago...I took it to the dealer...and they said there was nothing wrong and they could not hear the valve clatter....so it must be heat related ....right ???

Ideas anyone ??

Thanks

Joel
SEA3PO


Check the oil?
I had the camshaft / timing belt tensioner on my F-100 Yamaha make a tick, tick, tick whenever it felt like it.This was after about 500hrs. I replaced both all is well. Hook up the Muffs take off the cover run it & look and listen :mrgreen: :beer
 
Thanks...I will check that this morning..... Yes the oil is fine...first thing I checked.... and not overly hot or burnt smelling... (this is why I doubt overheating) but I had never thought about the tensioner...it is in about the right area...

Thanks

Joel
 
Amazing !!!! I pulled the cover and started the motors.....they run fine at high speed....but both motors shake when they idle.....
I took it to Pacific Marine in Oxnard for that problem.....about a year ago...they said they tuned it and it was fine.... they coulden't find anything wrong with it..... well Dah !! I just wonder how they adjusted the carbs without pulling the plugs over the adjustment screws.... it idled fine when it was new....but now that it has almost 300 hours on it...the carbs need to be adjusted.... they sure diden't have any problems charging me $300 for a tune up ......other than changing the oil and filter and the plugs...I wonder what they did ??? not much..
I just know that if I take it back they will tell me that my carbs need to be rebuilt...... nope...just pull the plugs and adjust the carbs...easy enough..

I really feel they cheated me.

Joel
SEA3PO
 
That was it...... once I pulled those plugs and adjusted the needles it idles just fine..... got the shake down to a minimum....and the motors start a whole lot better too... Sure makes me think about repair shops..

Joel
SEA3PO
 
SEA3PO":17dhkqms said:
That was it...... once I pulled those plugs and adjusted the needles it idles just fine..... got the shake down to a minimum....and the motors start a whole lot better too... Sure makes me think about repair shops..

Joel
SEA3PO

They aren't all like that :wink:
Glad you got it handled! :mrgreen: :beer
 
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