unburnt fuel or oil

[adam b]

wen i start up my 15hp yam it spits out fuel or oil out of the exhuast i cant feel it or see it come out but you can see it hitting the water i was wondering wether it was somthing to do with the carb letting to much fuel.

 

[cousinabe]

Re: unburnt fuel or oil

sounds like it could be a ruptured fuel pump diaphragm.

post full model number.

 

[Mas]

Re: unburnt fuel or oil

It's probably unburned fuel/oil mixture. Check the LU just to be sure. Look for signs of water intrusion/milkyness.

If LU is OK, you might be running rich.

MAS

 

[adam b]

Re: unburnt fuel or oil

thanks for your replys al check the diaphram tomorrow but could you please tell me what an lu is . i dont think it is running rich because it just started a few weeks ago an it makes a right mess in the harbour

 

[cousinabe]

Re: unburnt fuel or oil

LU is the lower unit. Possibly leaking oil and creating a slick on the water surface.

Most common causes of oil/fuel mist on water is a torn diaphragm in the low pressure fuel pump.

Post the full model number. This helps us figure out what engine we are talking about and provides more detail.

 

[adam b]

Re: unburnt fuel or oil

it is a yamaha 15de 1992 i think because the letter in the corner of the tag is B