84 70 hp yamaha

fillet&release · 02-18-2009, 12:54 PM

I have a 84 70 hp yamaha I just rebuilt all 3 carbs and it seems to run lean. How can I tell if my oil injection is working right or should I disable it? Any advise helps thanks.
Zach

fishkisser · 02-18-2009, 02:32 PM

Take a look at your sparkplugs , they will tell you a lot about how your fuel mixture is doing ...

fillet&release · 02-18-2009, 04:56 PM

The plugs are what made me think it was running lean they are a light grey color but I wasnt sure if it was fuel oil mixture or air fuel mixture

Just-in-Time · 02-18-2009, 05:14 PM

only true way to to tell on plugs is this
new plugs
run it at WOT on the water for 30 seconds
pull the emergency stop switch
read the plugs

fishkisser · 02-18-2009, 07:35 PM

While its idling take a propane torch , turn it on but don't light it , and move it around the bases of the carbs and intake manifolds ...
If the idle goes up significantly you have an air leak on a gasket ...

If you could bypass the oil injector you could mix up a tank of gas and oil to ratio and see how it does compared to the auto system ...