Fuel and Oil Dripping from Prop

[Salty Dog]

I have twin 91 250 Yammies which both run fine. The starboard motor at WOT is 200 rpm less that the port (could be a cable adjustment). When I put the boat on the lift there is fuel dripping from the prop hub. Any ideas what would cause this? nIt seems to run too smooth to be misfiring.

 

[zzzzz]

Re: Fuel and Oil Dripping from Prop

think of your engines' midsection as a chimney...after years of building up "soot" sometimes it will start to let loose and start to ooze out causing one to think they have a gear oil leak or another type of leak...could this possibly be it ?

 

[rodbolt]

Re: Fuel and Oil Dripping from Prop

smell it
if it smells like gas then check your ign,compresion,fuel pumps and carbs, if it smells like dead shrimp check your gearcase oil.
if its fuel its comeing from either an engine misfire or something is dumping raw fuel into the crankcase assy then it gets pushed out the exhaust where it mixes with carbon and drips out as a sludge.
its NOT normal with a 250.
but you do need to determine is it fuel or gear lube and take the appropriate course of action BEFORE it gets expensive.

 

[Salty Dog]

Re: Fuel and Oil Dripping from Prop

Thanks, it's not gear oil but might be fuel + oil. The motor seems too smooth to be misfiring though. How do I test the fuel pumps?

 

[baiwan]

Re: Fuel and Oil Dripping from Prop

Check up the spark plugs. When the fuel pumps don't work the motor doesn't.
Fuel pumps fill the crankcase with fuel while the engine is working, you get rich mixture and rough work and no idle.