No exhaust gas from thru hub!!

[dave3235]

HI ALL

Went out on my sib the weekend and noticed when looking down into the water by the engine, that exhaust gases were coming out mid leg and non was coming from prop.Even when powering up,the engine is a mariner merc 20hp 2 smoke serial no starts 953 and presume 1988.Also giving it the beans to get up on the plane I heard like a piong come from the water, I was thinking it may have been like an air pulse coming from the prop any one shed any light on this.

[dave3235]

Originally Posted by dave3235

HI ALL

Went out on my sib the weekend and noticed when looking down into the water by the engine, that exhaust gases were coming out mid leg and non was coming from prop.Even when powering up,the engine is a mariner merc 20hp 2 smoke serial no starts 953 and presume 1988.Also giving it the beans to get up on the plane I heard like a piong come from the water, I was thinking it may have been like an air pulse coming from the prop any one shed any light on this.

A call to Loco can you shed some light

[Festinghouse]

are you sure nothing comes throught he prop when revved up? its normal for exhaust to exit through mid section at idle, thats because the resistance of the water would stop the engine idling properly, but when the engine is working hard it has enough force behind the gasses to be able to take the quieter route through the prop

[dave3235]

Originally Posted by Festinghouse

are you sure nothing comes throught he prop when revved up? its normal for exhaust to exit through mid section at idle, thats because the resistance of the water would stop the engine idling properly, but when the engine is working hard it has enough force behind the gasses to be able to take the quieter route through the prop

Ah that sounds logical, i also have an exhaust outlet at the back further up, I thought that was what that could be. Don't supose you are able to shed any light on the piong sound from the water when throttleing up . It's the first time I have ever heard this, it was loud enough to be heard over the engine.Almost like a bubble bursting but much louder, like a sonic boom but in water! Strange

[Festinghouse]

sorry i cant help with that one, its a new one on me!

[jyasaki]

Is your prop tightened up? Loose props do a lot of weird things.

Other than that, no idea.

jky