exhaust riser to outdrive tube burst.

[jagilbert]

The prop on my merc 140 - pre-alpha has a flange-ring at the trailing edge of the hub that widens as it extends the hub length about an inch. This flange cracked and I removed it. The next time I took the boat out the rubber tube that connects down from the riser to the outdrive burst.

coincidence or related? I could imagine that the prop hub flange reduces backpressure while underway. Do I need to replace it?

What is that tube called?

A guy at the ramp suggested that the failure of that tube could cause water to enter the engine. I don't see why. Any truth to that?

Thanks,

 

[jagilbert]

Re: exhaust riser to outdrive tube burst.

Its called the exhaust tube: Exhaust Tube

Is there a general consensus of Mallory vs. Sierra?

Did the lost prop flange cause the failure?

Thanks!

 

[Kainon]

Re: exhaust riser to outdrive tube burst.

The removed prop flange wouldn't cause the tube to burst, running the engine without water will cause it to burn from the inside resulting in Failure. Someone probably overheated the engine at some point

The tube boot/bellows bursting wont let water enter the engine but it will enter the boat and exhaust fumes can be harmful.

I'm not sure what effect the prop flange has on performance of the prop or the effect on exhaust

You would need to ask that in the Prop section.

 

[jagilbert]

Re: exhaust riser to outdrive tube burst.

Someone probably overheated the engine at some point

um yeah, that'd be me :redface:

Thanks for the info.
Cheers