2008 Party Barge - Bad Prop Blowout

[mayorjones]

I just bought a 2008 Sun Tracker 21' Party Barge, and took it out for the first time today. It has a 2008 Mercury 50 hp 2 stroke. I boat on the Mississippi, and today had a TERRIBLE time with what I have researched to be (probably) an issue called prop blow out. The prop was seemingly starving for water, and I would have to idle it down to nearly nothing before it would "grab" again, but if I put any torque to it at all, it would start zinging - making lots of noise but not going anywhere. The really strange part was that it only did it going upstream, against the current. When I'd turn it around and go with the current, it ran great.

I live in Iowa and bought it from a dealer in Illinois, so I'm not sure how much help he's going to be.

Any ideas?

 

[tashasdaddy]

Re: 2008 Party Barge - Bad Prop Blowout

where was the load on the boat, how many people, majority of the load has to be astern of center, or the bow goes down and the stern comes up, prop out of water.

 

[mayorjones]

Re: 2008 Party Barge - Bad Prop Blowout

Well, there were four of us - my wife and three kids. They were sort of moving about on the boat, but nobody is overly large - a total of maybe 250 lbs or so. Even with that few do you think they'd have to move to the back?

 

[rickdb1boat]

Re: 2008 Party Barge - Bad Prop Blowout

The other thing is to make sure the motor is not trimmed out too far. You want it pretty much vertical to the water for starters.

 

[tashasdaddy]

Re: 2008 Party Barge - Bad Prop Blowout

my tnt on my motor is a complete waste, it has to be all the way down.

 

[mayorjones]

Re: 2008 Party Barge - Bad Prop Blowout

Oh', I had it fully trimmed down - again, the weird thing was that when I was going down stream, I could trim it up a little without a problem - but when going upstream, even if it was fully down, it would still blow out.

Very strange.

 

[Jeep Man]

Re: 2008 Party Barge - Bad Prop Blowout

Sounds like the rubber insert in the prop has broken loose. It's there instead of a shear pin. I'm surprised it happened on a one year old boat.

 

[mayorjones]

Re: 2008 Party Barge - Bad Prop Blowout

So what's that mean - new prop? If so, does anybody have a good suggestion on a good prop for a 21' pontoon w/a 50 hp Merc. The one that's on there now looks very "generic" - wouldn't mind spending a little money for increased performance if I knew of something that would work well...

 

[Jeep Man]

Re: 2008 Party Barge - Bad Prop Blowout

Maybe re-post in the prop section of the forum for more suggestions.

 

[SoulWinner]

Re: 2008 Party Barge - Bad Prop Blowout

Instead of a shear pin or key, Mercury props have a rubber insert that fits between the shaft and the propeller. It is not round, it's kind of squared off. If you take the prop off you'll see it. It absorbs shock and allows the prop to hit submerged objects and stuff without damaging the gears in the gear-case. So your problem could be your Master-Guard Hub (that's what the insert is called) or you could be propped all wrong.

 

[jessp]

Re: 2008 Party Barge - Bad Prop Blowout

I had something similar happened to me on my Merc 20hp on my Valco fishing boat. It would troll at low speed but you power up and the motor revs up very high, but does not go. The rubber inside had torn apart.