23' twin engine blowout problem

[hermco]

Tony,
If it was me I would try props first since you have high speed pickup allready and the motors are mounted high. The setup you have will give you the fastest WOT speed when you get the props dialed in. [img]images/icons/grin.gif[/img]

[REPETE]

I have a 75 Model 23'CC with twin 150 hp Mercs with 25" shafts on a bracket. The only props I could get to work were 17" and 19" Mirages. I ended up with the 19" because I turned them 5400 to 5600 and wanted the extra speed. They have never cavitated under any circumstance. I did try a pair of 4 bladed props which ran great as long as I didn't turn the wheel. The second I turned the engines, the outboard engine to the turn would blow out. If the mirages don't work you must have something throwing dirty water in front of your engines or they are indeed mounted too high.

[TonyS]

Thank you REPETE, are your props mirage 2 or the older mirage, because I was told the new mirage are better. The bottom of the hull is clean, no sea chocks or transducers. I had it sandblasted and barrier coated and painted with epoxy paint.

[REPETE]

They are the new Mirages with the plastic inserts. The inserts are supposed to take the place of the pressure installed rubber hubs. The diameter of the Mirage is such that it will not cavitate if its got relatively clean water. Most of my friends with Yamaha's run the Mirages also.

[Reel Smoker]

Toni, what is barrier coated.RS.

[TonyS]

RS, barrier coat system is a two part epoxy sealer used to seal water out of the gel coat. Its more waterproof then Gel coat and prevents water blisters. ( so it claims)