Thru Hull Exhaust - need pointers

[guido4512]

Greetings
Need to know all I can about installing a thru hull exhaust.
Boat will have 4" side exit tips and Corsa quiet choice. The manufacturer recommended not to go thru the transom.
Any pointers to make this go smoothly? I have the pipe routing figured out
Need to know where to place tips- as in -how many inches up from the waterline? Also how do the tips seal with the hull? Whats best to use to cut the holes - they are not round (oval).
Any help appreciated.

[flat broke]

There was a decent article on installing a silent choice system in this months Family and Performance Boating Magazine.
Chris

[blownfear]

guido, if the tips you plan on using have rubber flappers you really dont have to worry to mush about above or below water placement (above water sound better in no wake zone)but you want to keep them lower than the p trap in your headers. I used clear permatex silicon when i did my tips 2 yrs ago , no leaks yet.
Use a hole saw a little smaller than you need and use a jig saw for the final cut and keep the hole as small as possible.
GOOD LUCK,.........Dan

[Rexone]

On cutting the hole, use a "fine" jigsaw blade for a smoother cut and less chance of biting and chipping. Also I would tape the area with duct tape (heavy tape) first and draw out your pattern on the tape. The tape will help keep the holesaw and / or jigsaw blade from chipping the gel at the edge of the hole. It will most likely be behind the tip flange anyway but a clean hole is always nicer than a chipped hole (no need for hole comments gentlemen)..
I would use clear marine silicone for the seal and don't overdue it. There is stronger stuff out there but not necessary and makes uninstallation tougher risking gelcoat damage at that time. I would coat the inside of the hole with resin also even though it is glass.