3 inch or 4 inch [Archive] - The Donzi Registry

lee

01-02-2005, 10:08 AM

my boat came with 3 inch exhaust tips and i'm switching to a merc 454 will i need 4 inch exhaust tips or bigger or can i get away with the 3 inch

Cig Man

01-02-2005, 03:26 PM

Hole saw the transome out to 4 1/2" ,glass the edges of the holes and go with 4" you will regret it if you don't.PM me if you have any questions on how to drill the transom.P.S. I did this on my 20' Cig.

Rob

ChromeGorilla

01-02-2005, 03:42 PM

can i get away with the 3 inch

Only if she doesn't mind! :rolleyes: :bonk: :wink:

lee

01-02-2005, 04:20 PM

how did you cut it
\
Hole saw the transome out to 4 1/2" ,glass the edges of the holes and go with 4" you will regret it if you don't.PM me if you have any questions on how to drill the transom.P.S. I did this on my 20' Cig.

Rob

lee

01-02-2005, 05:16 PM

merc
Which 454???

lee

01-02-2005, 05:48 PM

sorry i think 365 375 i'm not sure the engie is a friends and in his garage is a spaRE FOR HIS BOAT
OK, I should have clarified that a bit: :bonk: :) :) :)

What HP Merc ya using??

MOP

01-02-2005, 08:23 PM

If you do decide to go to 4" Murph told me a good trick, get you holes saws out and find one that fits the existing hole then put it inside the 4-1/8 on the same Collete. the small one keeps the big true so it cuts very well, once you are in the transom about 1/2" take them apart and finish the job with just the big hole saw. I wish I had learned that trick many years ago, I cut a few hundred the hard way. Thank Murph for that one!

Phil

Gary

01-03-2005, 10:25 AM

What boat is this for? I ask because I had an 86 Z-25 with a TRS drive. It had 3 inch exhaust. I didn't have enough room for 4 inch because of the way the steering ram is down low on the TRS drive. Make sure you have the clearence inside the transome before you cut.

Lenny

01-03-2005, 11:55 AM

You can also "re-cut" holes with hole saws this way. I get a piece of wood, spray on some contact adhesive to it and in this case the inside of the transom as well, wait a bit and press it into place. Then from the outside of the hull you can start with a fresh "center" again into the cleam wood and guide your way through with a larger holesaw and a fresh cut.

I do this in wood all the time and it works fine. Only I usually clamp a temporary piece of wood in instead of contact. It should work fine for you.

Formula Jr

01-05-2005, 12:18 PM

I agree with MP, going to fours will not do much more than make it louder on a slow spinner like a 454. Too little for too much work.

Moody Blu'

01-07-2005, 07:59 AM

I agree with MP, going to fours will not do much more than make it louder on a slow spinner like a 454. Too little for too much work.
What i did was screw a piece of wood through one of the old tip mounting holes and used a 4" hole saw. The wood keeps the saw aligned. It took me 5 minutes to do both.
They fit nice and snug with the 4" blade which means less sealing material is needed to keep the water out

mattyboy

01-07-2005, 08:11 AM

I'll say a snug fit, so snug the beauty rings don't need screws ;) :p :eek:

Moody Blu'

01-07-2005, 09:42 PM

I'll say a snug fit, so snug the beauty rings don't need screws ;) :p :eek:
YOUR RIGHT! i used the 4"exhaust hose clamp to keep them on the transom!!! :p

Air 22

01-08-2005, 07:50 AM

4 inches has gotta be better than 3?? :rolleyes: :p :biggrin: :smileybo: :bawling:

mattyboy

01-08-2005, 07:58 AM

4 inches has gotta be better than 3?? :rolleyes: :p :biggrin: :smileybo: :bawling:

yes for the most part unless we're talking about snow :) ;)

Air 22

01-08-2005, 08:29 AM

yes for the most part unless we're talking about snow :) ;)

Snow is kinda like sex..ya never know really how much your gonna get :D ....and how long it will last :eek!: :hyper :biggrin.: :
Poodle...u gettin this down there soooooo close to Cuba? :alligator The the only snow you guys might see is powdery white stuff that we in the Coast Guard couldn't find a way to ski on :biggrin.: :biggrin.: