• Welcome to the Checkmate Community Forums forums.

    You are currently viewing our boards as a guest which gives you limited access to view most discussions, articles and access to our other FREE features.
    By joining our free community you will be able to:

    » Interact with over 10,000 Checkmate Fanatics from around the world!
    » Post topics and messages
    » Post and view photos
    » Communicate privately with other members
    » Access our extensive gallery of old Checkmate brochures located in our Media Gallery
    » Browse the various pictures in our Checkmate photo gallery

    Registration is fast, simple and absolutely free so please, join our community today!

    If you have any problems with the registration process or your account login, please contact support by clicking here or by using the"contact us" link at the bottom of the page.

drilling exhaust/midsection mercury?

It does nothing but get louder.

Now if you also dry stacked it... you would get increased midrange punch.

BUT for a lake boat its not worth it the effort. :bigthumb:
 
does it make it obnoxiously loud? its not worth it to me if its just over the top loud if its not going to make more out of the hole power
 
Knowing nothing about it, I was wondering if you could make it a little louder or is there just one way to do it. You say drilling I'm thinking different size holes.
 
well i am going to get bashed for this but oh well it def helps coming out the hole i have it done the old way with a 1 1/2 hole saw in each side just below the end of the tuner but also have the bobs exhaust housing with plugs in all the holes and the plugs out i feel a big difference. if you think about it when you dyno a out board it is out the water hooked to a machine with no back pressure from being sumerged in the water so you are doing just that with exhaust reliefs but i am also dry stacked to
 
When I bought my Predictor the PO had drilled out the midsection. It's obnoxiously loud, and when I plugged the holes (2 flat plates, a through bolt and some silicone sealer) I didn't really notice any difference in performance at all. I did notice that I didn't get a headache from the noise any more. I wouldn't recommend this mod at all.
 
I drilled and taped my holes and took the plugs with me to the lake. I put the plugs back in . way to loud . way, way to loud .way, way ,way to loud.
merc 200 black max.:shakehead:
 
I drilled and tapped mine as well. If you need a vented prop to get on plane, drilling the relief holes will make it impossible to get on plane. All (or most) of the exhaust will exit out of the holes and not through the prop. At the current time, all of mine exhaust holes are plugged and I have a new mid section waiting for paint and a swap out for the one with the holes in it.
 
Like anything else a lot of it is subjective. I have mine drilled with a Bob's snout on it and it isn't all that loud IMHO. I love the sound of a 2 stroke be it a piped three cylinder snowmobile, a single cylinder dirtbike, or a V6 outboard as much as or more than a V8 four stroke. With the relieved middle section on mine the same prop that worked well for Ram would not plane for me unless I made my wife and 2 kids go up in the bow and running solo I had to play with the throttle to get it on plane. The snout can be plugged although the plugs that come with it are about useless because they are impossible to get out. I am going to make a plate for mine to fit in the square hole and bolt it in instead.
 
I did it, I love it...

here is a vid of the motor that you can listen to...

http://www.youtube.com/watch?v=V4P-HuhT22w&list=UUtKZlMf_VVXbHJpPJU1dTZA&index=7&feature=plcp

this is an 86 XR2, i added velocity stacks, changed the jetting a bit, removed the exhaust tube, and drilled out the mid with 4-5 small holes per side, straight down right above the cavitation plate

does it perform any better, i can't say for sure... does it sound good.. in my opinion, yes..
 
chrispallen said:
I did it, I love it...

here is a vid of the motor that you can listen to...

http://www.youtube.com/watch?v=V4P-HuhT22w&list=UUtKZlMf_VVXbHJpPJU1dTZA&index=7&feature=plcp

this is an 86 XR2, i added velocity stacks, changed the jetting a bit, removed the exhaust tube, and drilled out the mid with 4-5 small holes per side, straight down right above the cavitation plate

does it perform any better, i can't say for sure... does it sound good.. in my opinion, yes..
Click to expand...

I have the exact same engine, and drilled them in the same spot. I tapped them as well, and currently I have all of the plugs in. I love the sound, but I needed the extra exhaust out through the prop to create a little slip for launching the boat onto plane. I have a few mods as well... Nice video:bigthumb:
 
atc250r said:
A bit of an apples to oranges since mine is an OMC but here ya go:

http://youtu.be/bCdYiUUiowA
Click to expand...


see this sounds really good, where did you drill it and what size holes? pics would be very helpfull. ive seen people drill the bottom of the mid section pointing straight down at the cavitation plate and also at the back of the mid section pointing out to the sides above the cavitation plate. i was thinking of doing it pointed out the sides at the back. any thoughts?
 
You must log in or register to reply here.
Back
Top