OMC Exhaust Help

[gregr1971]

I plan on adding the bobs exhaust to my 1991 200 looper, i have stock jetting in it now, airbox and all is still on the motor.
What jets do i need ?
i run the texas coastline.

[oldschoolltv]

Why not just drill 2 half inch holes in the lower unit below the cavitation plate, sounds just as good and at idle it is quiet? and shouldnt need any jet changes as it wont help performance any, Matt

[gregr1971]

got a pic of where to drill?

[imq707s]

I plan on adding the bobs exhaust to my 1991 200 looper, i have stock jetting in it now, airbox and all is still on the motor.
What jets do i need ?
i run the texas coastline.

I have the exact same setup (almost). 1989 3.0 Looper, stock airbox, stock jetting, and a bobs exhaust snout. I didn't change any of the jetting, and it runs like a top. It actually gained 1-2mph on the top end with the exhaust snout. I also have the 2.7 heads on it, so compression is around 120psi I think.

I was thinking about going up on the jetting....but the plugs still look great, nice and dark brown.

When I trim the motor all the way down the snout is under the water and quiet, when I trim it up around half way...it starts to get a little louder. It's really not as loud as I thought it would be....nothing like my buddy's 260 promax with the offshore mid on it...that thing is LOUD at idle.

[gregr1971]

its hard to see, but i have one already on another motor, sounds GOOOOD!
i'm not real sue why all of the bolts in the lower though?? But thats how i bought it.
and i REALLY like these motor mounts!

[baja200merk]

its hard to see, but i have one already on another motor, sounds GOOOOD!
i'm not real sue why all of the bolts in the lower though?? But thats how i bought it.
and i REALLY like these motor mounts!

Thats where you drill the lower out, someone probably put a bunch of bolts in there to close the exhaust holes some one else put there.

[gfinch]

What ever you do make it so you can block it off when the sound police come to call.

[roadkill636]

I drilled 2 1" holes on each side of my lower and it was a bit too loud in the boat so I rigged up some "headers" out of 1" copper pipe elbows and tees and dirrected the noise strait out the back of the motor,
and they are easly pluged with boat hull drain plugs for when I want it quiet.

wish I had some closer pics, but its cold and dark outside now

(the levels are there to show someone on another site how to measure propshaft height)
"the jackplate is lowerd all the way"

[Kobie]

Roadkill636- What did the motor sound like before you put the brass pipes on it? Did it sound like a motor running off the hose or what? I was planning on drilling 2 holes on each side of my lower, and tapping them so I can screw regular boat drain plugs in them.

[hydromaniacc]

Here is what my 91 200 looper sounds like with a Bob's snout on it.
View My Video

[roadkill636]

I tried to (quiet) the noise before I added the piping and the drain plugs melted after a few hours,

I absoultlu LOVE the sound of the 4 1" holes in it but it was a bit too loud "inside of the boat, so I diverted it backward, with the jackplate down the pipes are about 1" underwater and has a real "burpy" sound, for when water patrol is arround the cove, and dosen't draw attention,.
but when I go fishing or pulling the kids on the tube I dont want to have all that noise and the boat drain plugs send all the noise out the prop, "QUIETLY"

I guess Ill go outside and get ya a better pic of it. I highly recomend it if you want a "choice" exhaust system for under $20
the pipes going into the LU are JB welded arround the outside and inside of the case, and there 2 #12 bolts cumming up thru the anti ventalating plate to secure them snugly, parts needed are
2 Ts
2 90* elbos
2 cupplings to fit on the inside of the t and the 90* elbo to hold them together

It's not as pretty as most motas here on S-F but i'm a cheap A** and you see what it's on...no regrets
4 #12 X 2" bolts
JB_-weld

[loop]

it needs paint pretty bad but its been on there since 2002
Greg let me know if your interested. you have my#

[loop]

2 more

[Laker]

2 more

Loop!
Didnt you tell me you were going to make us up a few of those!??
Check your PM
Chris

[gregr1971]

Loop,
im interested, is it a 20"