xwing

Do 4" Gibson Powercurve turndowns fit on STAGGERED engine setups?

2007 42' Fountain with 700sci's/SSM6 drives, 4" exhaust pipes, got ticket for noise in Wisconsin on Lake Michigan.
Wisconsin require 86db at 36" from exhaust at idle. Gibson claims <88db and on plane hopefully no loss in HP/MPH.
BUT: Measured for this and the CENTER 4" exhaust pipe (between the 2 SSM6 drives) space is too narrow with the plastic covers over drives right off transom; with the plastic covers off it MIGHT fit but not sure, will be CLOSE and with turning drives may interfere.
Starboardmost pipe is all alone and fits fine.
Port has 2 pipes to left of lefthand drive and should hopefully fit, maybe angled a bit away from drive.
That MIDDLE pipe between the drives will be the issue!

Has anyone done downturns on Fountain staggered engine setup, and advice?

dereknkathy

You have an old thru prop merc exhaust elbow? Stick a merc boot or piece of 4 inch hose on the exhaust outlet and clamp the elbow on. Then see what you have for clearance and what adjusting you have to do.

SS496

WOW! You got popped out on Lake Michigan?! I thought the LEOs left you alone concerning noise out in the big lake.

underpsi68

Look into GGB inserts. They slide inside of pipe and don't affect hp.

Got Freedom?

I have Gibson downturns on my 42 with 700SCis and staggered #6 drives and they work great. They will fit but the two on the port side need to be angled a little outwards to clear the plastic transom assembly cover. No issues with the center one, it clears just fine. I also run on Lake Michigan and haven't had an issue since I installed them.

GF?

xwing

Got Freedom: ok thanks for specific experience on same boat, will have to see how that center one fits because with covers on there just isn't 4" of space! Got to try and/or MAKE it work though...
Thanks for the other peoples' answers and info/help as well!

TomR

Any concerns with reversion?