ThirdBird

Buddy bought an '87 32' Pachanga, 454 mags. Previous owner re-routed the thru-hull exhaust to the props. Buddy has all of the original exhaust plumbing to put it back to original. Question is, do the engines have to come out to do this exhaust swap? Been told yes but it doesn't appear to be required that the engines come out.

ajl marine

if the bullhorn assemblies are still in place but have been capped off then there would be no need for engine removal,just make sure the splash flaps are still in place & working . be agood idea to ckeck & replace your riser gaskets at the same time. cheers ajl.....

ThirdBird

I'm surmizing the the "bullhorns" you refer to are the 5" exhaust tips through the lower hull corners. If so, yup, still there, just capped off.

When we disconnect the through-prop plumbing, how do we cap that off down there at the Alpha drives?

Rippem

The bullhorn is the Y down-pipe that takes the exhaust down to the transom assembly for thru prop exhaust.

originally there is a log "can" (kinda looks like a heat exchanger, 'cept it's 6" in dia or so) across the back on each engine. the rubber hose from the risers dumps straight back into this. This in turn dumps with rubber hose from the outboard end, into an AquaLift muffler in the corner, then rubber hose to the thru-hull from the muffler body.

Big can 2/3 full of water...the simplist most effective muffler idea.

Are all the original parts with the boat?

ThirdBird

Yeah, all original. Just don't know how to cap-off the thru-prop set up.

1BIGJIM

iTrader: (1)

My Pachanga has a cap/plate over it and has no exhaust bellows. There was a thread in the last few weeks about removing the Y pipe and capping it.

bbcngineer

Thirdbird,

Mercruiser makes a block off plate for the transom assy that blocks the opening at the transom. I believe that the motor needs to come out in order to install the block off plates. You can block / cap this off in other places, however you run the risk of adding another joint at or below the waterline (potential to leak and because of their size could sink a boat quickly). The dealers and manufacturers would never recommend this. Bottom line; to do it by the book you should use the block off plates. I have never put these in maybe it can be done with the motor in.

ThirdBird

Well, maybe that's why I'm being told the engines need to come out to put the exhaust back to stock (Pachanga stock). I've been looking at it and can't see any reason for the engines to come out to put the original exhaust back in. But,,,,,,,, to put the block-off plates in,,,,, maybe so.

Thanks bbcngineer, I'll investigate some more.

US1 Fountain

iTrader: (1)

You can buy PVC caps and clamp them to the top of the bullhorns with the rubber hose. Seen that done many times until the motors come out to remove the horn all together.

hillbilly24

ok no offense guys but can we quit calling the Y pipe the bull horns? not all y pipes have round ends alot of them are oval and can't be capped with a round object. You defenitly have to pull the engines to install the blockoff plates, it's not a matter of haveing small enough hands to get in there the bolts hit the bellhousing long before they are unthreaded even if you could get your hand in there. I would not recomend blocking it off any other way then useing the block off plates its too big of a hole and too big of a risk. You dont have to pull the engines all the way out either you can just slide em foward about a foot if you have the room. If not pulling them all the way isn't a big deal, ussualy the worst part is dealing with the exhuast which is the reason your pulling them anyway. Other then that it only takes about 15 minuits to get the engine out.