• From: Ottawa, On
  • Registered: 2005-03-10
  • Posts: 353

Topic: Engine Exhaust Setup

Getting closer to the water!!  I'm having to reinstall the engine, and I was wondering what kind of setups there are out there.  My problem is that the though hull is 1-1/4 threaded, but the yanmar exhaust elbow and waterlift both are 1 3/4" hose.  You can't get a 1.25NPT to 1.75 barb adapter....  Least I cant find one anywhere in bronze.  What kind of setups are out there cause I need some ideas!

stefan_d's Website

  • From: Hamilton, Ontario CANADA
  • Registered: 2006-04-06
  • Posts: 148

Re: Engine Exhaust Setup

Since your boat's still on the hard, why not just change the thru hull to match the hose sizes?  Just a thought.  Good luck on your impending launch.

Cheers!

José

jcfoto's Website

  • From: Vancouver, B.C. Canada
  • Registered: 2005-05-06
  • Posts: 304

Re: Engine Exhaust Setup

Yes, Jose makes a good point...the less joints the better, as you don't want it to fail at a joint, and then not have a replacement, and that is where it will leak, of course! ;-)

Check out Fastening Places for all sorts of joints and barbs etc. 

Good luck...make sure the slings stay on your boat, (or it stays on the trailer) for a good 20 minutes until you check for SURE It is not leaking.

“You get a boat for only one reason, because you want one.  If you’re worried about being practical, forget boats.”

4 Reply by Ian Malcolm (edited by Ian Malcolm 2008-08-19 06:16:11)

  • Registered: 2006-09-20
  • Posts: 175

Re: Engine Exhaust Setup

As someone who has had the engine, shaft and stern tube out and finished getting it back in a mere hour before the booked craneing in, (*NOT* reccomended, I tied up the lifting berth over the fortunately non-working weekend hooking up the fuel, exhaust and electrics),  change *any*  thru-hulls you aren't 100% confident of. 

The exhaust one should be above the waterline so its not going to sink you but the cooling intake and any  galley or heads ones and any thru-hull tranceducers must be in A1 condition with good sealant and backing blocks glassed in place.

Make sure that all seacocks and your stern gland are perfect and then you can launch with confidence and with a little talc around  the possible problem areas to show up any weeps early, you'll be able to check them before you have to pay for extra time in slings.     

Replacing anything iffy that you cant shut off with a known good seacock is a lot cheaper  than paying for extra crane time or lifting out again.

Change out the Exhaust through hull, you *dont* want the extra back pressure from a restriction.  If you are reinstalling the same engine, change  the exhaust hose from the engine to the waterlock if you've had  any overheating  due to blocked water intake etc.  Inspect the waterlock carefully and replace if  its been overheated (the inlet barb can collapse under the jubilee clip) or there is any cracking from frost damage.   

Replace the cooling intake hose, the liner on some types of hose can collapse under suction with nothing visible externally once the bond to the reinforcement weakens with age - pick up a little weed and you may not be able to restore cooling flow even after clearing the filter or you may get random overheats you cant track down.  The rest of the cooling system  after the pump is under pressure and if the hoses are sound and the anti-syphon loop  vent tests OK can be reused .