How to Drain the water from manifold and riser?

[simon3055]

Hi there,

I just got a Bayliner 3055, I plan to replace the manifold and risers.

When I read the service manual, it mentioned to drain the water first, I have no idea how to do it.

A liitle about the boat, 1999 bayliner 3055 with twin 305 mercruiser 5.0 carburetor. the manifold is the central manifold.

I've got all mercruiser part, will do it this weekend. Any advise will be appreciated!

[simon3055]

I got a quote about 2K for labors, I would like to save some $$$ if it is doable.

[Nauti_Mike]

On the bottom center of the exhaust manifold there is a water elbow where the coolant hose attaches, it should have a drain plug on it else just remove the hose and it will drain both the manifold and riser.

[Squiddy]

Simon, I just did this job myself and glad to help you. I was talking to Nauti Mike about it on Maxum forum. It was not difficult and you can definitely do it yourself.

Make sure you have the gaskets for the manifold and elbow. A torque wrench is good to have also since you want to tighten the bolts in 3 steps.

There are numerous videos on youtube for doing this. A good tip that I used was to install stud bolts to facilitate removing the manifold. To do this, remove the two end bolts from the manifold and replace them with studs. Then remove the remaining bolts and slide the manifold off using the studs to support the weight. Studs also help with getting manifold and gasket aligned for install. Manifold bolts are .375 x 16 x 4inch. I got bolts and sawed off the heads and created slot for screwdriver. 3.5 inches is about right length.

I also needed to apply a little dilectric grease on then new elbow to help it slide into the rubber exhaust hose.

All went smoothly. You may want to change spark plugs while you got manifolds off.

[builderdude]

Assuming the exhaust is raw water cooled you can drain as Mike suggested. Are you doing all four sets or just one? A good idea to look at them all while things are drained.



Attached files

[simon3055]

Thanks for the pictures, I am pretty sure it is a raw water cooling system, so where is the drain plug? is it the plug in the pic? I think I have the exactly exhaust elbow and manifold, I dont think I have the extra spacer.

[simon3055]

Thanks, I am pretty sure it is a raw water cooling system, so where is the drain plug? it located at end of the manifold? should I throw a bucket to hold the water from the pipe? I think I have the exactly exhaust elbow and manifold, I dont think I have the extra spacer.

[Squiddy]

Starboard side view, directly under the exhaust manifold

[builderdude]

There may not be an actual drain plug located at the elbow, like Mike said removing the hose from the elbow at the bottom of the exhaust manifold will drain the exhaust down.

[bhawes]

There is usually a blue drain plug (plastic of some sort), screwed into the bottom of the manifolds. If you haven't got a clear view of the bottom of the manifolds use a small mirror and a flashlight to locate it. Unscrew this plug and any residual water should drain out. The water hose has to come off regardless to change/remove the manifold, so I usually only remove the plugs for winterizing, but they can be removed prior to the hose if desired.

[simon3055]

Thanks guys, this place is amazing, I was so confused before.I will do it this Saturday and I will bring some pics for the record.

[Tommo]

Hi guys i have a bayliner 175 and i was just wondering if it is necessary to drain the water hoses time to time?

[Nauti_Mike]

Hi guys i have a bayliner 175 and i was just wondering if it is necessary to drain the water hoses time to time?

You did not say where you are at in the world but if you are in an area where freezing occurs then the entire cooling system needs to be drained. Other than that flushing with fresh water (hose) is recommended after use.

[2850Bounty]

Hi guys i have a bayliner 175 and i was just wondering if it is necessary to drain the water hoses time to time?

Tommo, you have posted to a thread that was started back in September of 2017.
It's always best to start a new thread for your specific topic!

[ouyoutouchmytalala]

To drain a motor:
Remove the block drains and probe to make sure they do in fact drain
To drain manifolds:
Remove hoses at the bottom of the manifolds or remove the drain plugs to drain manifolds/and/or risers
Should you desire to fill the motor, simply pour AF into the manifold hoses untill it comes out the exaust. For the motor remove the large hose from the therm housing side and pour AF into the block untill it comes out the therm housing