Winterizing an inboard (long)
This was started on previous post - but thought I'd stand it out as it's own topic.
As I have just changed my outboard powered boat - and this new Maxum has an inboard, (4.3L carb )my winterizing scheme will have to be thought out again.
Assume end of season (hoping to get out at least once more) … post use each time will be to flush on fresh water with muffs – run till warm to ensure stat opens.
Then switch to in-line X-salt dispenser to dissolve any residual salt and coat the internals.
The rinse down outdrive leg with same solution via hose.
The advice seem to between use in-season to not drain down the engine (there are plastic drain *beep* for the purpose.
At last use of season the advice I am finding in many places is that you do the above … then in parallel actions fog the engine & run in anti-freeze, stalling engine once anti-freeze start coming out of the exhaust.
This coats cylinders and manifolds in oil, and leaves anti-freeze in the water ways …. I had thought of fully draining but advice is that it’s less corrosion if you fill it with ant-freeze.
I have found a couple of suggestions on how to do this …. I’ll list 2 below – be happy to receive comments from anyone who has experience of this.
Run to warm on fesh water, After you have flushed the engines on the hose it's a good idea to run some antifreeze through the system.
Get a 5 gallon bucket, with an outlet in the bottom with a tap, that can connect to your engine muffs with quickconnect fitting.
Mix up a 50:50 batch of antifreeze and water.
It's good to use a short (6 foot long) garden hose that has the
engine flush muff at one end.
Remove the flame arrestor from the carb and have a can of fogging oil close by.
Fogging oil now comes in spray cans. Mercruiser's fogging oil is
called Storage Seal and works great. You can also use a quart can
of Marvel Mystery Oil if you like. (or any 2 stroke)
It's a good idea to have a friend on the outside of the boat watching
the garden hose and monitoring the fluid level in the bucket.
This all has to happen smoothly!
Have the bucket as high above the engine as you can arrange it safely.
Assuming engine is well warmed up, switch hose to bucket, open tap, start the engine and let idle while observing the fluid level in the bucket.
Before the bucket is empty, start to fog the engine but don't let it stall.
Just before all the fluid is sucked out of the bucket, stall the engine by fogging at a faster rate – or simply operate choke or turn off.
If you notice antifreeze coming out of exhaust then you can proceed direct to completion of fogging rather than waste what is in the bucket.
Once the engine has stalled, stop fogging.
Reinstall the flame arrestor and plastic cover if supplied.
Flush through, run to warm.
While idling, fog the engine, stop and open all the petcocks to drain. out the water. Close all the petcocks. Drop the oil cooler hose to drain it and also the water recirculating pump main hose.
Reconnect both hoses and pour -100 F. anti-freeze into every hose at the T'stat tree until it runs out the back; about 1/2 gallon per hose for the manifolds, 1 gallon for the recirc. pump hose and 1/2 gallon for the lower right T'stat raw water inlet hose.
Having completed ver 1 or 2, some people advise to leave the engine as is from this point, others recommend that the block and manifolds be drained.
Fully drain the block, pumps & manifolds (5 petcocks on my Mercruiser)
The large water hose on the front of the engine should also be removed
as it will puddle water even after the block is drained.
Would welcome advice.