Onan MDKAL generator

Piers

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Joined
2 Jun 2001
Messages
3,599
Location
Guernsey, Channel Islands
www.playdeau.com
Anyone know an easy way to change the anode on this genny without allowing a half litre or more of seawater to flood the base? The anode is at the back of genny in the most inaccessible position possible.
 
It is absolutely critical with mdkal to install genset with space at right hand end. If they mounted it with right end inaccessible then tut tut. It's the only onan I can think of with this problem. Most others have the heat ex at the front.
It might be better and should be pretty easy to buy rubber hose and 1 inch grommets, and mount the heat exchanger outside the genset casing where it would be much more accessible.

If you never change the anode the heat ex will last 5-6 years

You could do what I do and have a tee in the raw water inlet, with hosepipe connection, and flush genset w freshwater when you aren't going to use it for a week. I have hosepipe inside e room to make it easier. Then you wouldn't need anode. You could even do it remotely if you bought a couple of motorised valves and fancied a little project.
 
It is absolutely critical with mdkal to install genset with space at right hand end. If they mounted it with right end inaccessible then tut tut. It's the only onan I can think of with this problem. Most others have the heat ex at the front.
It might be better and should be pretty easy to buy rubber hose and 1 inch grommets, and mount the heat exchanger outside the genset casing where it would be much more accessible.

If you never change the anode the heat ex will last 5-6 years

You could do what I do and have a tee in the raw water inlet, with hosepipe connection, and flush genset w freshwater when you aren't going to use it for a week. I have hosepipe inside e room to make it easier. Then you wouldn't need anode. You could even do it remotely if you bought a couple of motorised valves and fancied a little project.

There's little to no room to the right and access behind is impossible. I like the idea of a fresh water flush capability and I'll have a good look and see how to do it. There's FW to the engine room so shouldn't be too much of a prob.

Brilliant idea - thanks jfm.

Can't get the Pela into the pipes that access the heat exchanger - too many right angle bends. And being ashore cannot drain the unit given the vertical pipe risers associated with the exchanger.

So jfm's answer is the best. Again - thanks.
 
Anyone know an easy way to change the anode on this genny without allowing a half litre or more of seawater to flood the base? The anode is at the back of genny in the most inaccessible position possible.

Hi Piers, three weeks ago I did this on my MDKAZ. I use a wet & dry hoover, start to loosen the anode then run the hoover & hold the tube at the side/under the anode & gently loosen away letting a slow stream of water shoot into the hoover. Doesn't take long & voila no water in the tray.

A heating guy showed me this trick for taking radiators of when the drain cock sticks as they all do. Works a treat.

Paul
 
Fwiw here is freshwater injector on one of my gensets. You click a hosepipe on the brass hosepipe nipple at the bottom, shut the main intake seacock and open the freshwater valve. It's all 1.25 inch stuff.
photo-7.jpg
 
It's me Mr "awkaward question " :)
What's the risk of waterlocking the engine cylinder (s) ?-I mean the fresh water in is so strong it backs up in the exhaust manifold *and /or - from turning gen off too early before water off ? -and exhaust valve (s) is open = fills up

Or t,other way - @ start up - drying the impeller from not synchronising Gen on with tap on ?

Pressure from strainer s just passive 1m below W/L ish or less ., impeller just sucks sea water from strainer .
Hose pressure any thoughts ?

* assuming water leaves the Geny set via the exhaust manifold(s) .
 
Hi Piers, three weeks ago I did this on my MDKAZ. I use a wet & dry hoover, start to loosen the anode then run the hoover & hold the tube at the side/under the anode & gently loosen away letting a slow stream of water shoot into the hoover. Doesn't take long & voila no water in the tray.

A heating guy showed me this trick for taking radiators of when the drain cock sticks as they all do. Works a treat.

Paul

A really good idea. I was about to do just this when I wondered about blowing the seawater out of the system. I'd already disconnected the hose from the impeller to the heat exchanger (to see if the Pela idea would work) so I took a huge breath and blew down it. After half a dozen blows, air started to flow quite freely. Having removed the side and rear panels (how awkward was that!) I had access to the anode. Thankfully, only a few drops of seawater came out. Blowing had worked!

Now to refit the panels today....
 
It's me Mr "awkaward question " :)
What's the risk of waterlocking the engine cylinder (s) ?-I mean the fresh water in is so strong it backs up in the exhaust manifold *and /or - from turning gen off too early before water off ? -and exhaust valve (s) is open = fills up

Or t,other way - @ start up - drying the impeller from not synchronising Gen on with tap on ?

Pressure from strainer s just passive 1m below W/L ish or less ., impeller just sucks sea water from strainer .
Hose pressure any thoughts ?

* assuming water leaves the Geny set via the exhaust manifold(s) .
zero risk of any problem if you know what you're doing; some risk if you're a bit incompetent, though you'd need to be unlucky. . A comment you could make of boating generally!
 
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