Volvo MD7A

[Restlessone]

I have a chance to get a Niagara 31 that has been abandoned.

The engine starts and runs well and there is no sign of water in the oil. If you are in the cabin looking into the engine compartment you can see water coming out on the starboard side of the engine. It appears to be coming out up near the top and near the middle of the engine but on the side. The cabin side of the engine has the frost plug missing and is no where to be found.

I don't know this engine and am very reluctant to start removing pieces.

Any help would be appreciated.

Gordon

[gjordan]

I have seen the whole MD7 manuals on line. See what you can find. A good engine if it has not been neglected for too long. There are several very good threads here on CF about the MD7A. Best of luck. ___Grant.

[Captsteve53]

Not a bad little engine 2 cylinder over all around 14 hp from memory, if you can see a missing frost plug then definitely will result in major water loss so be careful running more than a few minutes,

Frost plugs are easy to replace and readily available at most auto shops(just need to know size-measure the hole accurately) frost plugs come slightly curved and can be installed by giving then a tap with a hammer - I usually clean the hole well and also use a little gasket glue in the hole to be sure of a good seal.

Its unusual to have a frost plug fall out but not impossible, Volvo's earn there nick name (the green death) for a reason.

[Don C L]

My buddy has one that we took out and had it rebuilt by a mechanic friend. It ran well before and it still runs well, only now it cools itself properly. I know parts are hard and expensive to come by, but I think it may still be a toss-up between rebuilding it and switching it out for a Beta. How much of a DIY guy are you? I think it's a good little engine once it is not leaking AND is pumping water through freely. The old raw water cooled engines get a black gooey crud that builds up. Once it is out it needs a flush with CLR or something once in a while to keep the lines clear.
Search MD7A here, you'll find a lot more.

[Restlessone]

Thanks for the comments.

I'm more concerned with the water coming out of the side of the engine. It's behind the impeller so I can't see if it's a crack or something else. Another interesting thing is when the engine is running the water doesn't reach the frost plug. You can see it bubbling it there but it doesn't get high enough to come out the hole.
I have looked for hours on line and can't find anything that relates.

Thanks.