Valmet 7 hp 2-stroke engine

[Guest]

There is a 12 hp version about too. We inherited the 7 hp with a boat we rebuilt and have found that despite appearing a rugged marine engine, it gave us quite a few problems due to excessive backpressure from the waterlock, which now seems sorted, and pushes 5 knots in most conditions. But would be glad to know more from anyone whose come across it and any tips.

 

[oldharry]

This sounds like the old Vire engine, made if I remember rightly by Valmet Oy. It originally appeared in a 6hp version which was then uprated (and restyled) to 7 and 12hp. In the 60's, when Stuart Turner 2 strokes were the norm, Valmets little Vire was a welcome step forward in weight, size and reliability, and many production boats were fitted with them as a standard alternative to diesel which was then much heavier and smellier, and inclined to make the crew see double when running. They still remain one of the lightest engines around, but being 2 strokes, they are plagued by all the problems associated with the breed, including the need to mix oil/petrol, fouled spark plugs etc.

As you have already discovered they are very sensitive to exhaust back pressure, and many were scrapped because the rubber exhaust hose inner lining breaks down if there is a coolant shortage, and intermittent blockages would cause the engine to die - usually at the most inconvenient moment. It would always start again immediately, and run on until another piece of rubber blocked the pipe... This is easily checke

 

[oldharry]

This sounds like the old Vire engine, made if I remember rightly by Valmet Oy. It originally appeared in a 6hp version which was then uprated (and restyled) to 7 and 12hp. In the 60's, when Stuart Turner 2 strokes were the norm, Valmets little Vire was a welcome step forward in weight, size and reliability, and many production boats were fitted with them as a standard alternative to diesel which was then much heavier and smellier, and inclined to make the crew see double when running. They still remain one of the lightest engines around, but being 2 strokes, they are plagued by all the problems associated with the breed, including the need to mix oil/petrol, fouled spark plugs etc.

As you have already discovered they are very sensitive to exhaust back pressure, and many were scrapped because the rubber exhaust hose inner lining breaks down if there is a coolant shortage, and intermittent blockages would cause the engine to die - usually at the most inconvenient moment. It would always start again immediately, and run on until another piece of rubber blocked the pipe... This is easily checked by examining the inside of the ruber pipe at the manifold end - if it has wrinkles and folds in it it is breaking down and will soon stop the engine.

Parts used to be available from Fairways in Maldon, Essex - but that info is well out of date?

 

[toad]

Fairways at Maldon still sell new engines and spares.PBO did a good write up about six years ago,search under vire.

 

[barryg]

go to http://gofree.indigo.ie/~vire7/ this site will give you all the technical info you require plus on line workshop manuel.

 

[Guest]

Thanks very much for all the useful information.
Julian

 

[Guest]

I have just installed a Vire 7 in our 24ft yacht. Having a few teething problems after its rebuild....

Hows yours running at the moment?

 

[Guest]

Sorry about the delayed response - had not checked my mail for a while.

We also rebuilt ours and had a lot of trouble initially, because we had too much exhaust backpressure - this meant that the engine would run, then inexplicably die, and was very hard to start. With this sorted, it now runs pretty well. It is a solid little engine and simple to fix so it should really be a good machine.

What problems have you had?

Julian