VIRE 6

[Martind]

I have a problem with the Vire 6 petrol inboard in my Trident 24 which is baffling me.
The engine was running perfectly for 4 hours, it was stopped and restarted 10 minutes later. It ran for a couple of minutes and cut out. It has not started since.
1) there is a spark although not the best I've seen.
2) when turned over and plug removed soaked through and will not spark.

The Carb has been stripped and cleaned, replaced diaphragm.
Points cleaned and gap checked.

Sprayed WD40 straight through CARB and turned over but no fireing, however bubbles could be seen at the base of the cylinder block indicating a leak of some type.

Any suggestions and comments would be appreciated


Martin


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[ex-Gladys]

If the plug's wet (and smelling of petrol) it has either to be ignition or compression. You say spark is not good, I'd start there. Check points, replace condensor, check plug caps and leads...

Do you have compression?

<hr width=100% size=1>Larry Botheras

Anderson 26 "Amber"

 

[martinb]

Because the plug is wet when removed it is probably a weak spark or flooding.
Does the 6 have a conventional carb or is it the tillotson type as fitted to the 7?
If it is the conventional carb (I think it is) check the float/needle valve arrangment to make sure that it is working correctly. I would suspect flooding first, as you have a spark.

Martin

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[Guest]

Having had the joy of a Vire 6 before - I had the same problem..... except no bubbling at crankcase - so can't answer that one.

The first thing I did was to wire in a Austin Mini Car Ignition coil to beef up the spark ! I found that the slightest bit of damp or start to flood engine and spark just was not enough to fire her ......

As to the bubbling ..... sounds like a seal has gone on the joint ?

The Vire is a simple engine and really shouldn't be too much to get going. Simple carb, no valves etc.

Eventually mine only started on full throttle and flooding ..... which meant - as the engineer told me - worn out seals on the crankcase stopping it drawing the fuel. I sold the engine on to a guy for his dory ------ he bought pattern seals and cleaned her up and it still goes now - 10 years after I sold it !!! Still I must add with the same Mini Coil I put on it !!

It pushed my Snapdragon 23 along at a good rate !


<hr width=100% size=1>Nigel ...
Bilge Keelers get up further ! I came - cos they said was FREE Guinness !
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[bob26]

Vire Owners website covers the Vire 6 - but not as much as Vire 7

http://gofree.indigo.ie/~vire7/home.htm

The Trident Owners Association manual has several pages on Vire problems.

See:

http://www.trident-owners-association.co.uk/

The most common Vire 6 problem is due to the engine water jacket silting up at the bottom (in vicinity of carb) causing overheating and carburation problems. But this doesn't sound like that.

Fairways at Maldon were always helpful to me when I had a Vire down below. They still rebuild them I understand.

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[oldharry]

Bubbling at the base of the cylinder block of a Vire indicates a crankcase compression fault. This will always make a 2 stroke difficult or impossible to start, as the crankcase compression is what forces the mixture in to the combustion chamber, expelling the exhaust gases. This is criticial to starting and running. Many perfectly good 2 strokes have been scrapped due to undiagnosed crankcase compression faults.

On the Vire 6 the blaock and cylinder head are cast as one, and from (long ago) memory, was held on to the crankcase by 4 studs. Try re-tightening the nuts, and you might just be lucky!

If there is still a leak, release the 4 studs, and lift the cylinder barrel clear. Unless you have a new gasket from Fairways at Maldon to fit, there is no need to lift it off the piston.

If the paper gasket is intact, coat it with Blue Hylomar gasket sealant, and reseat the barrel, tightening everything down securely. Make sure nothing drops into the crankcase while you are doing this.

If the gasket is not intact, you could probably 'repair' it using a silicon type Instant Gasket compound, but this is not a particularly good idea in such a key seal.

Otherwise do the job properly and get a new gasket, lift the barrel off the piston (requires a second pair of hands to catch the piston to stop it falling against anything as it comes free. Replacing it, make sure the piston ring gaps are at 120 degrees to each other. Again its a 2 man job to insert the rings into the barrel. Otherwise its all very straightforward.


Another very cpommon fault with these engines occurs when there is a coolant failure. the rubber exhaust hose internal liner over heats and bubbles up choking off the exhaust pipe, very effectively blocking it. This stops the engine dead every time. Pull the exhaust hose off the exhaust manifold, and check the internal condition - it should be fairly smooth. Any overheat damage will be immeidately obvious. Many Vires have been scrapped as 'unreliable' following this fault.

If still no luck, check that the igntion timing has not slipped. The flywheel operates the magneto contact breaker, and is keyed to the crankshaft. If the flywheel comes loose (which they do fairly easily) they can chew up the key, then slip on the crankshaft throwing the ignition timing completely adrift.

Good luck!

















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[Martind]

Thanks for all your advice. I have lifted my boat out now and intend to remove the engine and overhaul during the winter.It does look like the problem is to do with the crankcase compression.
Thanks again

Martin

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