Dire Vire 6 problem

[DavidTocher]

The engine has always been a ready starter until recently. The
engine started to run very hot. I removed the cylinder and flushed
out flakes of rust from the waterways. I reassembled the engine
which started easily and ran cool.

The next day after 2 hours running the engine cut out as if the
ignition had failed. I checked the spark which was OK and replaced
the plug as a precaution. The engine restarted very reluctantly
and took time to build up revs and power. It then ran for about
another hour without any problems but had a reluctant restart.

I spotted a crack in the vacuum tube for the crankcase to
carburettor (operated the integral fuel pump)and replaced the
tube.

The following day it ran for 6 hours without problem but died on
idle when in a lock. I failed to restart the engine. The next day
it readily started from cold. The subsequent day it was reluctant
to start from cold or warm.The spark plug has always looked its
usual self i.e. black from all the oil (20:1) and I suspect the
grade of plug (L86), which I have always used, is running too cool
to keep it clean.

I did wonder about the ignition timing but the symptoms don't seem
to fit. Would a leaking cylinder/crankcase joint give me problems
like this? Any suggestions, other than replacing the engine, as to
the cure for my problem? Would an ultrasonic cleaning bath help to remove the rust?

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[jimkirby]

I cleaned the water jacket by getting it grit blasted/ Its amazing how much rust flake builds up.

i also found that old fuel can gel and choke the fuel line. With the tillotson carb you cant spot that.

My engine used to run for precisely 38 minutes!

In the end I mae up a new inlet pipe and replaced the tillotson with a scrap SU having contacted them about jet adjustment.
I then went the whole hog and fitted an SU petrol pump also from a mini. I got at least two more HP from the engine and solved the cut out problem.

At the least whip off your current carb and replace the diaphragm ( get one from you local lawnmower repairer! and make sure you keep the fuel fressh. Another trick is to get some Briggs and Stratton fuel freshener also from your lawnmower pals. This will stop the fuel gelling.

good Luck

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[Guest]

Common problem

Is rust build up and then 'grinding' away in the crankcase ..... finally you end up with lack of fuel draw ...... mine ended up having to be flooded to start and then dieing literally as soon as flooding was stopped.
New seals and bearings put the engine back into A1 - the guy who bought it from me did that !!!!


<hr width=100% size=1>Nigel ... and of course Yahoo groups :
http://groups.yahoo.com/group/gps-navigator/

 

[wells01]

Hi
A blocked fuel tank breather could cause the symptons you describe. If you have recently cleaned the water jacket you might have a blockage where the water is injected ito the exhaust, this will also give you problems. Its also worth changing the condensor as a matter of course, they dont like being left over winter much and get a bit flakey.
Regards
David Wells

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