Fire over my carburetor...

[castorlex]

Last day my 1991 GTL`s carburetor set on fire..fortunately with no consequences more than a blow bonnet and all hoses and wiring burnt..sad thing. The only antecedent was carburetor cleanning and adjust by my local garage man ....Any guesses about direct causes (I must say , wiring was perfect...)

thanks

 

[mr-reno-139]

hi castorlex
sad to hear of your fire hope you can repair the damage ok
now this is avery strange coincedence as this morning i had to go and look at simon from brightons F6 van to see the results of a similar under bonnet fire
i was going to post pics and ask what was best way of cleaning extinguisher powder from carb that is now full !!!

damage is not too bad but no obvious cause of fire also ??

if carb which was new!! is u/s may end up breaking van

 

[Steve Hennessey]

Was this van being used without the air filter? If so then a fire can occur in the carb if there are problems with timing. Came across this problem a lot when I was younger as I had motorbikes with manually advanced magneto ignitions and no air filters. I was always told that if a fire occurred in the carb to turn over the engine again as the induction would put out the fire. It always worked.

 

[angel]

As the fault was probably not electrical (short circuit), the causes may be either a backfire (mostly due to incorrect ignition timing) or fuel leaking from somewhere on the hot exhaust manifold that is directly below the carburettor.

 

[malcolm]

I've noticed a lot of Renault 4s running with the Renault 5 air filter that is not tall enough to fit the air filter housing. That would be equivalent to running with no air filter. Presumably that would happen on starting or stopping rather than running Steve?

 

[Steve Hennessey]

Malcolm, the key thing is that the air filter as a unit must be a snug and airtight fit on the carb. So if there is a small fire in the venturi then it's contained and will go out very quickly. Try to start the engine as the flames will be drawn into the combustion chamber. These small fires mainly occur when starting. I would suggest for safety reasons that anybody who is tuning up their engine with the air filter off has a CO2 extinguisher to hand just in case. I speak as someone who lost their eyebrows whilst leaning over the carb on a V4 Transit engine whilst I was playing around with the distributor!!

 

[mr-reno-139]

thanks for your thoughts , bit slow replying as pc playing up
yes you are correct the air filter was being held on with a bungee strap as the carb fitted is off 1108 r6 (solex) and it is not threaded to take the plate that would normally take air filter and limited time last month meant no time for engineering

when it drove to my workshop last time simon had been using van with no air filter at all( and if you look carefully in [pics you will see Su electric pump on inner wing ) i was not happy especially as there was no hose clip fitted to carb inlet !!!!! yes i did fit one
fuel line is charred but not burnt through so unlikely cause of fire perhaps pressure was too high for carb and flooded ??
hope fuly i can sort it out as simon is very attached to his van and needs it for work

apparrently simon tried to smother fire with jacket which caught light so he threw it away and set a rubbish bin alight as well as van

jeremey beadle (RIP) would of been impressed