Thread: Help...2L engine backfire with flame and power loss

Very strange behaviour but with the backfiring, I'd be looking at timing first up.

the fact it went okay for a while then let go sort of lends itself to ignition component breakdown, would be my first pick

coil, condensor and or wiring to same etc etc

Remember 80% of all fuel problems will be ignition,
1. Is the plate that the points are screwed to tight at its 2 mounting screws.
2. Adjust point gap while holding shaft away from the point to make up for play.
3. Replace points with known good pair, not new pair.
4. Check timing with light or static.
5. PM me for a talk.
6. Replace plugs.
Dennis

Hi Mark

My first thoughts are; is the coil the correct 12 volt / or good healthy one as it maybe breaking down when it warms up?

The next thing to check is the points, look and see if they haven't come loose both in themselves or the advance retard plate they are fastened to, if that plate was stuck when the timing was done, the plate could have freed up it's movement throwing the timing setting out.

That advance retard plate should have a fine braided earth wire between the plate and the body of the distributor, make sure it isn't loose or broken as any other current path to earth from the distributor points can cause erratic results.

The last thing electrically to check is the condenser, best way to check that, is to change it with a known working one.

Drain the carby and watch for any water or dirt, a bottle of methylated spirits in the tank is a crude way of getting rid of a small amount of water in the petrol, flush the carby out and blow it clean with compressed air should sort any problems there.

.

Oh yes there is something else, the ignition switch !
Don't have any weight on the key as when it swings the contacts in the switch can move upsetting the power to the coil.

The cure is a new switch and then you can go back to hanging your rabbits foot on the key.

Mark

While the engine is turned off.... Remove the air cleaner inlet from the top of the carby and look down into the carby ..... as you move the throttle up/down, look for a squirt of petrol from the accelerator pump , it should squirt a stream of petrol down the throat of the carby

Sounds like it isn't working .

It could be one of many things that can go wrong

Mike

no start at all now........
1/replaced leads with narva 7mm copper core and checked with multimeter.
2/ new capacitor{ill change back to ol new one that started the car thismorning after disaster run}
3/clened and gapped points .15
4/ set points gap at 10 btdc mark ,rotor pointing at c1 lead post on leading edge while pressing diz shaft
5/ new plugs{equiv of champion n21} gapped .30
6/tightened all elec bolts from dynamo coil etc
7/ stuff of key

not a thing, no sign of firing
going to pop out and drain carbie and put old coil back in and look at carb with intake hose of then douse it in petrol and walk away{damd power line over top of car.....one of those days...

change condensor back and looked at banjo bolt & filter{spotless}
car runsagain but 400 meters and it dies...
had a look down carb with petrol pump running and a trickle of fuel squirts out when throttle levers worked...
coil is hand warm.....
theres a unknown white body'd lucas coil that came with engine, perhaps its ok but i dought it
ill look at the spark when it gets dark and sort that oil leak and try the other coil