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Mini backfiring badly


SP450andLE

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Trying to get my Mini running, but we have hit a bit of a wall. It keeps backfiring really badly, and if you put your foot down it'll just pop and bang loudly and not really do anything, just puff black smoke and start to die.

Vid of what it does:

th_MOV02995.jpg

EDIT: It has new points, condensor, rotor, dizzy cap, coil and leads (although the leads are from the Lada :? )

We have done the timing, points gap etc, but it still runs badly.

Any ideas at all would be appreciated.

Chur.

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Spark is average.

Lincooln (mah broski) had a play around with it after I left for band, and he figured out the new rotor didn't protrude out far enough, so wasn't contacting with the dizzy cap well enough, so was making spark pretty weak at times.

He also kept on making it richer, and he managed to get it to a driveable state, just needs some more tweaking (mixture and mebbeh timing) and brake bleeding before it is ready to take it to get a WoF.

Hopefully it passes, will me a miracle tbh, considering it had no engine at the start of the week. Not even until tuesday evening :lol:

Chur for the suggestions so far :D

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Looks pretty rich...

Setting dwell amounts to the same thing as making sure your points gap is right. Makes sure current flows through your coil for long enough to establish a nice big fat magnetic field, so when the points open, the current stops, and the field collapses, you get a nice big fat meaty spark :-)

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Would pay to recheck tappets, then try running it bit leaner if you have good fresh fuel in it.

Also check dizzy is advancing, i normally just mark the crank pulley at 11mm increments as a rough 10 degrees and watch it climb with the timing light as you rev it.

EDIT:

Do you have a good solid earthing lead for the engine, and also have you checked to ensure you have the +ve and -ve wires the right way on the coil.

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Setting dwell amounts to the same thing as making sure your points gap is right. Makes sure current flows through your coil for long enough to establish a nice big fat magnetic field, so when the points open, the current stops, and the field collapses, you get a nice big fat meaty spark :-)

This but dwell is the most accurate way of setting point gap. If the points have been run at all then they will have small highs and lows on the breaker surface and unless you file them perfectly smooth then feeler blades are not going to measure that gap accurately (remember we are talking about a difference of 0.125mm would be massive!)

It takes a little bit of messing around to set it right but IMO is worth it.

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Gah, this is so stupid.

We started the thing thismorning, it ran OK, but the just stalled. No spluttering or anything, just stalled as if someone had turned the key off.

We have tested it, and there's no spark, but there is power at the coil. We have tried 2 different sets of points & condensors, 2 different dizzy caps and different leads.

The points on it before (brand new ones) looked like they were burnt on one contact point, but replacing them hasn't helped (and yes, we gapped them correctly).

And what's more, the guys from the garage still haven't turned up :evil:

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