Backfiring

[Rick Hamilton]

After a long winter in a dry garage my 1953 Oval (with later 1192 engine) has started to backfire on the overrun. It could be due to all sorts of things, such as an air leak in the exhaust, but is there a more common reason for this ?

[ZENVWDRIVER]

... not timed properly.
... need valves adjusted

I'd do a tuneup and check the compression
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[Rick Hamilton]

Thanks for your help. Can timing slip on its own? Being a bit of a dummy here but I wonder what goes wrong while sitting in the garage !

[janerick3]

Lubricating the distributor counterweights with WD-40 (or similar product)will cause backfiring later, as it gums up and the weights don't retract quickly enough.
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Thanks,
Jan K.

[JPB1]

Fuel supply - check filters (one in the tank and under it), engine maybe starving itself of fuel and misfiring.

[0nebadbug]

Sounds silly but... Any evidence of any rodents moving in or passing thru?

Check all of your wires as well as plug wires... not just visually but also for resistance...

2 years ago I had a really weird backfire & bog issue when pulling it out from winter hibernation. One minute it would be fine & the next the smell of fuel & wheezy backfire, felt like the chokes butterfly was slamming shut, load up on fuel & pop.... As soon as I got home, checked choke and was fine, pulled the carb, fully cleaned it and then redid timing 1/2 a dozen times, checked the plugs, squeaky clean, changed fuel filter, triple checked valves & adjusted them anyway and then pretty much everything under the sun you can think of mechanically and it still persisted...

From there I started thinking electric, maybe ignition switch or along those lines... so I randomly started poking everything with a voltmeter checking resistance and while every switch, terminal tight, contacts, fuses & every other wire in the car checked fine, In the very end I accidentally found that 2 of the brand spanking new plug wires (which I put in 4 months prior) tested bad with resistance, so I figured maybe I just got a bad set so, I ordered up another new set...

The following weekend when the new ones arrived from WW, I pulled the old ones out and as soon as I flipped the 2 bad ones over I found the culprit... they had both been gnawed on from the underside and the only way of seeing where they gnawed was by pulling them out as you could not see where the chewed them from the topside. And where they gnawed them was exactly where they both exited the steel wire loom and when I would drive the car, the vibration would make cylinder 2 & 4 crossfire when one of the gnawed wires would make contact with steel loom...

Sneaky little bastards...

EDIT... Ha... Post # 1,000... Where do I send in for my free gift?
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