Backfiring through carb

[Cogita]

Hi guys

I have a 1200cc motor which had been running great for a while, it eventually started jerking badly and backfiring through the carburettor, sometimes flames, it now struggles to keep an idle, its a 30 pict carb.

So basically, when I pull away bug would hold back ,sputter a lot and give a lot of tiny backfires, then it would drive fine until I reach a speed bump or stop sign, then the the sputtering and backfiring will repeat.

any advice?

Regards
Roscoe

[Haans]

Me thinks it could be over fueling,.....haans's carb has a electric shut off valve,..and tthe wire came of a while ago rendering it close to un drivable, snorting farting and baulking !
i eagerly awaiting the ghuru's feedback on this one
Regards Haans

[73type2]

Make sure that your carb’s accelerator pump is working as it should. There should be no leaks with mating surfaces flat. Warping is common with over tightening 50 year old parts. A broad file can be used to get surfaces flat again. I suffered the symptoms you mention and found wetness under the accelerator pump area.

Just an aside, 28Pict is normally used on a 1200, with 30Pict2 on 1300/1500.

[Dawie]

You can also check valve clearances and do a compression test.