45 replies to this topic

[Sam Walters]

He probably had a big cam.

My 1293 296sp cammed mini did it. Lots.

[Ivor Badger]

Leaking inlet manifold gasket in the system

[Magic jason]

cheers guys

[greenwheels]

I always understood that popping on deceleration was caused by not much fuel/air mixture because the throttle is closed, i.e. not much compression in the cylinders causing a slow burn coupled with a slightly retarded ignition allowing the last bit of burn escaping into the exhaust when the valve opens.

[Cerberus]

On our crossflow, when the mixture was a bit lean, it popped through the carbs at light throttle (which wasn't good).

When the mixture was rich, it popped like hell out the exhaust and spat flames on the overrun, right up untill it blew one of the exhaust gaskets out, then it was constantly popping all the time,


I think if everything is standard, and everything is working correctly, you'll probably struggle to get lots of pops and bangs, unless you put some stupid 3" exhaust on.

Mine pops a little bit if I'm revving it while sitting on the drive, but when I'm out driving, I can't hear any pops or anything due to the all of the other noise being so much louder.

Edited by Cerberus, 27 January 2012 - 11:06 AM.

[freshairmini]

I think the popping is from the overlap on a racy cam, Its caused by the unburnt fuel getting into the exhaust system and igniting.

Ideally you don't want it because it usually means you carb isn't set right or your exhaust has holes in it, basically you wont get any kind of good performance. Just save you money and get a nice cam, maybe you'll get some nice popping with that

[R1minimagic]

The old turbo rally cars were best with active boost control

[R1minimagic]

[liirge]

swear you can get lean pops thou?

Out of the Carburettor yes, out of the exhaust...no

[Magic jason]

Christ, that rally car sounds like its being followed but some kind of rapid fire shotgun! haha love anti lag!
Well thanks, understand it a load more now

[joel93]

mine does it quite a bit, singal box exhast and carbs runing a bit rich acording to the coulour tune think thats why it pops,
needs setting up properly fuels expensive but dont want to loose the rally pop and bang

[ANON]

you could just buy a bike...click the pic



it's better when it's being ridden at night, the flames can be quite impressive

[Cerberus]

Its amazing how something so awesome can be completely ridiculous at the same time,

[Cooperman]

Unless you are running with a really high-overlap cam your Mini should not backfire, or pop & bang. If it does it signifies an over-rich mixture. This, in turn, will klead to 'bore-wash' by the fuel and cause a high rate of bore wear leading to a premature need to re-bore and fit new pistons.

[Magic jason]

just from overfueling? wow :L