ShopTalk Forums | Aircooled VW Tech & Restoration Help

lalalalala

Got dual carbs? If yes, common problem is carbs out of sync, bent throttle stops, linkeage bent, etc.,.....
Mine would pop after hittin the throttle hard and screetchin' the tires.
Took me a long time to figure out.
Maybe you have the same problem.
Spend some time on the carbs.
Aircooled.net has a great "how to sync" tech article.

Pete S

dual carbs yes.had a shop sync the carbs and set timing suggested placing the stock points instead of petronix.I done exactly what they done but wanted to cover my ass since it was my first dual sync and the problem started before I touched the carbs..

blocked or too small idle jets. or a hole/leak in your exhaust.

see if you can get one of those spark plugs that have a glass rather than ceramic top that allows you to see the colour of the flame in the cylinder. Once carbs are balanced adjust idle mixture screw until the flame turns yellow then turn it back till it turns bunsen burner blue. do this on each cylinder and all will be well.

wind air bypass screws out a bit if you can't get a nice blue flame

They are called a Colour Tune here in the uk but are sold under licence from a US firm.

mail me and i'll have a look in the shed for the box and the maker.

nice cheap and usful bit of kit for the twin carb user. approx $20

Petrinix should be fine only problem Ive ever had with mine was the magnet asssembly falling to bits when it was removed in a hurry. (replaced damn quick under wrranty)

Dave

If it pops back through the carbs, it's too lean.

If it's backfiring through the exhaust, it's either too rich or there is an exhaust leak.

Good luck.