[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]
----- Original Message ----- From: "Greg Merritt" <gregm@vwtype3.org> > So, er, not that I know that much about carbs, and even less about > stock Type III carbs, but could there be some way you've started running > really rich, or dumping gas into the intake from the carbs after you stop? Thanks Greg, something to check but she's running so well otherwise that I don't think it can be a carb problem unless its the pilot valves not shutting off the carbs properly? will have a look today. I wish I could see a fun side but Its so loud I'm sure it could do some permanent damage ;-( > Steven Ayres wrote: > At the risk of becoming tedious I must again distinguish between explosion > through the intake (backfire) and explosion in the exhaust (postignition). > You didn't mention that your your air cleaner blew off, so this sounds like > postignition or a sticky exhaust valve. Someone else has already pointed to > the possibility of fuel buildup in the exhaust. If it's loud enough to scare > the neighbors, however, and it only happens once in a while, it's probably a > good idea to take a look at your valve guides. With the right combination of > wear and low lubrication a valve stem can bind, allowing fire out the valve. I haven't looked under the cover yet! Think I should- I hope I don't find mangled aircleaner and shredded carbs! I guess I've been suspecting a valve not working consistently for a while now- could help explain some of the strange unGerman inconsistency I've been experiencing for ages. The bang is so loud that I think it must be a very good mix of fuel and air so I'm not sure a carb leak can be to blame- that would be too rich wouldn't it? > Dave wrote: > I restarted at Stanford Hall VW show a few minutes after stopping, to reposition > the car a bit, and got a backfire that blew the plug of sealer paste from the > muffler hole. Thanks Dave, - dunno why you're sealing up your muffler hole though- thats taking cal-look to the extreme isn't it ;-) >I suspect you may have a small exhaust leak and unburnt mixture > from starting ignited in the muffler. I think I need to give my valve train the thorough looking at that I had promised it a while back- the reason I had not looked then was that the running seemed to be healing itself- getting better each week and I decided to let the car get on with it- it often seems to get a bit funny about me fiddling too much. Thanks all, Mark Seaton, '73 Fasty ------------------------------------------------------------------- List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org