larger engine, original muffler, problem?

[Anonymous]

After going to a new dual port 1600 on '70 Westy, problem are occuring. After warmup and when going uphill it will begin backfiring and losing power. Also, will be hard to start , like starter dragging. Could this be a result of the original muffler. The car had been sitting for 6 years. Everything in engine is new. but the muffler is the one that was on the engine. What other problems would a resticted exhaust cause?<br>help,<br>dennis

[Red Baron]

My thought is something other than the muffler.  My first thought it bad generator.  Not putting out enough or any power and the battery is drained.  <br> <br>Its starts up good cold? <br>Then it runs poorly when its warmed up?   <br><br>I plugged muffler would make it run poor all the time.  Almost sounds like weak spark or fuel pump issues.  Those engines are so simple.  If you have spark and fuel, all things being equal, it should run.  Maybe the points are burned, or the condensor isn't doing its thing.  Maybe the coil it tired.  Electrical compents don't like heat.  

[Anonymous]

Thanks for the reply, I don't think we have checked the fuel pump. The others we have. Actually it cranks well and runs well until we start up the first hill or put it under strain. My mechanic has rebuilt over two hundred VW engines and says he has never been as baffled as he is now. He has switched distributors, coils, wires and carburators as well as checking the coil to distributor wire.<br>Thanks again,<br>Dennis<br>Cedartown, GA