Posted by Fats on January 25, 2000 at 17:02:15:
In Reply to: Re: Backfiring posted by Christine Knowles on January 25, 2000 at 11:04:28:
Your points are well taken - and yes, backfires can occur both through the carb side or through the exhaust side- outcomes are the same though - back pressure where it shouldn't be.
Carb slides are vulnerable also.
Closing the throttle doesn't lower the compression ratio as this is a mathmatical formula of the ratio of the piston swept area inside the cylinder. It does however lower the pressure because there is less volume of material- specifically gasoline - sucked into the cylinder on the intake stroke
Years ago - a friend rode an NSU Super Max (my age is showing) which had a mechanical decompressor- the muffler had been cut away to decrease back pressure - at highway speed we used to pull the decompressor - to fill the muffler with hot fuel - then drop the decompressor valve closed and bang a flame would shoot out the end of the muffler when the gasses ignited- great fun! but still hard on the valve train and in that case especially on a tiny decompressor valve
Appreciate your comments on the nature of backfiring
Keep the rubber side down
Fats