Posted by gmharris [72.219.148.98] on Saturday, September 13, 2014 at 00:52:33 :
In Reply to: Re: strong spark it seems posted by Bob Perry [107.5.248.120] on Friday, September 12, 2014 at 19:36:54 :
If you've got good compression, then valve timing and valve lash are in the ballpark.
If the engine fires at the wrong time, you have an ignition problem. Backfiring though the carburetor (more accurately spitting or coughing) is sometimes a sign of lean mixture or a carburetor problem.
Check for cross-firing between the spark plug cables and try adjusting mixture.