Cranking Then a Hard Stop...Then Cranks

[jg61hawk]

This started about a month ago....I crank it over with electric start and the motor is turning but suddenly it almost freezes with a hard "stop" but then continues to crank . This may happen once or several times before it starts.

I thought the battery may have been losing it's cranking amps as it was 6 years old, so I got a new dry cell 6 volt. Still doing it. I'm thinking I'll reset timing, but why would timing just fade away? Yes the spark is retarded on starting.

Thoughts

Thanks Jim