Engine needs half crank to start

[mcfish]

My 1 year old Craftsman 26 HP starts readily if I jump it. If I cold crank it, it tries to turn over but won't go all the way through. If I manually turn the meshed exposed head around a half turn or less, then use the key it usually starts up. This can occur even after it's been running a while.

Yesterday I ran out of gas. I accidentally added chainsaw fuel, mixed gas/oil, rather than straight gas. This is probably 6 month old fuel. Now even the manual rotation of the head doesn't work. Any thoughts? Should I get a charger? If I can jump it to start it, can I just burn through the gas/oil? Or should I try to change fuel before jumping? Thanks, a newbie.

 

[SeniorCitizen]

Take the battery to an automotive supply that will load test the battery and sells lawn mower batteries. If it tests OK and the battery cable connections and battery posts are clean and shine adjust the engine valves. If the battery tests bad and a new battery does the same adjust the valves. If you purchase a new battery be sure they sell you one with the same configuration pertaining to + and - arrangement as your old battery.

 

[motoman]

A $3 battery hydrometer and good smart bat charger. The mag coils need ?250 rpm to develop decent starting voltage. Sounds like that may be part of the problem.

 

[mcfish]

Thanks fore the help. Got a charger and low and behold, battery is only half charged. 4 hours charging and a jump got it going good. Used 5-6 times since and it starts every time. Trickle charge the night before planned use and it should be good even after several months of sitting.