Tim S do you or any one else know if there is a gear drive starter or any other starter that will fit on a 4010, LP that will spin the engine faster than the original starter? why will a diesel engine spin so much faster than my LP? I know the starter is larger on the diesel. I have the same batteries on the LP that I have on the diesel and the LP turns over at half the speed or less. I have owned this tractor for over 30 years and the starter has been overhauled at least 3 times.I have put 2 kits in the vaporizer during this time also.It now has electronic ign,new plugs,wires and coil.motor needs overhauled uses a little oil and low on compression on a couple of cylinders.this thing is almost impossible to start when temp is below 50 degrees.it was not always that way. I am thinking of installing a diesel engine instead of overhauling this engine. I know you have the information on which engine out of a combine will work and I guess I need to find out which one will work the best. there are farm sales in my area that sells 6600 and 7700 combines ever now and then. thanks for any help you could give me on the starting issue until I decide on a over haul or engine change.