Diagnosing a Cold Starter
 

2004 XL1200R. Starter always struggles to turn engine past compression stroke. Cold weather makes it impossible. Bad battery? I hooked two weak batteries in parallel and motor turned like it was new. Ordered a new battery, installed it today. Started bogged down again, but air temp was 50-ish. Hooked trickle charger to new battery. Got green light after 3 hrs, hit the start button and failed to turn over past compression stroke (temp this time was 30-ish).

Bad starter?

Bad something!

Have you checked the battery ground connection to the frame?