Slow crank, no start 85 750.
Like I said I have an 85 750 I just bought not running. He was riding on the highway and it sputtered for 5 seconds and died. Guy said carbs were cleaned 800 miles ago and I've got paperwork to prove it, but I have a slow crank and I cant get the bike to turn over. So far I've checked fuel, seems to be getting fuel as all the spark plugs are wet, it is getting spark on every cylinder. I've bypassed the starter relay trying to jump it and tried traditional jump starting from a literally brand new car battery still cranks turtle slow. However, it will crank at a fairly normal speed with the spark plugs out. I cant figure this out any help is appreciated where do I start