ST16- new head, carb rebuild, now starter is making god awful noises and won't stay running unless full throttle. Bought her in "working" condition, but missing a carb needle (ha, ha Ha). Ordered parts, had a friend put together, then needed new gasket set (exhaust leaks) new head (exhaust port stripped beyornd) and NOW still doesn't run well. Hard, almost painful start-runs at high but no middle. Possible coat hanger throttle linkage??? Running out of time before she's supposed to pull a bunch of ol'lady dogs in a Howl'oween parade... HELP ME PLEASE.