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Technical / Whats wrong ?
« on: October 05, 2011, 01:54:40 PM »
OK experts.
Recently I had a Yamaha 50Hp outboard in for tune up. 3 cylinder.
Compresson test motor , replace spark plugs , test spark.
Striped and cleaned carbs x 3. (Yamaha keihin carbs are known to block emmulsion tubes if run on dirty fuel.)
Reassemble and test run.Balance carbs and adjust idle mixture.
Motor idles perfect but when revs are increased motor runs on 2-2.5 cylinders.
Check fuel flow out of carb with timming light & torch. No. 2 carb running lean at part throttle.Motor runs good above 5k rpm.
Remove carbs.Strip & inspect.All seams fine.
Inspect reeds.Fine.
Reassemble and test run. Same problem.
Motor idles perfect & runs at WOT perfect. Not in between.
Whats wrong?.
Yes I found the problem.
Recently I had a Yamaha 50Hp outboard in for tune up. 3 cylinder.
Compresson test motor , replace spark plugs , test spark.
Striped and cleaned carbs x 3. (Yamaha keihin carbs are known to block emmulsion tubes if run on dirty fuel.)
Reassemble and test run.Balance carbs and adjust idle mixture.
Motor idles perfect but when revs are increased motor runs on 2-2.5 cylinders.
Check fuel flow out of carb with timming light & torch. No. 2 carb running lean at part throttle.Motor runs good above 5k rpm.
Remove carbs.Strip & inspect.All seams fine.
Inspect reeds.Fine.
Reassemble and test run. Same problem.
Motor idles perfect & runs at WOT perfect. Not in between.
Whats wrong?.
Yes I found the problem.
