600\660 issue

[Greasemonkey]

Lost a engine in 2016 switchback 600 w\2500 miles. PTO rod bearing failed. Unsure why, all oil lines ok. Got a good deal on 660 big bore and did the swap. Engine runs great but I hear a pop from the exhaust at idle, ok above idle speed (1600 rpm). I checked and adjusted TPS to spec using PCV for voltage value. Any thoughts. Idle fuel mapping is stock, plugs look good besides a little rich due to 50:1 oil mixture.

 

[racerdave]

I would say that 660 needs 10% more fuel throughout. Based on old 660 carb needs. Just a quess.

 

[Greasemonkey]

 

[big tom]

Who's kit did you go with?.

 

[Greasemonkey]

Who's kit did you go with?.

It was built by Ean @ koolmekustoms