Runs Well, Can’t Reach Top Speed??

[99yam40]

so are you trying to say full retarded spec is not with throttle at idle?

 

[jimmbo]

What I am saying, is that on every 2 stroke I have ever seen, the Carb(s) are fully closed at Idle, and the Idle Speed is controlled strictly by the Spark Advance/Retardation. A change in Prop Pitch will load an Engine differently, and will affect where the Timing is, to attain the correct in Gear, Idle Rpm

 

[99yam40]

on all 2 stroke motors I have ever worked on ,outboard, chaisaw, weedeater etc there is a idle speed adustment srcew that cracks open the throttle plates to set the idle speed.
just like on my C40TLRX shown in the pic I posted there is a spec for timing while at idle, and you do not change the timing to set the idle speed, you adjust the idle speed screw on the carbs

 

[jimmbo]

on all 2 stroke motors I have ever worked on ,outboard, chaisaw, weedeater etc there is a idle speed adustment srcew that cracks open the throttle plates to set the idle speed.
just like on my C40TLRX shown in the pic I posted there is a spec for timing while at idle, and you do not change the timing to set the idle speed, you adjust the idle speed screw on the carbs

No 2 Stroke Outboard I have ever seen the past 60+yrs has ever had an Idle Speed Adjustment done at the Carb.

 

[99yam40]

apparently, you have never worked on Yamahas.
maybe the old johnyruds is what you are talking about moving the timing plate.but those were way back 30 or40 years ago