YS 63 - Carburation advice requested
 

Hello,

how many turns maximum should be unscrewed the idle screw?

I ask this to have a reference mark in order not to lean too much the engine when it idles.

From the starting point of 1 turn open I unscrewed the idle screw progressively untill a 3-1/2 turns, and the rpm still seems stable (according with the manual if the engine is lean at idle, rmp should increase). I don't want to exceed on leaning it.

Thank you

RE: YS 63 - Carburation advice requested
 

The engines will vary a little but 1turn to 2turns is normal. Is the engine running too rich at idle?

If its not running too rich then why would you insist on leaning it out more to get it to run worse?

Basically once you get open past about 2.5-3turns there will be no change as the air bleed hole is already open full. If the engine requires a leaner mixture then it needs to be done at the regulator. Turning the regulator screw CW will lean the pressure system and will affect idle mixture.

Caution too lean on the regulator can cause detonation and backfiring of the engine this can damage it.


Troy Newman
Team YS Performance

RE: YS 63 - Carburation advice requested
 

Thank you Troy.
I'm simply trying to obtain a good setting, and leaning the mixture on one hand the engine seems more powerful around idle (rpms are higher), but on the other hand I don't want run it too lean and never experienced the rmp increase explaned on YS manual, so I can't figure where is the limit and if I reached it.