The "Standard Tuning" of a 2 Stroke Idle

[Jason2tpa]

Those of you who play a musical instrument will understand the double meaning of "standard tuning", as it relates to carb tuning a 2 stroke. Even those of you who do not play an instrument, you know when an instrument is out of tune. You may not know if the note is flat or sharp, but you know it doesn't sound right.

Likewise, in order for the 2 stroke engine to sound in tune, various systems must also be in tune. I can tell you with certainty when a guitar string is out of tune, 12 years of playing music. But with only 2 years of owning/fixing 2 strokes, my ears aren't as experienced.

Keeping with the same analogy, I can't tell you if the engine sound is flat or sharp, but I can tell you it doesn't "in tune". I'm hearing a very small amount of a rising/falling sound. I would expect a normal exhaust sound to be linear, a consistent grumbling.

If you have good external speakers, click on the youtube link below and take a listen. And if you have super keen eyes you might notice the engine faintly shake during this rising/falling moment.

https://youtu.be/npZ-Omxr8yQ

RPMs during this video bounce between 700-800 (tach only reads increments of 100). Engine info below.

[pstephens46]

Dumb question. Does it act any different in water at dock?

[Jason2tpa]

No, it doesn't act any different. But as you know, you can hear the engines exhaust on flush. The engine is running strong, really. But Im a bit of a perfectionist, thus rightly so want to engine fine tuned properly. I might be picking for just a small adjustment, though long term if indeed it is out of tune it could lead to a bigger issue.

[robert graham]

That idle sounds fine to me....especially for a 2 stroke...

[panasonic]

Sounds good to me, rpm going up and down slightly. All two strokes idle a bit rough, they are not very efficient at low rpm, and want be spinning up fast to work smooth. "Don't try and fix what isn't broke"