Effects of humidity?

[Tri-Motor]

Does humidity have an effect on the way an engine runs? I've noticed with my Yamaha YT125 on humid days that the idle is lower and the engine feels a bit boggy. Usually when I'm cruising down a trail in 5th gear about 1/2 throttle I can see a faint smoke haze behind me, but on humid days I can actually see a trail and power is noticeably lower above half throttle. On non humid days it idles great and has plenty of power. Thanks

[MattDragontamer]

You may need to make your fuel mix a little richer.

[Flyingw]

To some degree yes, humidity does effect performance. When the air is dry and hot, the air is lighter than when its cool and humid.

[Tri-Motor]

The tiny bit of info I could find said humid air makes an engine run rich

[wonderboy]

More humid = more moisture = less oxygen (if everything else remains equal). So, if you engine is getting less oxygen, it is running richer.

Hot, humid, high elevation all make an engine run richer.

[Scootertrash]

Does humidity have an effect on the way an engine runs? I've noticed with my Yamaha YT125 on humid days that the idle is lower and the engine feels a bit boggy. Usually when I'm cruising down a trail in 5th gear about 1/2 throttle I can see a faint smoke haze behind me, but on humid days I can actually see a trail and power is noticeably lower above half throttle. On non humid days it idles great and has plenty of power.

Thanks

Has your carb been properly tuned on an average day for your area? Valves adjusted properly? If your engine is tuned properly I'm not sure that you'd notice that much of a difference in how it runs on a humid day. I've never really notice it. Now, if you travel to a different elevation that would be a totally different thing.

[Tri-Motor]

This is a 2-Stroke. I'm running completely stock 200 main jet/25 pilot jet with a fresh air filter

[El Camexican]

If you're jetting is stock and power is dropping off noticeably with a slight change in air density you may be due for a set of rings.

[Scootertrash]

This is a 2-Stroke. I'm running completely stock 200 main jet/25 pilot jet with a fresh air filter

It doesn't matter what you arwe running for jets, has it been properly tuned? As in have you run thru the carb tuning process?

Read this, don't just browse thru it quickly, read it and absorb the knowledge ;):

http://www.3wheelerworld.com/showthread.php/55086-Carb-Jetting-101-Terms-Tips-and-Jetting-Theory

[onformula1]

Because I type very slow, I stole this from Eric Gorr its a good read 5 pages total, I skipped ahead to the humidity part.

I always carry with me a- Barometer, humidity and temperature gauge with me when I go riding...Along with a complete jet kit.

http://dirtrider.net/forums3/threads/carb-tuning-page-5-by-eric-gorr.184621/