206 loss of power

Kart seems to be losing a bit of power down the straights. I was running at the mac track at padholder and the faster guys were just going a lot faster down the straights/esses and I know I was getting a good exit. I was also running the same gear ratio and the power was not there. I was running 44.9 avg when they were running 44.2 or 44.4s. But, this could also be a driver issue🤷

If you really think it’s engine related:

Clean the carb, especially your jets. You can lose more than a few tenths due to this.

Excessive leakdown may be a possible culprit, but I’d look at a dirt carb first.


I did forget to mention I was running really rich for some reason the weekend or atleast as I remember Sunday.

How do you know you were rich? You can’t tell by pulling the plug after a cool down lap. It will always look rich due to these carbs.


Black smoke was coming out of the carb. Also the spark plug was like a matte black lkke carbon buildup after 2 races

If you got smoke out of the carb, something else is wrong.

Intake valve to tight, burned intake valve… if thats the case leakdown will be horrible.

Thats the only thing I can think of…

Check valve lash, if excessive, probably a burnt /bent valve.

Air filter clogged or wet?
Float height?
Slide needle position?
Throttle cable and return spring seated properly?

Sorry I meant exhaust😅

So, air filter is fine, changed it the day it happened actually to a brand new one. Valve lash is about 0.003 of an inch (I’m both) and the needle position is 2. And yes the throttle cable and return spring are fine!

Okay will see! Thank you!

What’s the float height?
Just trying to check all the simple things first before unnecessarily pulling the head.