running too lean. piston head light grey.

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Damian84

New Member
Sep 24, 2012
10
0
0
morgantown wv
hello,

past break in period of 24:1. was running cns carb, ran ok for a while, then lost wot speed, maybe 4 stroking and running too rich. could not get right settings with cns. so... replaced it with NT. ran great for about 15 miles on and off. then lost wot speed. Settings for NTwere :

c-clip on lowest notch, idle was ok, maybe a little high, but not out of control. 32-40:1 ratio. tank filter and inline are clean of debris, good fuel delivery.

when i came to a stop at my house from the ride where i lost wot speed i pulled in the clutch lever and she started idling really high and the kill switch did not work anymore. so slowly released the clutch lever out and she died out.

upon letting her cool down, cause whe was blazing hot ( spark plug cap looked like it was smoking a little bit), i pulled the spark plug (NGK BPMR6A) and the cylinder head. spark plug porcelain was tan to light brown and threads had white residue. the top of the piston also has light grey color to it.

this makes me think too lean..... c-clip is at lowest notch. running high comp head from pirate cycles. but ran great for about 15-20 miles.

Maybe richen up the mix again?

I'm flabergasted at this moment!

Other than praying to the 2 stroke gods... I look to this website and the professionals who know more than I.


-D-
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
Sounds like you might have an air leak somewhere causing a lean condition.
Ditto: Check that carburetor to intake seal and the intake manifold gasket.

Keep in mind that the needle clip position has no effect at WOT. Anything above about 3/4 throttle and the main jet orifice size determines fuel to air ratio. The needle is by that time out of the equation.

Tom