Plug colour

[WD Forte]

Been taking my lovely scooter for a few shake down runs
and it went pretty good all in all
when it was fully warmed up I got some popping when shutting off
the throttle though
I checked and nipped up the exhaust header and whipped the plug out to see if was
OK and not quite sure, pic below.
I compared it with online pics and it not grossly out of whack
as far as I can see
A bit lean? OK?
Waddya reckon?

Mulling it over:
Two other issues which may be having an effect are

1- The tick over is a bit low and may be shutting it off too much when
closing the throttle?

2- The carb has a tps type pot on the spindle which sends a voltage to
the spark control unit to advance the spark when the throttle opens
It works, but when I tested it, the voltage output is a bit jumpy and not as smooth as it could be
which indicates a worn/dirty track.
New ones are £200 ish so sod that for a lark
https://imgur.com/osXU0Ws.jpg
____________________
bikers smell of wee

[Hong Kong Phooey]

Plug looks OK to me. If the pot is open (unlikely on a bike) then a good squirt of contact cleaner does wonders, dedicated sprays have a lube to keep things smooth.

You might be able to prize it open, clean and then reseal.

As for popping, as you indicated it might be an air leak in the exhaust, combine that with residual fuel and you go boom. People pay good money for that, so leave that feature alone.

You can disconnect the tps from the spindle to see if anything changes, and set it around the middle, or work out the min/max and rotation and fit a generic pot or one from another model maybe with an adjustment resistor in series if required.

As for idle speed, if it's too low then the genny/alternator won't put in enough charge at idle, especially with headlight on, I use the output voltage as a guide for setting mine. Doubt it's anything to do with the popping though.
____________________
'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[redeem ouzzer]

Touch lean but not massively so.

Hard to tell properly with modern fuel anyway.
____________________
Be a REAL MAN!

[WD Forte]

Thanks for the replies
Should have left it alone as its now got an intermittent non start fault!
Bollox!, It's always started so easily, what did i do?

I've stripped it and checking cleaning all electrical/ignition stuff
which won't hurt and is a good time to test the spare ignition control box I bought
so I know it's a working one.

Did I say £200 for that tps? try£400 !!! Ouch!
I've been testing it again and luckily it's not as bad as I thought
On closer inspection the gaps/notches I assumed to be bad tracks were down to my digital meter
changing resolution from 3 to 2 decimal points as the voltage rose.
A test using an analogue meter showed it smoothly sweeping up and down with no drop out or spikes

After all this fart assing about I eventually remember it has a non standard exhaust
which was straight through until a I cobbled a db killer of sorts and its still a bit 'throaty'
so the popping back could just be down to that.

It probably wasn't broke and I didnt really need to fix it
Ho Hum....
____________________
bikers smell of wee