Pit Bike Club

0187johnny1 · 15-04-2009, 08:00 PM

HI EVERYONE I HAVE GOT A THUMPSTAR PITBIKE WHICH HAS 2 PROBLEMS 1ST IS NOT RUNNING 100% AND THE SECOND WEN I REV THE BIKE IT KEEPS BACKFIRING !! I THINK IT IS SOMTHING TO DO WITH FUEL MIXTURE COZ I CLEAN THE SPARK PLUG PUT IT BACK IN THE BIKE STARTS IT UP THEN TAKE PLUG BACK OUT AND ITS BLACK AND SOOTY!! HOPE SOMONE CAN HELP?

mcglynn · 15-04-2009, 08:07 PM

your right, if your plugs sooty, then your misture is far too rich.
you'll need to adjust the mixture screw on your carb, which's area will depend on the brand of your carb, either a spring held screw on the side (VM) or underneath.

the plug should be sort of blacky browny, run too lean, and the bike won't run good (over heat).

Good luck.

EDIT:
In Future, try not to use caps ALL throughout your message, it gets annoying.

Toby_Thump · 15-04-2009, 08:11 PM

sounds good when they bac fire!! :P haha!! lol but... yeh idle screw ^^

evopitbike · 15-04-2009, 08:12 PM

Idle srew WTF no mixture srew .... back fire is normally jew to... too much fuel left over

_James_ · 15-04-2009, 08:26 PM

Mine sometimes back fires when the exhaust is loose

So I'd check that aswell.

mcglynn · 15-04-2009, 08:37 PM

Quote:

Originally Posted by evopitbike

Idle srew WTF no mixture srew .... back fire is normally jew to... too much fuel left over

chillax, and spell 'due' right lol,

Quote:

Originally Posted by Toby_Thump

sounds good when they bac fire!! :P haha!! lol but... yeh idle screw ^^

Mixture screw my man

elliott king · 15-04-2009, 08:39 PM

Quote:

Originally Posted by _James_

Mine sometimes back fires when the exhaust is loose

So I'd check that aswell.

mine does exactley the same...when i had my xsport...when the end can was off it it didnt back fire once but when it is on it it intends to go bang bang blllurrrr like its bogging out

...thats the pigs problem now

defuse · 15-04-2009, 08:46 PM

Quote:

Originally Posted by _James_

Mine sometimes back fires when the exhaust is loose

So I'd check that aswell.

yeah mine too good old 125klx

had some super fun today went out after it rained and had the most fun i had ever had drifting round mudd'e corners on the track so going out again tomoz

let just say my back and helmet was caked ! wooo... and as for the bike !!

_James_ · 15-04-2009, 09:55 PM

Quote:

Originally Posted by defuse

yeah mine too good old 125klx

had some super fun today went out after it rained and had the most fun i had ever had drifting round mudd'e corners on the track so going out again tomoz

let just say my back and helmet was caked ! wooo... and as for the bike !!

I would be out, but my carb is deciding to not like me.

spam up · 16-04-2009, 11:48 AM

my spark plug looks the same so im guessin i need to adjust my mixture,

so what should the mixture screw be like, is it 2 turns or somethin?