Atomik 160cc doesn't idle but has spark

[ayjayjay]

Hey guys, brother in law has an atomik 160cc big foot, for some unknown reason the bike has spark everytime you kick it over but will only fire up then stall maybe after the 20th kick, could this be magneto/stator or even cdi at fault? is there a way we can test the units we have at the time. have been told he has the inner magneto set up.

cheers

 

[my67xr]

Those inner rotor kit's are not worth using.
They fail prematurely, and some of the,m won't even work out of the box new.

I would be fitting the stock YX160 stator, flywheel, loom and cdi back onto it, you will notice it wll have a lot better engine braking and not want to stall as much through the corner's etc.

Stator/Flywheel- Magneto Stator Plate Flywheel Roller YX 150cc 160cc PIT PRO Trail Dirt Bike | eBay
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I would be checkin for a spark plug that look's a little wet, so you know it's getting fuel too
Also check the condition of the plug, they are about $5 new NGK C7HSA

It could have a blocked up pilot jet, or pilot circuit.
So might be worth pulling the carby down and giving it a decent clean out and blow some compressed air through it while you're at it.
Take the jet's out and mixture screw out and make sure the hole's through the middle are open, and the hole's across them
Blow the compressed air into the 2 or 3 small port's on the air filter side of the carby to check for blockage there too.
You should feel air coming out one of the hole's in the bottom of the carby where the jet's go

Look into the bottom of the hole where the pilot jet screw's into and make sure you can see light through the tiny hole.
Even poke a strand of copper wire through it to make sure there is no gum/varnish (dried up fuel) restricting it.

Stock setting for the mixture screw is around 1.5 turn's out from fully seated.

 

[ringo]

I agree with 67, check the carby first, you might find it's something as simple as a low idle, try bumping the idle up and retry starting it again.

 

[ayjayjay]

Thanks loads guys!! Always great help

 

[ayjayjay]

hey guys, we've pulled out the old inner rotor kit and installed the standard 160cc stator kit and idles killa!!
but soon as you turn the choke off, the exhaust and carby starts popping and back firing.

Now we used a good known spark plugs, same result
used clean 98octane fuel, same result

would it be something to do with the carby? i.e. different size jets to suit the inner rotor kit?

any help would be much appreciated

 

[my67xr]

How many turn's out is the mixture screw set at ?

And have you checked all the electrical connection's stator to main loom, loom to cdi, main loom to coil, coil to earth ?

 

[pitsterproAUS]

also check u don't have a exhaust air leak or intake manifold air leak

 

[ayjayjay]

Thanks for your help guys!! we rechecked the wiring - was all ok, pulled the carby apart and it was completely dirty, cleaned that out, refitted it and if anything it got worse, took the carby apart, rechecked everything and of course cleaned it some more, re-installed it, kicked first go and all went well!! so still now it remains a mystery whether it contained a block jet or what.

thanks for all your input - this weekend we go riding

 

[ayjayjay]

hey guys, tried researching the exact information but no luck.

Air/Fuel mixture screw - to screw in or out, which way is lean and which way is rich?

 

[my67xr]

In is richer, out is lean.
Standard setting is around 1.5 turn's out, then tune it to suit your combination from there