Backfiring Atomik 125CC Moto X

[heathmynhart]

Hey guys,

A mate of mine has a 125CC Moto X. He has just got into riding and i'm trying to iron out a few issues for him. After running in for about an hour, it started backfiring and I saw some flames out the exhaust holding the throttle on about 1/4.

I have checked and changed the valve clearances, changed the fuel mixture and also changed the needle position in the carby.

It is much better now, but still backfires at about 2/3 throttle. I will oil up the air filter a bit more as I think that will make it run a bit richer. But I think is it something else to do with the carby. I will check the float level and see if the jets are blocked.

I’m not sure what size jets it comes with, can anyone recommend what size jets to use?

Can anyone help?

Thanks

 

[heathmynhart]

Can anyone help?

 

[eichkay]

if its only early in the throttle you might find the pilot jet is way to big for that motor..

Open the carbi and look at what jets the bikes got ... no one going to know what jets are in your mates carbi, its a china bike it could have anything.

 

[Hillz]

is the exhaust loose?

 

[heathmynhart]

Nah exhaust isn't loose. I will check to see what size jets are in there. What size jets should it be running?

Cheers

 

[my67xr]

you havent mentioned what sort of carby and what size it is too?

 

[heathmynhart]

ah crap, its a 26mm mikuni. I know its not the best carby, just trying to sort out the issue. will most likely upgrade it later

 

[Reecey]

Ive got one and it still does it to this day! Carby full crap

 

[DHZ_XR8cing]

Does it back fire when you back off??

 

[GooseMan]

check the leads connecting to the coil, if they got water or mud or something in the connections then might have something to do with it.