XT 125 X blipping throttle really fast from idle causes engine to cut out

[j0hn]

I was oiling my cables when I noticed that blipping the throttle really fast from idle causes engine to cut out. The cable isn't too tight or too slack but adjusting either way has no effect. If I blip the throttle slightly slower, it works fine and the engine doesn't cut out. The engine runs fine if you leave it running idle so I'm not sure what the problem might be. This could all just be me but I'm pretty sure I could blip the throttle really fast (rev bomb) and the engine wouldn't cut out like it does now. Any ideas where to start looking?

//Edit: Just went out for a ride today and it didn't feel any different. I guess it was just me, blipping the throttle as fast I was doing seemed a little abnormal anyway. Would still like to know why the engine cuts out, maybe too much fuel in the mix?

[dt502001]

No jhon not rich lean if you carb has a accelator pump the seals need to be checked/replaced

[j0hn]

I've looked at an exploded diagram for the carburettor and the thing looks complex. Not sure if possess the level expertise to meddle with it. The Haynes manual doesn't go into much detail so I would be lost if I mess up. Just over 8k miles, it's well due a check up and clean, but as always, I start messing around something I don't know anything about and the worst case scenario always comes around .

I was thinking of buying a used carburettor and learning from that first but haven't seen any yet.

[Alexengongong]

what is the idle RPM at the moment?

[Prichard XT]

is your idle is set to low the xt is supposed to run at 1650 rpm

I run mine at 1350 rpm

how old is your battery more than 3 years could need replacing

and check the fuel filter float needle

aint clogged usually bits of plastic from the tank cap seat

try running a bit of redex through it

if this doesn't help clean out the carb need any pointers PM me

iv had mine apart to many times, had to tweek it after a drop ruined my float hight

and changed the jets iv also used a xt carb on a 150cc project

could be of help?

[j0hn]

I didn't know the idle was supposed to run at 1650rpm. The manual says it should be between 1300 - 1500, mine settles at around 1400. The battery is around 8 months old but I have it regular plugged into an Optimate. I don't actually feel any difference when riding and haven't stalled at all so it must have always been that way. I'm not really sure how the XT is supposed to act when you go from close to fully open throttle in a split second, does yours cut out when you fully open from idle as fast as you can?

How often should you really clean your carb? I'm just waiting for a period of time where I don't need to use the bike for anything so I can spend a few days cleaning this carb because I know for a fact that I won't be able to get it all done in one session lol.

[Cynic]

Its a 4stroke. More importantly a small high rev 4 stroke.

The fueling at full throttle is far above what it wants at idle. On a fi bike the system takes over thinks 'twat' and sorts it.

Its why cv carbs are used on bikes as they lift the slide proportional to the motor speed. Your just exceeding whats possible. The engine isnt running fast enough to process the fuel and air your adding. So cuts out.

[j0hn]

Ahhh, that makes sense! I wasn't really sure why that was happening, thanks for explanation.

[Prichard XT]

well yea it does happen to me

only when I dump the accelerator from really really low rev's

I put it down to the amount of restriction on this bike

and that would tie in with what cynic sayed

take as much of the restriction off as possible if you want to prevent it happening

and cv carb is this the type with some sort of air vacuum on the top which draws theaccelerator pin up