Bike takes off
- Thread starter rbautz
- Start date
YesImLDS
Member
Either your idle is set pretty high or the cable to the carburetor needs adjusted due to it being at part throttle when no throttle is being applied. This can be adjusted on the top of the carb itself and can usually be done by hand or it could be where the throttle starts from where their is an adjustment that can be made on the underside of the throttle. If all of these are not the problem you either have a kink in the cable somewhere or something keeping the carb in partial throttle.
Edit: this is assuming you have the stock NT carb
Edit: this is assuming you have the stock NT carb
YesImLDS
Member
Easy way to check if the carb is at partial throttle is to take off the filter and look in the hole to see what is causing the problem. If the idle screw is in quite a bit it'll keep the slide open. If the cable is pulling the slide open adjust accordingly to a point where it is shut or at you idling point then put the filter back on.
bluegoatwoods
Active Member
I definitely think that the trouble is a throttle that's stuck 'wide open'.
But first, you wrote that "when I stop it stalls". That's just a bit curious. Do you mean that at these times you've got the clutch lever pulled in (clutch is 'disengaged') or do you mean that at these times you've braked to a stop but the clutch lever is left out (clutch is 'engaged'), and the engine shudders to a stop?
This might not be too important. But, depending on your answer, it might give a clue as to what's going on.
But back to the throttle itself. Is your throttle cable able to move freely in its sheath? If yes, then I'd have a look at the brass slide at the end of the cable. Inside the carburetor.
That slide has a channel, or a slot, running lengthwise. The barrel at the top of the carburetor that this piece fits into has a tiny little 'nub' on the wall. The channel in the slide must match up with the nub in the barrel. So that the slide can slide up and down freely.
If the channel and the nub are not lined up properly, then that can cause the over-revving that you're getting.
If that checks out okay, then I'd look next at the idle set screw. If it's turned all the way in, for instance, then that could cause over-revving.
If those things check out okay, but you still over-rev, then come on back and we'll try to think of other possibilities.
But first, you wrote that "when I stop it stalls". That's just a bit curious. Do you mean that at these times you've got the clutch lever pulled in (clutch is 'disengaged') or do you mean that at these times you've braked to a stop but the clutch lever is left out (clutch is 'engaged'), and the engine shudders to a stop?
This might not be too important. But, depending on your answer, it might give a clue as to what's going on.
But back to the throttle itself. Is your throttle cable able to move freely in its sheath? If yes, then I'd have a look at the brass slide at the end of the cable. Inside the carburetor.
That slide has a channel, or a slot, running lengthwise. The barrel at the top of the carburetor that this piece fits into has a tiny little 'nub' on the wall. The channel in the slide must match up with the nub in the barrel. So that the slide can slide up and down freely.
If the channel and the nub are not lined up properly, then that can cause the over-revving that you're getting.
If that checks out okay, then I'd look next at the idle set screw. If it's turned all the way in, for instance, then that could cause over-revving.
If those things check out okay, but you still over-rev, then come on back and we'll try to think of other possibilities.
Why isn't the muffler installed?
2 stroke engines rely on a certain amount of back pressure to run properly.
Put the muffler on as it was designed to be and see how it runs.
In addition, you're not doing yourself, your engine or the hobby any favors by running without a muffler.
Tom
