Idling

[Celt]

If the bike runs well while riding but stalls when you leave it idling while opening your back gate, what needs checking to put it right?

[THE FLUTE]

Is that when it,s cold or hot ? if it,s when it,s hot turn the tickover screw in on the side of the carb

[edarter]

Do CRM's have a separate idle jet ? If so it could be blocked / worn.

Ed

[lee_p]

Sounds like the chokes on cos its stone cold, they tick over for and 20 seconds before choking itself to death.

Lee

[kinney]

If the bike runs well while riding but stalls when you leave it idling while opening your back gate, what needs checking to put it right?

Hi Celt,
Small two stroke engines are notorious for oiling up if left ticking over for any length of time. Fuel and oil builds in the bottom of the crankcase due to the low gas velocities at idle. The engine gets more and more spluttery, as the forming puddle interfers with the incoming idle mixture, and eventually cuts.
On restarting and riding away, that excess fuel and oil can be seen in the form of lots of smoke as it gets ejected by the now much higher gas velocities within the engine.
That said, your CRM should be quite capable of idling long enough for you to get the gate open and your helmet and gloves on too.
If your tick over speed is set correctly, try the following.

I would first just check the spark plug. Make sure its the right one, clean, and correctly adjusted.
Then, go for the carb. Dead simple piece, on a CRM, and dead simple to remove and strip. No need to go mad, just take it off and remove the float bowl. Take off the float and float needle and remove the two brass hexagon shaped jets. Last remove the choke plunger and air screw (not the idle adjustment screw).
Blow out every jet and gallery you can see, preferably with a compressor or by blowing through a piece of small diameter tubing placed over the holes.
You're bound to find plenty of crap in there so give it a good clean out.
Check the choke plunger for damage to the rubber washer in the end.
Check the float valve for a ridge in the rubber cone.
If either of these items are leaking, they'll need sorting.
Re-assemble the carb preferably with a new float bowl gasket, but a good seal can be attained by cleaning up the old one and assembling with a VERY LIGHT smear of silicon.
Set the float height at 16mm and the air screw to 1.25 turns out. (2.25 turns for the mk1)
Re-fit your carb and give it a try.
This should solve any carb related idling problems.
Let me know if it still doesn't idle and we'll move on.
Your carb will have had a much appreciated clean out whatever.

Andy.

[edarter]

very useful description there Andy - I'll be using that for when I strip the carb on mine !!