Hi

I'm new with 2stroke engines AND with Yamaha, and i have a small problem. DT doesn't start with kickstart but it starts when pushing 10-20 yards with gear2. Then it runs perfectly... When hot, idlerunning is impossible. When letting throttle off, revs doesn't go below 3000rpm, it goes down to 1000 if i let it go a while with 3000 and then revving to 4-6000rpm, then it drops to normal idle, but stalls after about 15 secs. Carb is orginal Mikuni28 with 270 mainjet, and it is 18kW mode with no restrictions and 90% working YPVS(too long wires).

Hi

I'm new with 2stroke engines AND with Yamaha, and i have a small problem. DT doesn't start with kickstart but it starts when pushing 10-20 yards with gear2. Then it runs perfectly... When hot, idlerunning is impossible. When letting throttle off, revs doesn't go below 3000rpm, it goes down to 1000 if i let it go a while with 3000 and then revving to 4-6000rpm, then it drops to normal idle, but stalls after about 15 secs. Carb is orginal Mikuni28 with 270 mainjet, and it is 18kW mode with no restrictions and 90% working YPVS(too long wires).

Thankfully it is most likely tro be one of 2 problems.

first of all take out your carb and give it a good clean. Good and proper not just looking at it and saying that clean enough.

Make sure any rubber connectors like the mounts are not persihed and cracked (so they let in air)

So that's good for starters. Poor fuel or air leak.

Yep.....the symptom of High idling is often times due to air leaks.

JimJam is right on top of it.

so hi by the way did you sort the problem out and if so what was the answer