I had an interesting experience on my 2005 PX150 a couple of evenings ago.
I was in the middle lane of 3 lanes in moderate traffic when I lost all throttle response.
The engine continued to idle but would not respond to the throttle.
Luckily, since the engine was idling I still had turn signals and could make my way over to the side of the road without getting run over.
After pushing the scooter down the sidewalk for about 2 blocks I found a suitably illuminated area to start to work on it. (Now I know to keep a flashlight in my toolkit )
During my walk I was assuming that the throttle cable had broken but I had a spare with me so no problem.
Once I got the box opened up and the air filter out of the way I realized that the throttle slide rod had come out of the linkage to the throttle cable.
I put it back on and went on my way.
Two days later (after dark again) I went to Home Depot and bought a suitable flashlight, and on the way home I lost my throttle again.
While putting it back together again this time I worked the throttle back and forth several times and I could see the rod rising up out of the linkage.
Sometimes it would fall back down, sometimes it would stay up.
So I took my needle-nose pliers and made an oh so slight bend in the rod to help it stay hooked in.
This, of couse, raised my idle a little but I figured I would just adjust it tomorrow in the daylight.
The next day I found out that adjusting the idle screw would not get my idle back down to where I wanted it so I thought maybe I put too much bend in the rod.
After consulting the Service Manual I think I have discovered that the rod should be entering the linkage from the bottom.
Mine was poking down from the top.
I had my carb rebuilt almost 3 years ago and it had been working fine, up to this point.
Should I just straighten out the bend I put in the rod and stick it back into the linkage from the bottom?
Or do you think I might be having other issues?