Erratic Idle/Throttle

[Ride_Relief]

I'm new here so I apologize if this is a repost. I've looked around here and seen so many potential causes so I thought I'd post about it.
I just bought a 2003 that I believe is stock. I start the engine and get the idle adjusted so that it sounds right (the pilot air screw is out 1 1/2 like the manual says. It has poor throttle response. It doesn't seem to want to rev back down as quick as it should. It speeds up and slows down the idle on its own (as if someone is hitting the throttle). Then the real confusing one. Inevitably it will rev like its wide open without anyone touching the throttle, starts knocking real loud and turning the key and kill switch off don't kill it. It has to be stalled. The key and kill switch work in any other situation.
Thanks for your help.

 

[fastLANE]

It's getting to hot and "deiseling" igniteing the gas from the super high heat as apposed to the spark from the plug

 

[battbike]

sounds like a problem i once had with my throttle cable,did you try adjusting the cable next to the throttle, maby the cable is sticking a little. just a thought!

 

[Ride_Relief]

Thanks for the replys. I thought of dieseling but it hasn't ever run for more than 5 minutes or so at idle or a low revs until it goes wide open. I suppose its possible. Is there any way to tell (would the spark plug look different?) As for the cable, I'll look tomorrow but i don't think so because the throttle moves and feels fine.

 

[xxxxfloodedxxxx]

it actually sounds like you may have 2 or more simultaneous problems... check for cracked reeds... check for air leaks... are you running proper fuel?... still have injection system?... pull a plug, should be a nice dull tan/gold color... and check what batbike said above... my cable has slipped out of the boot at the throttle box before and made the motor idle/run erratic... get back to us with what you find out.

 

[blasterboy91]

or maybe dudes float needle is getting stuck open.it happend to my uncles 91 blaster

 

[hickskateboarder]

the blasters kill switch and key are incapable of turning the motor off at high rpm's. hold it wide open and turn it off and pull the key. i'll still be running wide open.

 

[regal81455]

sounds like an air leak spray wd40 or carb cleaner around the jug and the head and listen to the engine tone/rpm, it'll change if you've got one, sounds like what happened to me when i blew a head gasket...

 

[Ride_Relief]

Thanks for the tip. I'll check for leaks.
As for the kill switch not working at WOT...what the hell? Wouldn't that be a PERFECT time for it to work? What if your throttle stuck?
Update: I read up on jetting in DIY and turned the pilot air screw in and now she runs ok. No random WOT or sputtering idle. It has better throttle response and smokes now. I'll try to fine tune it this weekend. I know two-strokes smoke but how much is too much? Can running rich cause any real problems? Thanks

 

[Blaster.240]

The reason that your motor is idleing slower with the pilot screw all they way in is that it runnig to rich and this wiil ruin you engine. Waht you need to do is put the screw back to stock position and take of your seat and your air box lid. In between the gas tank and the rear fenders there will be a screw at the top of the carb. start the engine and rev it jast a little then drop the trottle. If it is reving high turn the scerw counterclockwise(it might be clockwise but if it start reving higher then turn it clockwise) it should drop the idle speed down. Now with trottle response takeing off you air box cover will help with that also what i did to get alittle more power out of it was to take off the tail pipe end on the exhaust. Just unscrew the three screws and pull it off you will need to adjust your pilot screw but not much and this will improve throttle response.

 

[Blaster_boy200]

it could be that you have a air leak my blaster was doing that so i took the carb off and put it back on and sealed it and its fine now

 

[Ride_Relief]

****sorry****
I should have specified that the pilot air screw is not all the way in. Stock is 1.5 turns out. Now its approx. 1 turn out. This, in conjunction with adjusting the idle, is what made it run better but start smoking more. I dont think anything is all that wrong with it, I was just curious what could go wrong if too rich or how much blue smoke is too much.
Thanks for your help. This site is awesome. I'm happy to be riding now.