weird!!!!!wants to run...or does it????

28 replies to this topic
  • 4Stroke4Life

Posted September 17, 2004 - 03:42 PM


well we tried to unplug the TPS today (friday) and the bike is still doing the same thing. we never took out the slide in the carb so i don't think it is that.what are the chances of the slide getting off track by itself w/ out being removed?? me and the guy who is working on my bike are both stumped at this point. my mechanic is a younger guy. my age about 23. he graduated from MMI (moyorcycle mechanics institute-phoenix) last November. so i know he is still new. but i am pretty confident he knows his stuff. like i said we are both stumped and do not know where to turn. so any help would be sweet!!!!!! :cry:

  • Fastest1

Posted September 17, 2004 - 08:00 PM


The slide wont do anything accidentally. If you didnt remove it since it was running correctly, there was no chance of installing it backwards. It happens to quite a few of us. It doesnt sound like your problem since you didnt take it out.

  • Fastest1

Posted September 17, 2004 - 08:10 PM


I also thought of something else. You say they cleaned it and gave it back to you. Have you looked down the bore of the carb while twist the throttle? Do you see a fine mist or spray? I now think your accelerator pump isnt working. I reread your post. It would do that exactly. It will idle correct? If you give it the gas quickly, it falls on its face? (dies) You can slowly get it from idle to a higher rpm and it runs fine? It wont transition there easily? You can either take the carb off the bike and hold it in your hand, making sure the carb has fuel in it. Twist the throttle if still hooked up of just move the linkage by hand, it should spray a very small stream of gas (dont be looking at it directly :cry:). The 99's are notorious for either getting gunked up because of dirt or the pump diaphragm cracks. Either way if there is no spray, it wont come off of idle. Good Luck.

  • 4Stroke4Life

Posted September 18, 2004 - 06:53 AM


right on fast1. thanks for all your help. i do know that my diaphram did have a little bit of rust on it, and gunked a little. i will try to just replace it next. i cleaned it w/ a wire brush and carb cleaner, but maybe that wasn't good enough.any ideas on what may have causedthe underside of the diaphram to rust??? i mean RUSTY!!! :cry:

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  • Fastest1

Posted September 18, 2004 - 07:37 AM


I would guess moisture in the fuel. Or sitting up a long time and evaporating. The 98-99 models apparently arent sealed like the 2000 and later so they have a tendency to get packed with dirt and such. Do you see a spray when you twist the throttle? If you have the airbox/subframe off and leave the carb on you should see this little (I mean little) fine spray toward the intake, it should just miss the bottom of the slide just as it starts to open up. Usually will last about .5-2 seconds depending on the duration. This is what causes the notorious bog in the 2000. The Bk mod was the cure for ours, but the 98-99 I believe do the P-38 mod. Too much or too little fuel from the accelerator pump will cause this problem. 4 stroke take a little fuel at low rpms to get off the bottom. Not enough vacuum at low rpms or too big of a carb.

  • Fastest1

Posted September 18, 2004 - 07:49 AM


I did a little search for you, for what was referred to as the "wheel collar mod". I am not suggesting you do that yet. Just confirm and time the spray if possible. Here is the link http://www.thumperta...true#Post488349
This problem comes up quite often. Again good luck!

  • 4Stroke4Life

Posted September 28, 2004 - 09:04 AM


i know this is kinda stupid??? but my bike still is not fixed. i picked it up from the shop it was at, (they could'nt figure it out, yeah won't be going back there) and took it to another shop, who i heard about through a friend. but anyway... one thing we did NOT do is change the spark plug. it only has three rides on it, but i THINK, from what i understand, spark plugs on 4(don't)SMOKES... still foul, but not like a 2SMOKE. it could still run or be hard to start. does anybody have any ideas to it maybe being a fouled spark plug??????????????? please help me!!!!MY BIKE HAS FALLEN... AND I CAN'T PICK IT UP... :cry: :cry: :cry: :lol: :lol: :lol: :cry: :cry:

  • Fastest1

Posted September 28, 2004 - 10:11 AM


From my experiences, a 4 stroke plug will foul but it wont start. If it starts with teh plug that is in it, I would say it is not the plug. I still suspect the gas tank vent or hose. Fill the tank about a quarter full and unscrew the cap and ride and see if it changes. :cry:

  • 4Stroke4Life

Posted September 29, 2004 - 04:37 PM


Well, the other shop FINALLY figured it out. my stator (brand new-3 rides on it ) is CRACKED!! what the... THERE IS NO CHUNKS OF METAL BIG ENOUGH TO CRACK IT IN THERE... FOR SURE. beats the hell out of me. so now :cry: i have to replace that one as well. anyway, thanks for everyones help.

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