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03 450 , in storage/will not start now

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Ok , we have been racing 2st bikes forever .

Now ,, this is our 1st veture into thumper land.

A close friends 2003 450 , very very low hours ( like maybe 15hrs). Bike ran strong , and always would start with in 3-4 kicks cold.

He drained the gas tank , but not the carb or carb bowl.

Fast foward 3 years ,, we buy it.

BEFORE i tried starting it , i pumped the tires up , checked ALL oils and fluids, ect.

The air filter turned into gumbo pie , i took that out and re installed the screen ( just to fire the bike up).

Drained the turpintine smelly old gas outa the carb bowl. Very stinkey. Squirted some carb cleaner up in there . Put bowl drain plug back in , put a 1/2 gallon of fresk fuel in the tank.

Kicked for awile , nothing doing.

Took the plug out , dribbled some gas in the hole , re installed and kicked some more . Some popping and it poppy ran for 20 seconds. Re assembled bike , would not start.

Subsequent trys with or without dribbling fuel into the sparkplug hole , with or without throttle or choke ,, Nothing doing.

Checked for spark ,, have spark. ( only can see approx 1 spark per simulated kick , wierd )

Even with the plug out , still have compresion , also wierd to me.

Most engines with or without clogged carb will start pop numerous time with a dribble of fuel in the hole. This machine will not.

Help please !!

Thanks !

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Ok , we have been racing 2st bikes forever .

Now ,, this is our 1st veture into thumper land.

A close friends 2003 450 , very very low hours ( like maybe 15hrs). Bike ran strong , and always would start with in 3-4 kicks cold.

He drained the gas tank , but not the carb or carb bowl.

Fast foward 3 years ,, we buy it.

BEFORE i tried starting it , i pumped the tires up , checked ALL oils and fluids, ect.

The air filter turned into gumbo pie , i took that out and re installed the screen ( just to fire the bike up).

Drained the turpintine smelly old gas outa the carb bowl. Very stinkey. Squirted some carb cleaner up in there . Put bowl drain plug back in , put a 1/2 gallon of fresk fuel in the tank.

Kicked for awile , nothing doing.

Took the plug out , dribbled some gas in the hole , re installed and kicked some more . Some popping and it poppy ran for 20 seconds. Re assembled bike , would not start.

Subsequent trys with or without dribbling fuel into the sparkplug hole , with or without throttle or choke ,, Nothing doing.

Checked for spark ,, have spark. ( only can see approx 1 spark per simulated kick , wierd )

Even with the plug out , still have compresion , also wierd to me.

Most engines with or without clogged carb will start pop numerous time with a dribble of fuel in the hole. This machine will not.

Help please !!

Thanks !

Sounds like you need to pull the carb and strip it down and clean it really well with carb cleaner and then blow it out really well with air. Maybe replace the o-rings since you will have it out and apart. One thing you need to watch for is to install the vacuum release plate on the front side of the carb slide right side up. Very common to put it back in upside down.

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yep . to pull the carb , does the subframe have to Go ? sure looks that way.

Thanks for the advise ,, there are LOTS of components on the carb i positivly do not recognise compaired to all the 2st carbs weve had ( very familliar with them , maybe that will help as i dive into this monsterous 4st carb )

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yep . to pull the carb , does the subframe have to Go ? sure looks that way.

Thanks for the advise ,, there are LOTS of components on the carb i positivly do not recognise compaired to all the 2st carbs weve had ( very familliar with them , maybe that will help as i dive into this monsterous 4st carb )

You can pull the top bolt from the subframe and losen the 2 bottom and pull it back so it sits on the rear tire. The airbox boot should have a tab on the bottom that you can grap with pliers to pull it from the carb.

Yes more components but it is still easy to do. Just a lot more work. Also, get a service manual it you don't already have one. Hope this resolves it. After this you may have to look into the valves...

Edited by mrmoto35

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Sounds like the pilot jet is clogged. Order a jd jet kit and don't look back. Don't remove the black sensor that's on the side of the carb. If you do you'll need to have it reset by a professional.

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Update !

The beast runs !!

( main culprit was a very plugged pilot jet .... )

Id like to thank you all for the help, and there very well may be some more questions as i learn this new machine!

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Thats great news! It is always a great joy to find something simple but elusive that resolves an issue that has you thiking in the back of your mind "oh man, please don't be somthing expensive"

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