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Discussion Starter #1
It's a 2000 scrambler 500 4x4. Just got it and it would idle fine but bogged when you gave it throttle plus it was leaking fuel from the bowl overflow. Took carb apart and it was pretty filthy....pretty obvious the main jet was clogged and that's what was causing the bogging. The o-ring on the needle valve was jacked up and that's what I figure was causing the fuel leak.

Get a rebuild kit and replace both jets, float needle, needle valve, ect ect. and now it won't start at all. Carb is getting fuel because I opened the bowl drain and got fuel out of it. 99.99% sure my lines are correct because I labeled them when I took them off. Any ideas on where to start troubleshooting it at? My petcock is leaking pretty bad and I have one ordered which should be here tomorrow. This was my first carb rebuild so I'm pretty sure it's probably something I done but the rebuild was pretty straight forward. Didn't really hit any parts that threw me. I cleaned everything really well and took my time putting it back together. I was extra careful with the float to make sure I didn't bend the adjustment tab for the float needle. I'm just not sure where to start at with it.
 

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Did you remove/replace the mixture screw? Its very easy to lose the tiny o ring and washer or get them in wrong.
Also, did you compare the jet sizes of the kit to make sure they are the same as the old ones?
 

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Discussion Starter #3
First off....thanks for the reply.

I did compare the jets to make sure they were at least visually the same. As far as the mixture screw.....I forgot about that part. That's where it was kinda funny. There was no fuel screw. It was smooth with just an orifice in it. The picture I was going by from here The BST-40 Bible - ADVrider shows a screw in that position. I thought it was kinda odd but thought that it could just be a little different model or something. I'm going to pull that carb again today at some point and go over everything again. I have the original idle jet soaking in carb cleaner and I may try to put that back in there to see if there's any difference. I really don't feel like that's the issue though. I think I missed something else somewhere. Even though I got the kit from the dealership it didn't have a couple o-rings I would've liked to replace like the o-ring around the top of the slide guide. I'm also kinda assuming that the leaking petcock valve wouldn't cause a no start condition right? It's leaking pretty good but fuel is getting to the carb because I opened the float drain and fuel was in the bowl. I try to be a silver lining guy when I can and the silver lining is that the leak down the overflow tube stopped so I at least fixed that problem haha. Just need to get it running now.
 

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It's very likely that the brass plug is still in the hole covering the mixture screw. Need to carefully drill through it and pop it out to get to the screw. Also, check the numbers on the jets to be sure they are the same. Visual is not a good enough check. That will only tell you if they are the correct style. The numbers stamped on them tell you the diameter of the hole in them. Make sure you turn the mixture screw in and count the turns till it lightly bottoms before backing it out so you can put it back in the same setting after. Also, did you remove the idle screw? If so maybe you didn't turn it up far enough when reinstalling.
 

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Discussion Starter #5
ok...so that's a plug covering the screw. That makes more sense. I did remove the idle screw and turned it in more thinking the same thing you said. I will check those numbers on the jets. I did clean and swap back in the original idle jet with no luck. I have a buddy that's rebuilt a ton of carbs. He's going to stop over this evening after work and give me a hand with it. I think I may wait until the new petcock gets here before messing with it anymore though. Tired of getting gas all over the garage. I'm hoping it gets here today....ordered it a week ago. Ordinarily I would've just waited on it but I was really looking forward to firing it up and my excitement got the best of me.

Thanks for the suggestions guys......I appreciate it. I'll get it.....I always do. I just gotta figure out what I did wrong.
 

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Discussion Starter #7
got the petcock in and it fired right up. I knew it was leaking but the fuel in the bowl led me to believe it should've been getting enough gas to run. Guess I was wrong. Got the idle set so now I'm going to put the 2398 bolts back in it and give it some test drives. I'm leaving the front plastics off until I can ride it and check it for leaks and what not.

Thanks to the both of you guys for chiming in with some opinions and advice. I rely on the boards a lot when I work on stuff because there's always several very knowledgeable and helpful people on them. It's nice to have people to ask questions when I get stuck. Since this was my first carb rebuild I took my time and did a bunch of reading ahead of time but you know how that is.....still the first time so there's places to mess up.
 
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