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Carb Trouble

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I bought a 10k miles 640E with a BST 40 carb that ran fine. I took the carb apart and found the needle was almost worn through so I replaced it with new plastic and metal washers. Bike runs fine except at idle will stall and occasionally die (when stopped at lioght, etc). I messed with the fuel screw with little change. I did notice when I turned the screw all the way in the bike didn't die like I thought it should.

Any Ideas? Want to get it ready to sell.

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I got a 5,000 mile 2002 Duke II carb (BST) if you are interested. Nothing wrong carb, removed for a FCR install

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Also check the enrichment circuit (BST choke).

I had the stupid plastic nut back out and I was running with

partial enrichment. Also the spring in the enrichment plunger

assembly has been know to come out when the nut backs out.:thumbsup:

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Thanks to Thumper996 and his old BST 40 the LC4 is now running great. Didnt even have to touch the jetting. If anyone is interested I have a ton of brand new parts in my old carb for sale. The bike is going to be for sale in the northwest area soon as well.

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After running the bike for a while and warming it up all the way I discovered the problem still exists, at least I feel rairly confident I can rule out the carb. I threw a FCR in it for a while as well with the same problem but I wasn't confident about that because I know they can sometimes take alot of adjustment to make the FCR work right.

Checking the coils next.

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