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Discussion Starter · #1 ·
Hi Everyone

I've stripped my carbs on the F650 ST 1997 because I was getting black sooty smoke on high revs. When I bought the bike the seller told me he had replaced the main jets with "larger" ones?? I've ordered a pair of carb service/repair kits from the well known auction site rather than buying all the individual parts from BMW.

I bought the bike as a non runner and haven't had it out on the road as yet.

My question is on the left hand carb (in photo there is a brass rod---?Jet but on the right hand carb there isn't.

Is this normal or should they be symmetrical?

My haynes manual doesn't shed any light on it and the exploded diagram on RealOEM.com - Online BMW Parts Catalog
doesn't really help either.

If any one can tell me to either put one in both or leave it as is that would be an immense help.

Many thanks in advance from UK Stay safe and stay healthy folks
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I've got some spare bodies in the shed. I'll check tomorrow.... My Clymer and BMW manuals don't make it clear either
 

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Hi
It is the choke , think it only operates on the one carb being a single .
check by looking where the choke plunger screws into the body it is not linked do not think it is linked in anyway to the right carb body.
 

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Discussion Starter · #5 ·
Hi
It is the choke , think it only operates on the one carb being a single .
check by looking where the choke plunger screws into the body it is not linked do not think it is linked in anyway to the right carb body.
Brilliant! thanks mate, That makes sense it runs to where the choke plunger screws into the body. Doh! should have spotted that. I guess that means it's not missing from the other carb.
 

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Discussion Starter · #6 ·
I've got some spare bodies in the shed. I'll check tomorrow.... My Clymer and BMW manuals don't make it clear either
Hi again Steve. I did slightly damage one of the idle mixture screw holes getting the seized screws out. If you were considering selling a spare set of bodies I would be interested. Cheers Craig
 

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If the threads are ok you can carefully dress/or drill the inner of outer part round again care not to damage threads , as the pic the picture is not that clear it just looks like the spigot part is out of round internally ?
 

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Discussion Starter · #8 ·
If the threads are ok you can carefully dress/or drill the inner of outer part round again care not to damage threads , as the pic the picture is not that clear it just looks like the spigot part is out of round internally ?
Yes the spigot part. A little snapped off It was just rested in place for the photo. I will liquid weld it back into a more exact position and then run a tap down the thread. You don't happen to know what the thread is by any chance?
thanks again
 

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Discussion Starter · #12 ·
the repair kit comes with them I hope. got the springs but the o rings disintegrated with the drilling. Threads look reasonable but I'm nervous to put the new parts in only to find I damage them too!

 

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Discussion Starter · #15 ·
Hey Mate. No both screws had to be drilled.
coding is not very clear but I can make out:
D6T33
B373
K6B5
 

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Discussion Starter · #17 ·
it was Just a thought on old screw you could have made a thread chaser out of old one.
Good thought. when the new ones come I'll see if I can work what the thread is and go from there.
You've been really helpful mate. Thanks
 

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Discussion Starter · #20 ·
I think the pitch is 0.75mm or 0.7 just can not remember not sure of diameter but if i took an educated guess m6 or m5 but you might be able to measure hole dia.

see this

Thanks. Looks like everything I need is in the repair kit. I'll save this posting anyway as a back up, just in case.
 
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