Cafe Racer Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
My 1979 suzuki gs 550 has 4 broken off fuel adjuster needle screws with the tips stuck in the carbs.(Aaargh!)
Any suggestions for getting them out so I can put new ones in?

Thanks in adv

Distraught newbie got rooked!!
 

·
Registered
Joined
·
6,469 Posts
Hate to say it but if they mangled them bad enough you might be looking at a new or used set of carburetors.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #3
Thanks for the grim news which is what I exspected really. Just thought some bright spark might have a trick up his sleeve.
Gonna try freezing or heating up one carb and see if I can poke the bit out otherwise I'll try drilling it with suitable guide down the recess. Nothing to los here.
 

·
Registered
Joined
·
6,469 Posts
The problem is in the materials, the jets are brass which is soft but fairly dense material, the carburetor body is cast from powdered white metal that is similarly soft but far more granular in nature. Your challenge is going to be to drill only brass and not touch the white metal with your drill. The shape of the holes makes it impossible to drill all the way through, so that is going to require some precision drilling.
Best luck with the repair, if you can find a motorcycle scrap yard they will likely have plenty of replacements to choose from.
 

·
Registered
Joined
·
1,825 Posts
If you can drill them enough to use an easy out, before you try to turn them, put the carb in the oven and heat it to wax melting temperature, dripp some candle wax onto the jet. It should draw the wax down into the threads (like solder in a pipe joint) and make the jets easier to turn,
This is all based on the supposition that the white metal will expand faster than the brass. I've never actually broken a jet to need to try it on a carb but wax works in lots of other applications.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #6
If you can drill them enough to use an easy out, before you try to turn them, put the carb in the oven and heat it to wax melting temperature, dripp some candle wax onto the jet. It should draw the wax down into the threads (like solder in a pipe joint) and make the jets easier to turn,
This is all based on the supposition that the white metal will expand faster than the brass. I've never actually broken a jet to need to try it on a carb but wax works in lots of other applications.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #7
Thanks guys, my problem is there is just the tip stuck up the spout protruding half a milli into the main aperture.
I like the heat and wax idea so I'll give that a try. 👍
 

·
Registered
Joined
·
6,469 Posts
If you could seal the entire thing to pressure you could put a grease gun onto it and try pushing it out,
that works on some things, but I never tried it on anything like a carburetor body.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #9
Sorted. After freezing the carb,I made a mandrel on my lathe to take a 1mm drill bit and sit down in the aperture so as to line up the drill bit dead centre. Drilled it out a tiny bit and then turned it upside down. The brass bits all fellout brittle and crispy.
Done the second one same way so two more lucky ones to go.:D
Many thanks to all suggestions any one of which might have worked on a different day.
 
1 - 10 of 10 Posts
Top