Slide sticking in left carburator '66 Superhawk

doug evans · Post by **doug evans** » Sun Apr 12, 2015 4:02 pm

Hello folks,
Got a small issue with my 1966 Superhawk.
Hope the group can shed some light.
Bike is all original w/ 6800 miles and was brought back to life
approximately 5 years ago by Taka at Peak Point
in Brooklyn, NY. I bought it from a customer of his.
I have ridden it in 9 Moto Giros and have done all regular servicing
myself. Only problems in those years were a bad condensor and a
faulty rectifier.
In preparing for this Spring's Giro, I had a situation at start-up.
Engine raced at 4500 RPM on start up and was impossible to bring back
to idle.
Long story short: Disassembled the carbs and found the left carb slide hanging
up in the bore of the carb. NO apparent scoring on either the slide or the bore.
This situation only materialized this Spring. Was fine last Fall. Fuel stabilizer used
in a full tank when I put it away last December. I have always been careful about
the tightening of the carb to head nuts.
Don't want to mess anything up, so I haven't tried to burnish the bore OR the slide
Any help would be appreciated.
- Doug

G-Man · Post by **G-Man** » Sun Apr 12, 2015 11:51 pm

Operate the tight slide with your finger until it hits the tight spot. Relieve any shiny areas inside the carb with fine wet/dry paper and repeat the process until free. Unless there are burrs on the slide do not touch that.

G

doug evans · Post by **doug evans** » Mon Apr 13, 2015 3:44 am

Thanks, G-Man, any particular grit?
Thinking 400?

SMBH · Post by **SMBH** » Mon Apr 13, 2015 4:16 am

Make sure you have the correct O rings on the carb intake and not over tighten the nuts as this will distort the carb flange and this will make the slide stick, may I surgest you use self locking nuts on the flange.

Go easy on the wet and dry as if you make it too loose air will be sucked up between the slide a body this is always the problem with AMAL Mono and Concentric carbs on brit bikes here in the UK there are firms that will bore out the carb body and put a brass sleeve on the slide.

Try starting with a metal polish like Sovel autosol on the body remember what you take off you can not put back on.

G-Man · Post by **G-Man** » Mon Apr 13, 2015 4:55 am

I would go with 800 or 1200

doug evans wrote:Thanks, G-Man, any particular grit?
Thinking 400?

48lesco · Post by **48lesco** » Mon Apr 13, 2015 9:27 am

You might try just a good cleaning with some white scotchbrite and gumout first. Especially if it was working well last year. It doesn't take a great deal of varnish to make a slide hang up. I say white scotchbrite because you can see the if your getting anything.

leonvjames · Post by **leonvjames** » Fri Apr 17, 2015 3:16 am

I would also check the throttle cables, specially the junction box area. Also the carb tops, if these come loose it can effect the idle.
Leon.