100% stock 1982 cb750sc nighthawk

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100% stock 1982 cb750sc nighthawk

Billcb750sc
Hello I new to the bike I bought from origanal owner it's been sitting in a shed for the last 5 years brought it home replaced the battery,oil,all filters with oem ones fresh plugs cleaned and rebuilt carb and replaced all vaccum/fuel lines with oem Honda carb kit but still can't get the bike to idle down it idles between 3500-5500 does anyone have any ideas the guy I bought it from road the bike everyday
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Re: 100% stock 1982 cb750sc nighthawk

TOOLS1
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Two things come to mind, first the pilot jets are still plugged, second you have a vacuum leak, or both. Check the rubber boots between the carbs and head, and the aircut valves for vacuum leaks.
TOOLS
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1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: 100% stock 1982 cb750sc nighthawk

Billcb750sc
Ok thank I just ordered air cut diaphragms that is the only part of the carbs that are not new carb to head boots don't leak sprayed with carb/choke cleaner and no change in idle speed so no leaks their
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Re: 100% stock 1982 cb750sc nighthawk

icerigger
In reply to this post by Billcb750sc
The idle jets are a bugger to get clean and clog up at the drop of a hat. Some people on here (myself included) have taken 3 or 4 shots to get them right. The last time I ended up replacing the idle jets to get it to idle properly for any length of time.

When you cleaned the carbs did you Chemdiip or ultrasonic?
Livin' my life like a song.

1985 Honda Rebel 250 - "Birdie"
1979 CB750K - "Behemoth"
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Re: 100% stock 1982 cb750sc nighthawk

shinyribs
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In reply to this post by Billcb750sc
Billcb750sc wrote
 sprayed with carb/choke cleaner and no change in idle speed so no leaks their
Carb cleaner isn't strong enough. Even spraying directly in to the carburetor doesn't produce much, if any, rise in rpm. Try it with starting fluid and see what you find.

My bet is pilot jets or vacuum leak, like Tools said, or synch.