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Hello, I'm new to the forum but Ive been trolling on here for a quite a while. Its nice to finally join you guys :D

Anyways, I bought a 1971 CB175 about a month ago and have done quite a lot of work already, and have had quite a crap load of problems. I fixed most of the important ones, but I just cant get the sucker to idle right! The main problem seems to be that once it fires it will idle okay but when i pull the throttle the idle stays high (sticks), I have been messing with the air screws and the throttle stops for days now... ( i already checked and the throttle isn't sticking at all) I cant get it to come back down unless i kill it and then fire it up again.
I also checked for cracks/leaks at the carbs and gaskets by spraying starter fluid while running.
I think it is a fuel issue as the spark plugs get quite black very fast. but im just dumbfounded....... Im open to anything, just shoot me an idea and ill try it out! (I would just love to ride it at least once before winter... (Oh Great Michigan))
The one problem is that the bike came with no tachometer cable and mine still hasnt arrived so i cant give you guys RPM numbers, but it sounds like its idling so high that its almost, 4-5.5k?

Here is what i have done / checked already for this issue:
*Spark - both cylinders have a spark, replaced spark plugs, checked spark wires, (it obviously fires so electrical should be fine(?) but could it be timing issue?
*Carbs - Thoroughly cleaned (multiple times)and (even scrubbed) every orifice, hole, crack. Soaked carb parts in cleaner. Main and idle jet look good, no defects, completely clean. One float is brand new, the other one i re-soldered two days ago and adjusted for difference in density. Both carbs have fuel filters. **** P.S.What settings do you guys use for your carb. screws?***
*Throttle - Checked for sticking, synchronized throttle on both carbs., Set throttle stop at 2 turns from soft close.

I will try to take and post a video today as well of the problem, along with some pictures of the bike. :mrgreen: However its still in pretty rough shape. The previous owner, or 20(?) did quite a number on it....... :cry:

Thanks to Everyone in Advance,
Dmitriy S.
 

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Just my personal experience -

175's and 200's are really fussy about throttle cable routing - it has to be just right or it does that, it should really be a bit longer but it ain't........
The forward tank mounts can also bugger the cable if you're not careful putting the tank on.

On a CB200 you have to take off the whole manifold to get the carb off, think it's the same on a 175??
There are o-rings in there, so the unit has to be bolted back on very carefully, first one side a bit, then the other, evenly.
Otherwise the o-ring gets deformed and you have a big ol' air leak.
 

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Sensei
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Possible solution..... Air mixture screws should be between 3/4 and 1 turn out (7/8 to start, + or - 1/8)..... There IS NO Specific idle screw position....you just adjust them alternatively until the bike idles at 1200 to 1300, and ANY adjustment of either idle screw changes the idle speed (essentially balancing or "syncing" them)
Sticking at a higher idle could also be the advance unit or point timing....
 
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