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sparkplugs?

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davomoto
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Post by davomoto » Sun Jun 19, 2011 9:16 pm

The screw in the middle is the idle screw. The one in the front is the idle mixture screw.

Davo
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e3steve
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Re: cb77

Post by e3steve » Mon Jun 20, 2011 5:39 am

naptown68superhawk wrote:i tryed it both ways. switched slids around. had cutouts facing engine and airfilters. when the cutout is facing the airfilters it would idle super high around 4000 rpm. just a question, is the front screw the idle or is it the one right in the middle. the one on the bowl is to drain i know that much, but not much more. im waiting on my book to come in from the honda dealer.
Super-high idle is indicative of a lean mixture. You wrote that you followed Ed's Recipe, but without knowing the difference between the idle speed screw and the idle mixture screw, you may have 'screwed' it up!

Remove the tank (or lift the back end of, and wedge it so with a wooden batten, or similar).

The horizontal screw is the idle speed; its conical tip raises the slide when it's screwed in (c/w). So:
  • back these both (i.e. on each carb) out so that they're not in contact with either slide.
    Now make sure that both slides bottom out in the carbs' bodies -- you can feel/hear this happening.
    If they don't bottom out, use the cable adusters (those on the carb tops for individual adjustment -- the one at the twistgrip cable exit for global adjustment) until they do.
    Ensure that the slides rise at exactly the same time (using Ed's 'thumb & forefinger' method)
    Screw in the idle speed screws, one at a time, until they just start to move their respective slides, then go another half-turn c/w.
    Turn in (c/w) the idle mixture screws (the down-angled, recessed screws just forward of the horizontal idle screws) all the way in (c/w) until they just bottom out; then back them out 1⅛-turns.
Now start the engine. If you can't get the idle down by turning the idle speed screws c/c/w (do it ⅛-turn each at a time) then there's possibly an air leak at the flange(s).

Finally, and paradoxically, the first thing the set is the float levels; that's another story. Have you done that? If not, come back and I'll post the link to help you do that bit.

G'luck!

PS: STOP switching the bloody slides around! The cutaways face the filters.... end of....!

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davomoto
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Post by davomoto » Mon Jun 20, 2011 10:38 am

Is there free play in the throttle cable? You should be able to twist the throttle an 1/8th turn before the slides start to rise!

Davo
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64 CB77
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naptown68superhawk
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yep.

Post by naptown68superhawk » Mon Jun 27, 2011 3:51 pm

Okay okay..... i stoped turning the slides around. i did the thumb and forfinger method. i set my floats but i will take that link if you have it. im just gonna do it again. cant hurt.... ready to ride..

e3steve
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Re: yep.

Post by e3steve » Mon Jun 27, 2011 5:05 pm

naptown68superhawk wrote:Okay okay..... i stoped turning the slides around. i did the thumb and forfinger method. i set my floats but i will take that link if you have it. im just gonna do it again. cant hurt.... ready to ride..
LMFAO! ☺
OK, Here's the story. I'd advise scanning over the entire topic, but the upshot is:
  • float height for a PW26 is 22.5mm from the carb's float bowl lip (recess on some types -- see p4 in that topic, near the bottom) to the floats' circumferences, float tang just touching the needle's spring-loaded plunger.

GG
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High rpm's

Post by GG » Tue Jun 28, 2011 8:48 am

Hey naptown,

I agree that high rpm's is often a lean condition. When I run my cb77 with the petcock closed, just before it runs completely out of gas, the rpm's go 'way up. If the gas in the floats is too low, it could be causing this.

The other thing that is VERY IMPORTANT is to make sure there is SLACK in the throttle cable. This is adjusted at the top of the carburator - there is a "cup" with a lock nut on it. You can loosen the lock nut, and screw the "cup" down into the carb body to give more slack. You must be certain that the slides can reach the bottom with the throttle is closed.

Good luck!

GG

naptown68superhawk
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yep did that too.

Post by naptown68superhawk » Wed Jun 29, 2011 2:35 pm

slides are as far down as they can go. not 100% closed engine side nor filter side. but the throttle cable has slack and is good working condition. i set the floats spent two hours with the carbs making sure evry little thing was just right. i read that the 22.5 mm is from the bowl lip. is that taking the gasket out and that lip or the edge of the bowl it self. mabey thats a stupid question. but either way im asking. i think i did it right. went to start it up and whhaaarrrararrrrr.FIVE THOUSAND RPMS.!!!!! aghhhhhhh. now im convinced it a vacume leak of some sort. should i tear apart the motor and start from scratch? should i give up hope of riding it this season and just do a complete overhall? im half tempted to go ahead and take everything apart and have the frame powdercoated like i want, say F**k it and go the whoile 50 yards. i got it from my wifes father he got it from his father.. so that makes it my daughters greatgrandpas bike, anyway he just found out he might have cancer. so i want to go the whole 50 yards for him. make it a beast once again. powdercoat the frame black and have the original paint buffed to perfection.

i digress...

shaolin slum

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