Topic: Raise needles in 1977 CB550 carbs

[jorwesflow]

Other than carb #2 (because there's no adjuster taking up space), it's impossible to get the little link arm off the pins to be able to pull the valve/slide out. I need to raise needles a notch. what's the trick here? And what exactly does the adjuster screw do? Is that not effectively raising the whole valve/slide and subsequently the needle as well? Is that the answer for 1, 3 and 4 to just adjust the screw? And then just raise the needle for #2?

[martin99]

Have a look here. Should be helpful.

http://forums.sohc4.net/index.php?topic=71245.0

 

[jorwesflow]

Have a look here. Should be helpful.

http://forums.sohc4.net/index.php?topic=71245.0

 

Problem is, this guy took photos demoing how to do this on carb #2, which I stated is the only one that I have no trouble getting the link arm off. So his pictures don't help. The other three carbs with the adjusters on them are impossible to have enough room for the link arm to slide off. One post in the infamous "Pods Thread" says this:

Yes, you can get the needles out without removing the carb banks.  You need to remove the screw that holds the lever on the throttle shaft, and then lift the lever and slide up as high as possible in the carb, then slide the lever off the pin on the slide.  #2 is easiest as there is no adjuster in the way.  The others require a little "manipulation" to get them off.

What he means by "manipulation" I'd like to know. Because I have manipulated all I can without bending anything. I'm about to just pull the carbs apart...

[DaveBarbier]

I personally don't like the method in that link. I've tried it and it's not easy. I don't separate the arm. Remove the set screw that holds the throttle linkage to the arm (just so the arm isn't sprung anymore and you can move it freely and easily). Then there are two screws that hold the slide arm to the slide. You can actually see them in your picture. Down the slide you can see two small dark screws on a plate. Just get a small (and thin) screwdriver and press firmly and unscrew. Make sure the driver feels like it fits snugly in the screw head, don't want to strip it. I put a file to a screw driver to make it more of a blunt tip and not a sharp point. Seemed to help a lot. It's kind of frustrating because you have to manipulate the arm back and forth to actually get at those screws but it's not too hard. Once you get those screws off just lift the arm and then you can lift out the slide. Just keep each slide with each carb. And note which orientation the slides are in the cylinder. With the angled cutaway facing the airbox.

For assembly it's best to use a magnetic screwdriver so you can lower those small screws into their home and screw away. You can make any screw driver magnetic, just do a YouTube search.

This isn't my method. I found it somewhere on this site but can't remember where.

But to answer your other question, yes the needle will raise when you adjust the slide adjuster just because it's attached to the slide, but that's not how you do it. You raise the needle from the clip positions. You want to raise only the needle when adjusting the needle.


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1978 Honda CB550K

[jorwesflow]

Dave, I think you hit the nail on the head. I did attempt to do what you said before you had posted. Unfortunately I did strip one screw because I failed to file the screwdriver head like you said to give it a better fit in the screws. After I stripped that screw I decided to to just pull the carb bodies apart off the throttle shaft. I didn't want to risk ruining any more screw heads. With the carb bodies off the throttle shaft I could then pull the valves right out. That allowed me to get a better grip and get those stubborn screws off the plate and give access to the needles.

But to answer your other question, yes the needle will raise when you adjust the slide adjuster just because it's attached to the slide, but that's not how you do it. You raise the needle from the clip positions. You want to raise only the needle when adjusting the needle.

I'm an idiot. I realize now that those adjusters are to synch the carbs. Tomorrow's project...

[DaveBarbier]

Oh too bad, if I was only quicker on the reply! But that's ok, worst case you learned how to dismantle the rack. I think I'm right in saying that all the "Phillips" screws on these bikes aren't Phillips at all but rather JIS. Most people use Phillips drivers and are fine but many times it strips the screw. Phillips drivers are designed to slide out (or cam out) of the screw head once a certain torque is applied so they're not the ideal tool to use to try and remove these screws. You end up having to push super hard to avoid the cam out. I was learning about Phillips vs JIS a while back. Super interesting and boring as hell all at the same time. Not sure how that works.

Good luck on the rest of your carb stuff.


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1978 Honda CB550K

[jorwesflow]

I think I'm right in saying that all the "Phillips" screws on these bikes aren't Phillips at all but rather JIS.

Wow, this just blew my mind. Never even knew what JIS was. Just googled "JIS vs Phillips" and finding great delight in the results. I think I'll buy a JIS driver kit now. Or maybe I already have one and didn't realize it. I have stripped many a "phillips" screw on my Hondas through the years. If only I knew.

Funny enough, I think I need to raise the needles one more notch. I had a flat spot that got a little better after raising one notch, but I can still sort of feel it while riding it out today. I think I'll try your method with a JIS driver, or file a Phillips down. Might not even have to take the carbs off of the bike this time.

[DaveBarbier]

Cool, try it out. Worked for me.


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1978 Honda CB550K