Topic: '77 550K - How do I adjust carb needle height?

[youngerthanmybike]

I have the PD46A carbs, and I'd like to be able to richen the mix a little so that I can run without my airbox cover on, but I have no idea what I need to do to get at this needle or how to adjust it. Can somebody give me some direction or some pics? I know what it looks like via the parts fiche, but that hasn't helped too much so far. How much of the carb do I need to take apart to get at it? Do I go from the topside or from the bottom? Thanks-

[Sporkfly]

Open the top cover, look down into the carbs and you'll see two screws and there's a spring somewhere in there... I don't remember exactly, but it's pretty easy once you have the top cover off looking at them. From there you'll find an E-clip which can be raised or lowered on your needles.

Edit: Maybe when I get home from work I can take some pictures as my carbs are off ATM.

[youngerthanmybike]

Anybody else?

[edbikerii]

Look at the "Needles" link in my sig.

Anybody else?

[mmtsquid]

Remove tank
take top "cap" off carbs.
looking down in there, you will see 2 screws - remove them
grab the "arm", and pull it up
remove slide and needle
use pliers and pull the clip off of needle - move clip down to richen, up to lean.
put it back together, and repeat 3 more times.......

Have fun!

[youngerthanmybike]

Thanks a ton guys! That makes much more sense than anything I've found yet. I didn't want to take too much apart on my carbs without knowing for sure what I was taking apart, as they are running pretty decent right now.

edbikerii- I would have never found that in the middle of that massive thread.... I saw the thread before, but I didn't even open it because I'm not doing pods. Hopefully this thread will be easier to find for whoever else is doing searches.

[Johnny5]

You might need to go up a size or two on the main jets. This should be your first carb adjustment before messing with the needles.

[edbikerii]

Yes, there's a lot of VERY useful information in that thread from various members here.  I've decided to stop having to search for it myself whenever someone asks, so I've added those two posts to my sig.

I'd be willing to bet that you won't realize any improvement through adjusting the needles, plus it is a bit of a pain.  On the contrary, you'll probably need to go up a couple sizes on your mains like Johnny5 said.

Good luck,

Ed

Thanks a ton guys! That makes much more sense than anything I've found yet. I didn't want to take too much apart on my carbs without knowing for sure what I was taking apart, as they are running pretty decent right now.

edbikerii- I would have never found that in the middle of that massive thread.... I saw the thread before, but I didn't even open it because I'm not doing pods. Hopefully this thread will be easier to find for whoever else is doing searches.

[moham]

but I didn't even open it because I'm not doing pods.

if you're not running the stock airbox and you're not running pods, how are you cleaning the air?

[Johnny5]

but I didn't even open it because I'm not doing pods.

if you're not running the stock airbox and you're not running pods, how are you cleaning the air?

Dont nose hairs do a good enough job?

[Sporkfly]

but I didn't even open it because I'm not doing pods.

if you're not running the stock airbox and you're not running pods, how are you cleaning the air?

He's leaving the box in and taking the snorkel off from what I understood. To each their own I suppose?

[youngerthanmybike]

I assure you- I have a hearty set of nose hairs. 

Yes, I'm planning on doing something different with the stock air box without the tuning headaches of pods. I haven't totally made up my mind yet, but I'm sure I'll keep you all posted somehow.

[moham]

Dont nose hairs do a good enough job?

At this point in my life, most of the hair I have left is concentrated in my nose...

[Johnny5]

I dont understand what's so difficult about pods. Be patient and work on one adjustment at a time. Got my bike dialed in in one weekend.

[mmtsquid]

I kind of felt his pain on pods - but I suspect most of my problems were from using cheap k&N knockoffs.

Younger - these gents are right about probably needing to go up a jet size or two.
Jets are pretty cheap - if you have to order them, get 2 or 3 sizes at the same time - you may not need them, but sure as you only order one size, you will need something different.  And have to wait again!

[edbikerii]

Agreed.  As you'll see in that thread on jetting (in my sig), waiting (and paying) for UPS is the biggest drawback of re-jetting.  Try to find a good local bike shop that has take-off jets.  That will save you a lot of time, and maybe even some shipping costs, but the jets will be slightly more expensive.

I kind of felt his pain on pods - but I suspect most of my problems were from using cheap k&N knockoffs.

Younger - these gents are right about probably needing to go up a jet size or two.
Jets are pretty cheap - if you have to order them, get 2 or 3 sizes at the same time - you may not need them, but sure as you only order one size, you will need something different.  And have to wait again!

[youngerthanmybike]

Actually, the main reason I wanted to know was so that I could play around with it and see how it acts differently. I keep hearing people say to just adjust the needle height, so I figured I oughtta know how to do it.

I can tell my bike gets more air when the cover is off, by the way it sputters more in the midrange rpm, so I'd like to see if I can compensate for that by needle height. I want to understand why it does what it does so I can tune it myself instead of just asking everybody else what I should do. I want to get it dialed in at the stock settings so that when I do change things, I know what it should feel like.

I'm glad to keep talking about my bike, but I want you guys to know what I've got and what my plans are. I just finished rebuilding the engine- cylinder hone and new rings. I also did some mild porting ala Hondaman and from a few other threads on here. Mainly just cleaning things in the head up a bit. While at it, I dropped in a 650 cam, so on the whole, my bike should already be getting more air than it did before the rebuild. I am waiting on a Kerker 4-1 pipes to show up, but I'd like to have a baseline established before I start tuning for those. I ordered one set of extra jets, but it was just a shot in the dark guess on size. Stock size for my the carbs I have is 90, so I ordered 105's. I don't want to put them in until I have the pipes on, as I feel it might be too much of a jump right now.

I'd love to someday do pods. Pods are not an answer to my problems. I don't want a race bike, I want a quick weekend cruiser that I can ride to work without being uncomfortable. I'm not against them, I think they look great. Long story short, I can't afford it right now, especially because if I'm going to put them on, I'm going to do it right. For me, that means K&N filters, and another retune.

Thanks a ton for your input, it is definately helpful. I haven't checked about a local shop with jets, the one that might actually have them is about a 30-40 drive to get there, and it's in a direction I rarely go, so it's almost easier to have UPS drop them off.

[robermcm]

Hap (forget his handle) helped me with removing the needles from a 75 cb550k with minimum fuss.  Not sure if your 77 carbs are similar.

Yes you can adjust the needles without removing the carbs.  I prefer to do it that way.  You just need to take off the gas tank so that you can access the carb slide top covers.  It helps to have a right angle phillips head screw driver to get to the screws on carbs 2-3 which are sort of under the frame, a chapman set works great.  I do one carb at a time.  You have to take off the screw that holds the actuator arm to the throttle shaft.  It has a metal locking tab you have to bend out of the way first.  Now you can lift the slide up and down.  Next you have to remove two phillips screws down inside the slide to disconnect the slide from the actuator arm.  Be careful not to drop the screws.  The screws inside the slides can sometimes be pretty tight.  I give a tap on the top of them using a wrench on the top of the screw driver handle to help break them loose.  You don't want to strip them.  The tricky part is that the slide now needs to be rotated 90 degrees so that the slot in the slide lines up with the actuator arm plate.  Once that is lined up you can lift the arm all the way out of the slide.  Lastly you just need to lift out the slide and make your adjustment to the needle.  Putting it all back together is made easier by using some electricians tape on your screwdriver to hold the slide screws while you try and tread them down inside the slides.  It may sound like a hard job but it isn't really that bad once you get started and it starts making sense.  Just go slow and take your time.  Once you get the hang of it you can do all 4 carbs in about 30mins.  Making adjustments to the slide needle make that biggest noticeable change to your mixture.  They affect your mixture all the way from right off idle to almost full throttle.  Good luck.
Hap

[mmtsquid]

Younger - Here's something to keep in mind as well............
Don't be concerned with how your bike acts at a given RPM when trying to dial in air/fuel ratio.
What you should be concerned with is how your bike acts at a given THROTTLE position.
Throttle position (1/8 travel, 1/4, 1/2, 3/4, and full) and plug chop tell nearly the whole story about what's happening in your combustion chamber.
Get some masking tape (1 piece on starter button assy, 1 piece wrapped around right grip, close to starter assy.) and make graduation marks telling you where those different throttle positions are.
Warm the bike up, and then get busy - hold the bike at 1/8 throttle for a few seconds, then kill it with the switch.  Take out your plugs and see what they say.
gray/white - lean at that position
blackish or oily - rich at that position
Tan - perfect!
Rinse and repeat for each throttle position.
When you have ALL of that data, you know what needs adjustment and more importantly, what DOESN'T.

Have fun!