Topic: 1975 CB550 Needle clip position

[eprovenzano]

I'm cleaning a set of carbs from a 1975 CB550 stock airbox and filter.  When I pulled the needle I found the clip is on the top notch, clip #1.  To me this is very lean, the plugs show slightly lean as well.  I've looked, but have not been able to find a definitive answer as to the stock location of the needle clip.  I've seen 2, 3, & 4...  So what is the stock needle clip position, and now that these bikes are 40 years old, is anyone running anything other then stock?

[Deltarider]

What is the stamped on carbnumber?

[eprovenzano]

I'm at work right now, but as soon as I get home I'll check and post what I find.

[mrfish2]

From this picture I think it means the 4th groove from the top for K bikes and 2cd groove for F bikes. Someone correct me if I'm wrong.

[eprovenzano]

Thanks mrfrish2...  That is exactly what I needed to know.  I need to verify the carb, 022A or 069A, and then properly set the clip and air/fuel screw.  I can't go by jet sizes as its running a 38 slow jet and 100 main jet.  This and the clip position tells me someone was in the carbs at some point in its life...  I "think its a "F" model (but I will verify), and stock would have been on the 4 notch.  Since she is 40 years old and if its an F model, I think I'll set the clip to the 3rd notch. In my mind this will help compensate for any engine wear, lose of compression, but will richen it up enough to run effectively and give her back some top end. 

Personally I've only ridden it a few times, but to me it was a little flat on top... I'm used to larger displacements so at the time I didn't think much about it... now looking back I think it was too lean causing the the top end to plateau.. 

Oh BTW... love the quote "It's a little motor and likes having the tits revved off it"... classic

[mrfish2]

Looking back at the pic I'm not sure how accurate it is now, because it shows the stock idle jet for the earlier K models is a 40, when in fact it should be listed as a 38. Anyway, I think you should be fine at starting out at the 3rd notch and going from there. Get a bunch of new spark plugs and start doing plug chops to dial in those clip positions.

Also, the 022A carbs stock jet sizes are 38 slow and 100 mains, so yours are correct.

[Duanob]

Remember everytime you get into the sldies and needle area you will have to vac sync again. Don't forget to clean the needles with very fine 0000 steel wool.

[eprovenzano]

Looking back at the pic I'm not sure how accurate it is now, because it shows the stock idle jet for the earlier K models is a 40, when in fact it should be listed as a 38. Anyway, I think you should be fine at starting out at the 3rd notch and going from there. Get a bunch of new spark plugs and start doing plug chops to dial in those clip positions.

Also, the 022A carbs stock jet sizes are 38 slow and 100 mains, so yours are correct.

Thanks, I was doing more research and can say for sure its the CB550 "F" model with the 022A carbs.  It's nice to know its still running the stock jets, but the different clip position has me puzzled. Oh well what do you expect for something that's 40 years old...   

Remember everytime you get into the sldies and needle area you will have to vac sync again. Don't forget to clean the needles with very fine 0000 steel wool.

I was just looking at the procedure to sync the carbs...  Before I get too far, I'm going to check the valve specs too. With everything else apart, its easier to do it now than later.

[mrfish2]

Remember that a vacuum sync is the LAST thing to do. Set timing, tappet clearances, cam chain tension, basically the entire 3000 mile tune up FIRST.

[Deltarider]

Thanks, I was doing more research and can say for sure its the CB550 "F" model with the 022A carbs.

What made you so sure?
All CB550F models had 069A carbs, the 022A were on the CB550K(0) and CB550K1 models.
From the pictures I've seen, yours looks like a K1 model.
But why don't you verify by comparing your engine- and framenumber with the engine- and framenumbers listed in the various CB550 Parts Lists? You'll find them all here: http://www.honda4fun.com/materiale-documentazione-tecnica/parts-list/parts-list-cb550
You'll find the engine-and framenumbers listed in the first pages of every Parts List.
Then this: there's  a lot of needle fiddling going on in this forum (as there is floattang bending and syncing btw). People believe that all actions described in manuals (sometimes copied from other manuals describing totally different motorcycles) apply to their bike. This is not so. Some things were better left alone as some models hardly ever have issues with some items. My suggestion would be to have the needles in the position that Honda suggests and then leave them there, at least for a wile. You don't wanna go plugchopping and opening up the carbs at the top every time which will mean you have to sync them again and again. The 38 slow jet and the 100 main jet are OK for your model. You could start by adjusting the airscrews a little bit and see what that does for driveability. Testride.