CB550 K3 custom project

[thomaspigeon]

Hey,

So I tested the plug caps + coil resistance

Plug caps are at 4.5/ 5K ohms so that should be ok

Coil resistance is at 25K ohms for both so all good on that side!

I’m waiting for the new spark plugs to arrive now. Should be on Thursday.

Now I figured another odd thing with the carbs. I tried to sync the sliders with drill bits. But when I open the sliders fully, I always have a gap with carb #2 and #1, the 2 others looks fine. Could you have sliders lifting up at different speed? I should probably create a topic about this.

Thanks
Tom 

[McCabe-Thiele (Ted)]

Okay I'm new to this forum but did you check the sliders before you reassembled the carbs on the inlet manifold. It sound to me as though you have sticking sliders near the top of the travel could be muck in the carbs or check the links at the carb top where the springs & little T shaped rods are.

I did the drill bit initial setting on mine and they all fully opened from the throttle action. Is there an issue with the two cable adjustments preventing the throttle from fully opening ? Are you sure you put the T shaped rods in the right way up they seem to act like a pushrod for the throttle movement?

[thomaspigeon]

Actually I start to have a massive doubt about my multimeter reading. I’m pretty bad at it

I attached a photo of the reading of the coils HT

What are your thoughts?

@macabethiele I’ll have a look tomorrow at this

[McCabe-Thiele (Ted)]

Actually I start to have a massive doubt about my multimeter reading. I’m pretty bad at it

I attached a photo of the reading of the coils HT

What are your thoughts?

@macabethiele I’ll have a look tomorrow at this

Have you checked the battery in your Multimeter I had to change mine after a couple of years use .

Are you getting a good fat visible spark when you check it with a loose spark plug ? Don't forget you get the extra sparks on the other cylinders as there is no distributor fitted.

[thomaspigeon]

@macabethiele I found the culprit, it’s the arm set link that got more play on carb on 1 & 2 not sure if I’ll change it for the price!  https://www.cmsnl.com/honda-cb550f-super-sport-550-four-1976-usa_model467/arm-set-alink_16018323004/#.X1oSxyV4WEc

@julie, I’ve set up the float height following your topic but its overflowing quite a lot on 2 of those. I’m really desperate with those carbs. They are from a cb550 f1 so the height should be 22mm and I made sure both sides of the float were level.

Maybe my overflowing pipe too low for some reasons as I’ve seen they were slightly bent, all the bits inside are new so that can’t be this

The carb reference is 069A Keihin

[thomaspigeon]

I figured out the pin for the floats are getting stuck...

I’ve attached some photos to make sure I do the things right

[McCabe-Thiele (Ted)]

As long as the bottom clip is in the right position this prevents the float from dropping too far down and jamming the valves open- on my Carbs the spring clips span across the width of the bowl stopping the float from dropping too far down Yours should do the same thing if you have them fitted correctly for your carb.  When I had my bottom clips in position with no bowl fitted they stopped the floats from descending too far and allowing the needle valves to drop down too far and jam open.

As regards the carbs fully opening:-
As long as you have the little spring & plunger thing in the right position you should have no trouble with them opening fully. I see no reason why you should ever need to replace the levers as shown in your link unless something is missing. There is what I would describe as a fixed half hip bit that's black in colour and fixed - you then have the small plunger with the wide end facing the fixed cup, then the spring then the lock screw & nut etc. When you fit the throttle link ball into the slot the two halves form a perfect support either side of the ball bit! I cant imagine you ever having enough wear to justify replacement of the link.

[Nurse Julie]

I'm just trying to get my head round your photos, something doesn't look right 🤔🤔🤔 I will find a float in a bit and have a look.
Also, if you have fitted all new brass ware, unless they are genuine Honda, there is no guarantee the float vales are shutting fully in the seat.

[thomaspigeon]

@macabethiele, the slider open fully but I have a gap that I do not have at the bottom. Im  pretty sure their is more play on 1 arm set as I can feel it but I do not think it is a big deal. If it is, I will change them.

So the float looks upside down for me too but they were that way when I opened them (it does nott mean it is right but they are going the same way on cmsnl)

I managed to have them not leaking with a higher float so the valves are sealing properly

I tried to change the shape of the Float tab were the valve is Seating on to make sure the pin does not get jammed. But it does not work...

[thomaspigeon]

Thinking the spring in the float valve maybe too stiff and prevent the valve to close properly

[Nurse Julie]

So let's clarify. Your bike is a CB550/4 K3 but instead of the standard PD carbs fitted to that model, you have 069a's fitted. Is that correct?.

[thomaspigeon]

Yes indeed. I don’t know why or what happened in the past to have this fitted

[Nurse Julie]

Yes indeed. I don’t know why or what happened in the past to have this fitted

Not too unusual really, PD's are the work of the Devil and some owners changed them, and the manifolds, for the 069a's. I can't see why the float needle pin won't depress. Can you pist a pic of the carbs laying down flat, with the floats facing uppermost?.

[thomaspigeon]

I’ll make 1 post per photo so you can have some good quality

[thomaspigeon]

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