Cb 550 ss spain

[murdock]

A long time I have worn marks on the throttle , many times I have run at different speeds and stopped to check the spark plugs , and many times I have been close to what works well throughout the range , but every time I go back out on it responds differently , because it is hot , because it is cold , because it is going to rain , because it is very early , etc , we all know that it is not a carburettor battery easy to remove , it is not like a Guzzi for example which you can disassemble a whole dellorto without removing it from the bike , I got tired of not being able to enjoy the bike , I will put back the original box to see how it behaves , and I will think if someday I try it again

[murdock]

Ok, I have all the jets saved, but the needles are still on the bike, I thought they had 5 notches, I don't remember now, maybe I'm confused with other needles I have at home.

[murdock]

My needles have 5 positions, they are 273004 I think they are the correct ones for the model 550 ss from 1977 with 069a carburettors, so I am confused, in which position should I place the clip, in the manual it specifies the second one, but does not specify whether to bottom up or top down

[deltarider]

Honda always determines the clip postion from top. Actually I am surprised the 273004 needle has five slots, so I have to investigate wherever I got that idea. Anyway, Honda is clear about the position: 2^nd from top. But... I don't think the issues you experience, have much to do with a jet needle being one notch higher or lower. But that's just an opinion.

[murdock]

Well today again my my motorcycle has let me down, I have replaced the original filter box with its original jets, 38 and 98, the original needle in its original diffuser, in the second notch from top to bottom 22 mm at the level of 1/12 float in the mixture, adjusted the points in the F, cleaned the spark plugs, and it does not run well,
At 1/4 throttle the grgrgrgrgrgr begins and it does not lift up until I exceed half the throttle, but they do not stop completely, it has improved a lot to 1/4, but nothing else, the carburettors were synchronized on the bench, both in total closure as in total opening, the only difference with the originality is that the air box inlet does not have a rubber elbow and that the exhaust silencer is a short megaphone with fiber inside
I have not sprayed the carburettors for leaks yet, but I know that in carburetor number 2 one of the four tank bolts is not tightening.
Could it be a spark plug failure? At idle I have loosened the cables one by one and in cough the change is heard, it may be that the battery is completely dead, I don't know what to do anymore, I thought everything would return to normal

[deltarider]

I've scanned all the posts here and - frankly - I can't believe the ignition was not mentioned before. Not until your last post, I mean. Ignition is where I'd start. Sparkplug noses can give a clue ofcourse, but here are some simple tests, if you happen to run the standard ignition.
Faulty condensers may cause arcing as shown in the vid: https://www.youtube.com/watch?v=t3cuvGVwnjI At the breakerpoints a bit of sparking is normal, excessive sparking or arcing is not good and can indicate a bad condenser. In this vid the left condensor (1+4) is bad, right condensor (2+3) is good.
Video: courtesy Ulf Penner
When you're at it, check none of the forked connectors at the breakerpoints accidentely ground to the plate. This grounding can be intermittent! Especially the 2+3 connectors are at risk, as they have a crosshead nearby.
To check the quality of the sparks, I have this simple tool: a copper wire which has an alligator clip on one end and is stranded open on the other.
Two ca. 0,4mm thick pieces cut out of an old credit card to be used as isolators.
Here is how it works.
Isolate breakerpoints as shown in the pic.
Attach alligator clip to the small center bolt of the breakerpoints, either 1+4 or 2+3.
Unplug plugcaps 1+4 or 2+3. You could unscrew the sparkplugs, but test can also be performed with reserve plugs.
Connect plugcaps to the sparkplugs that are out and are firmly (!) grounding to the engine block.
Turn on the ignition. Relax, both breakerpoints are isolated, so the coils are not taxed.
Simply move the stranded copper wire loosely over any part of the engine or frame (unpainted).
The effect will be a rapid serie of sparks very similar to when engine is running.
Verify the sparks are white or blue and not red.
Compare to the other set.
The advantage of the method is, you hardly use power and it will save you cranking the engine.
But above all: due to the stranded copper wire, there is this very rapid firing, which results in much more realistic sparks than by just holding a sparkplug to the block and crank one turn. The difference is huge.
How sure are you about the plugcaps? The coils secundary is around 14-15kΩ, so in total a circuit (either 1+4 or 2+3) will read 24-30kΩ if you have resistor plugcaps. If you read more than say 31kΩ, unscrew plugcaps from the leads to be checked individually. Ideally resistor plugcaps will read around 5-7kΩ. When over 8kΩ, replace.  BTW, do not run resistor caps and resistor plugs. When you have the choice, I'd prefer resistor caps. Realise that like sparkplugs, plugcaps have a limited lifespan, so when in doubt, replace.
Have you verified the advancer advances and retards smoothly?
I hope you're not offended, if I have posted what is all too familiar for you. Just ignore.

[murdock]

I would not be offended at all, what remains here will serve others
I usually check the ignition with the lights off, when a capacitor is defective, sparks are sometimes smaller than in the video
the plug caps are resistive 5 ohms and the ngk d7es plugs are no longer available, only the dr7es that are also resistive, that does not add up to 10 ohms, the sum of the 2 resistances is half of one, I will order a new set of spark plugs, I think I have a saved capacitor, I will review mine better, and I will try the method of isolated points, thank you very much

[philward]

Murdoch, I think D7EA are the correct plugs to work with resistor caps - they are available

[murdock]

d7ea will it be the replacement I can't get the d7es around here, someone is using them and could I confirm it?

[philward]

http://www.sohc.co.uk/index.php/topic,25753.msg235941.html#msg235941

[Bryanj]

D7EA is the replacement for D7ES

[murdock]

ok, thanks, I will buy new spark plugs and new capacitors, I could try to place the ones from my guzzi

[murdock]

Hello , does anyone have the reference number of any equivalent capacitor , or the value in uf ? Beru , Magnetti , Marelli , facet , etc thanks

[murdock]

found, page 88 of the honda manual, 0.24 uf +/- 10%
over 10 mega ohms

[Bryanj]

Its the temperature that can cause problems, it gets hot inside the points cover