SOHC.co.uk Forums > CB500/550

Partially Restored 74 CB550

<< < (37/45) > >>

davidcumbria:
heres a short run today.no more fuses blowing with rh switchgear off and a 15 a in place so its looks like that problem has been traced down. no throttle cables connected so i was quite pleased it started from cold easily on a closed throttle. seems to me its idling smoothly and picking up ok. this was after opening air screws another quarter turn to about 1.5. as mentioned dynamic timing and dwell could use abit of tweaking but i'll wait till ive got the throttle back. still some drips from the overflows so that wont be helping with the sooty plugs. think im going to take the carbs off and polish up the new float valves. getting happier. checked the revs were indeed 1000 with a tacho meter so my bike tacho is ok. it will be nice to have a right hand switchgear so ican stop having to short across the starter switch leads and have a kill switch and throttle  ;D

https://youtube.com/shorts/4YWwdzR1luc?si=-0d4UmGrUiFTgELr

deltarider:

--- Quote from: davidcumbria on January 04, 2024, 07:47:08 PM ---[...] It’s standard points ignitionwith new Few brand ( Japanese)points. 22A carbs with standard jetting 100 main, needle in the middle , 38 pilot ( maybe standard is 40 ). I adjusted the screws fro 1.25 to 1.5 turns out today and the idle/ pick up seemed slightly better. Dynamic timing showed it to be about 2 degrees retarded ( 7? degrees) so I’ve slightly adjusted that. The dwells were close but not exactly the same so I can work on the points set up  a bit.

--- End quote ---
You can compare yours to the standard 022A in the updated overview below. Even if the jet needles are one step leaner than standard, I'd leave the carbs alone for now.
As far as the ignition, a few remarks, if you allow me.
Realise that advancer is a somewhat misleading term. Retarder would have been better, because the thing is mainly there to facilitate easier starting. Have a look at the advancer below. The yellow mark indicates 5o BTDC. Easy starting is then guaranteed. But my bike starts just as easy at 8o BTDC. I do not strive to have it spot on 5o BTDC. I concentrate on a correct timing at full advance of around 30o instead, from say 2800 RPM on. Full advance is indicated by the two marks, one blue, one green. They are 3o apart and I'll come to that next.
I've always used genuine Honda parts and on my bike, they are by TEC (TOYO), but things work just the same with Hitachi parts.
Out of curiosity I once experimented with setting things exactly spot on and then varied the dwell.
With timing static set at exactly 5o and a dwell of exactly 49o (= 0,3mm gap), full advance would be at the first full advance (blue in the pic) mark, 28,5o. When I changed the dwell to 46o (= 0,4mm gap), full advance would be at the second full advance (green in the pic) mark, 31,5o. I should add, this test done was on my bike only and I am sorry to say I have not completed the experiment by repeating this for 2+3. I was quite impressed by the accuracy of Honda parts and even more when I choose the middle: a dwell of 47,5o (= 0,35mm gap) which not only resulted in a full advance right between the two full advance marks 30o but also, as a bonus, having all components in the middle of their adjustment range.
Using OEM parts, having everything in the middle of the adjustment range, seems to be a good starting point. With aftermarket parts, it's anybody's guess. When I helped a friend who had a Daiichi plate and breakers, I did not arrive at having components in the middle of their adjustment range, when I choose the middle. I'm not saying Daiichi parts are therefore bad, they're are different. In the past I have suggested that Daiichi in the US must be Chinese imitations of the Daiichi sets we have in Europe which were made in Japan. The reason is that I know quite some riders here, that have satisfactorily results with them. As said: the US market is another story. I'm curious to know how your breakerpoints will do.
I always have my ignition 2-3o more advanced which results in a better throttle respons (driveability) but that's up to anyone's liking and it could also be fuel related.
I can recommend to begin simply with a feeler gauge when setting the breakerpoints gap. If you have a dwellmeter, I'd use it. Then you can set the breakerpoints dynamically and also check the dwell remains constant and does not wander when RPM changes.
Checking the timing is best done using a strobe, but, I would not attempt to adjust the timing dynamically. Plates will move about and it can become a frustrating experience. To avoid the hassle, I check at full advance. Then stop the engine and make the needed adjustment, start engine again and check again at full advance. You may have to stop the engine again for a further adjustment. This has worked for me. Just accept the timing @ idle it will result in.
(Re)setting the gaps comes first, because it is there, where the timing begins to deviate from the ideal. As a matter of fact: usually just resetting the gaps (dwell) is the only thing you have to do, to arrive at the correct timing again. Makes sense, the plates are well fastened and won't wander. At least not that I have seen.
Your ignition needs to be tuned a bit, but - listening to the engine now - I'm sure it will run beautifully. It's a wonderful bike.

davidcumbria:
Thanks , it’s going to be several days before I can get back to tuning but plenty to chew over there.

davidcumbria:
Almost fully assembled now. Found this in the bag with the rear chain guard attachment bolts and fittings. Can’t remember or see where it goes…..

Oddjob:
Can't remember ever seeing that on a 550 Dave.

Navigation

[0] Message Index

[#] Next page

[*] Previous page