SOHC.co.uk Forums > CB500/550
Partially Restored 74 CB550
Seabeowner:
--- Quote from: Bryanj on December 15, 2023, 05:11:50 PM ---I proved to an apprentice that i could be as accurate with a feeler gauge as he was with a dwell box, it is down to experience and practice.
All the 500/550 are not the same, there are at least 2 different advancers with different advance curves, when i was in the trade i NEVER had a bad set of daichi contacts OR condenser, now its different due to change of factory and QC.
--- End quote ---
Seems any old numbers may have been superseded but whatever, I have three different parts lists and manuals for four variations of 500 and 550 and they are now all called up as the same so Delta has a point.
The most important thing is that the spark comes at the right time in the cycle and I believe that they are all 5 deg BTDC at idle and 25 deg fully advanced. Also there needs to be enough time to (for a better word) energise the coils. Presumably dwell plays a part here but of course the time will in change inversely according to RPM.
And anyway I'm grumpy as I just sheared a bolt off in the sump of my 500 and it was not in anyway tight. So I'll be laying underneath it tomorrow.
davidcumbria:
Thanks for the heads up. I’ll post some photos when I get stuck. Christmas duties going to be getting in the way of my fun in the garage a fair bit 😉😅
McCabe-Thiele (Ted):
On my 500 I bought some pattern 550 bar switches from Germany as they were what seemed a good price.
As you will see from my 500 project my wiring took me a while to sort it out as I had the wrong bar switches- I did a spreadsheet to help me figure out the wires in the bowl. I will PM you a copy of my wiring spreadsheet Dave - obviously there might be a few differences between the 500 & 550 but you might find it's helpful in terms of what colours are used for what.
I found the horn & the starter solenoid appear to work in one of two ways either the button was an earth or it supplied power looking at the internal switch wiring. My findings for my switch gear are at the bottom of the spreadsheet.
davidcumbria:
A bit of a jump out of sequence but I recently came across this thread on the us forum which has so much of interest about the set up and design characteristics of these bikes. It explains about the ignition and cam timing and flat spot issues. I reckon it should be a sticky in the tips and tricks section. Apologies to those who already are very familiar with it.
http://forums.sohc4.net/index.php/topic,7401.msg67251.html#msg67251
deltarider:
That socalled 'flat spot' is a consequence of the design (think dimensions and in particular bore x stroke) of a 4 cylinder 500/550cc engine. I have read an explanation in a german motor magazine by an engineer over 40 years ago. Also I remember an article on the same subject by a Dutch engineer, which has later been published in a book. In principle this phenomenon can't be helped. The good news is, that it is only noticable when you accelerate from midrange RPM without shifting down. When you accelerate hard from a stop and do not upshift unless near 8000 RPM, you will not notice a flat spot. Anyone can try this out for himself. The Honda CB500/550 offers two bikes in one: a very conversational - if that's the correct word - one, that even a child or an 80 year old can ride and a sporty one, when revved. Many Honda products, including cars, have this characteristic.
Much in that thread you've referred to, is questionable and many claims have remained unproven. From time to time it has therefore been met with criticism from some, including yours truly.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version