SOHC.co.uk Forums > CB500/550

I need a carb sync - Anyone in North London?

<< < (4/9) > >>

michtag:

--- Quote from: K2-K6 on August 13, 2020, 08:00:26 PM ---
It'll be interesting to see if there's any improvements by changing the plugs,  but think there's potential circumstances under which that would indicate another error.

--- End quote ---

Well, there's only one way to find out 😁
Still, it would make sense to have the "correct" resistance all along the line. Some time ago I checked all my coils and leads and changed the caps as a consequence as they seemed to offer too much resistance (and they gave 4 different readings). Did I notice a change? Not really, but I think the problems I have been having are a sum of little "off" things, so I am trying to chip at them all, one by one. It's a process of elimination.
Once I get the timing sorted with a strobe light and the carbs synced I'll see if the idling gets consistent. If not, I'll keep poking around...

michtag:

--- Quote from: jeremypeachey on August 13, 2020, 08:17:22 PM ---Michele, a long shot, but is the petcock gauze clear. I had erratic fuel flow and cleaned it in vinegar and very gentle brush with an old toothbrush. Then a column of water from a tap would pass freely through it uninterrupted.

I find even when all clean, fuel often only manages to flow through one pipe at a time, so eg from empty, carbs 1&2 and 3&4 don’t both get full flow at the same time, and maybe a slight restriction could cause flow to fluctuate.

As I say very much a long shot, but quick and easy to check, and always good to know it’s ok.

--- End quote ---

Hi Jeremy, that has been one of the many things I have tried in the past. I have a new petcock filter (the one inside the tank), but I must admit I have not opened the petcock as it's not one of those that can be opened via a couple of screws. Petrol flow seems fine and constant though (I have observed while filling a bottle straight from the petcock) and I have a new fuel line, with no kinks and no inline filter.
I have therefore eliminated this as a possible source of my problems.
Cheers
Michele

JezzaPeach:
Ah ok, different to the 500/4 too.

paulbaker1954:

--- Quote from: michtag on August 13, 2020, 01:25:39 PM ---Update of the day:
Just before thunderstorms hit (although it's still well sunny here) I decided to have a check at the timing.
-Points gaps were at 0.3mm and 0.35mm, so I made them both 0.3mm now.
-Static timing is spot-on for 1-4 and 2-3

I have tried using my strobe but the idling seems too unstable that I am not sure about anything, so I have not tried to adjust anything. I will try again just to see if I notice it being too far advanced at higher revs, but from first examination it does not look that way. It may be that it advances too soon though. I have tried in the past to use different spring combos in the advance mechanism but never really solved anything, so I reverted to the original setup (I was probably jumping the gun anyway).

Here's a video I shot today, just to give you an idea of what it sounds like when idling. Note that unless you see my hand on the throttle or idle screw, she's doing everything else by herself!

https://youtu.be/ESx_E8mv2vM

Carbs are standard PD46A with. standard jetting, This may not be ideal for the Delkevic 4 into 1 the PO put in, but it should not give problems when idling

As suggested above, I will try spraying carb cleaner on and around the inlet manifolds to check for air leaks there, but I have new manifods and o-rings so I doubt it will be that.

--- End quote ---

This def sounds like a fuelling issue not an electrical issue. As I said check for air leaks very carefully

Bryanj:
PD46, just about guarantee the pilot jets or pathways are blocked

Navigation

[0] Message Index

[#] Next page

[*] Previous page