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My first project - 1974 CB360 K0
Craizeehair:
--- Quote from: Johnny4428 on February 09, 2025, 06:28:04 PM ---Just a thought when you removed the carbs laterly was there any fuel in them?
--- End quote ---
Yes, there was fuel in the bowls that needed draining
Craizeehair:
Had a little look tonight, carbs back off and gone through again, I’m now more than happy that they have to be ok.
I did check for spark again and found that I didn’t have spark on the right, I did briefly have spark on the right then nothing, so it’s back to square one and see what’s happening there. I’m sure there was spark yesterday? Not sure what could have happened to cause this whilst it was running and balancing the carbs, coincidence maybe?
McCabe-Thiele (Ted):
All it needs is a tug on a connector or something similar to loose spark.
Just needs checking starting with power from the ignition switch follow methodically through the wiring to the coil power, make sure the kill switch isn't causing an issue.
I had a slighly similar issue on my 400, turned out to be a poor soldered connection on the new fuse box from DS.
Craizeehair:
Well I’ve had fun and games in the shed!
The bike has been a nightmare to get running, a couple of weeks ago it started up and was running on the left cylinder only, whilst trying to figure things out I noticed that there was sparking at the engine mount from the cylinder head to the frame, as you can see in the picture.
I turned it off and started to try and figure out what was happening. A poor earth or something shorting were suggestions offered up.
I finally got a chance today to investigate, bearing in mind I haven’t touched the bike since so not sure what could have changed but it would not start.
What I found was that the spark plugs weren’t sparking correctly, if I held the plug tip just off the engine casing the spark would jump from the plug to the engine casing, touch the plug to the case and no spark. I had two spare plugs and tried them and the bike fired into life, both cylinders firing perfectly!
I checked for the sparking on the frame and there it was, so off with engine again, I checked earth strap from the battery connection, to the main earth at the engine bracket, the earth connection to the frame by the coils. I checked to see if I could see any wires that could be shorting anywhere but everything looked fine. I remade the earth connections and fired her up and the sparking at the frame has gone?
I’m completely unsure what the issue was as I found nothing obvious?
I have a couple of questions if anyone could offer up any advice
Does anyone have a suggestion as to what could have been causing the sparking at the frame issue?
Could that issue be the reason both new spark plugs were faulty?
It is running as good as it has right now but I’m not convinced I actually did anything to rectify a fault??
Bryanj:
Plugs probably failed because of the time you spent running incorrect mix whilst trying to get it right.
Sparking to frame has to be a bad earth connection, did you remove paint from brackets and casings?
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