Hi all,
I'm very new to all this so please excuse my ignorance.
The short story is I recently purchased a 1973 Honda CB350G. Pre-purchase inspection showed compression in both cylinders was OK (170 PSI in the left and 190 PSI in the right) but I was told the left cylinder was not firing and it was not the plug. Therefore, I did the following:
1. Removed both plugs from the cylinders and kick-started the engine - I only got a spark from the right plug;
2. Swapped plugs to test the left plug in the right spark plug lead and got a spark - so both plugs are good;
3. At this stage I wanted to keep the inspection simple before having to remove the fuel tank so I opened up the breaker point cover (image attached); and
4. I started the bike to view the breaker points in action and only saw a spark coming from the left point (video link: https://www.youtube.com/watch?v=Hv-7_m3ERoU)
Once I removed the breaker point cover it seems like the left cylinder started to fire because the left exhaust was warm to touch. However, I also started noticing a terrible rattling/knocking sound (listen to about 8 seconds onwards in the video - I feel like it sounded a lot worse in person) so I cut the power and haven't ran it since.
Any thoughts or working diagnoses would be incredibly helpful. Thanks for your time.
~Dru
I'm very new to all this so please excuse my ignorance.
The short story is I recently purchased a 1973 Honda CB350G. Pre-purchase inspection showed compression in both cylinders was OK (170 PSI in the left and 190 PSI in the right) but I was told the left cylinder was not firing and it was not the plug. Therefore, I did the following:
1. Removed both plugs from the cylinders and kick-started the engine - I only got a spark from the right plug;
2. Swapped plugs to test the left plug in the right spark plug lead and got a spark - so both plugs are good;
3. At this stage I wanted to keep the inspection simple before having to remove the fuel tank so I opened up the breaker point cover (image attached); and
4. I started the bike to view the breaker points in action and only saw a spark coming from the left point (video link: https://www.youtube.com/watch?v=Hv-7_m3ERoU)
Once I removed the breaker point cover it seems like the left cylinder started to fire because the left exhaust was warm to touch. However, I also started noticing a terrible rattling/knocking sound (listen to about 8 seconds onwards in the video - I feel like it sounded a lot worse in person) so I cut the power and haven't ran it since.
Any thoughts or working diagnoses would be incredibly helpful. Thanks for your time.
~Dru