Misfire With Tach and Speedo Issues

[Big_Jim59]

I have searched the forum for any similar issues and have come up short.

I took the bike out today. I have been riding it a bit more aggressively now that I have gotten used to it and I started to notice that the tach and speedo are prone to jump around. Then the bike began to misfire.

When misfiring both tach and speedo needles rise but not with engine RPMs. It acts like it is running out of gas and I would think it is fuel related except for the wild antics of the clocks. Has anyone ever experienced anything like this before?

[Big_Jim59]

OK, I am going to reply to my own post. After extensive examination of the wiring harness and all its connectors and after replacing the questionable battery and cleaning all ground points and after a careful test ride and evaluation UI have come to the conclusion that I actually have two problems that are unrelated. The misfire was caused by low fuel. Since I am new to this bike I do not know at what point the bike will go on reserve. It seems that this was the issue. After a fill up the mysterious misfire went away. The tach and the speedo are another matter. They still act up. I think they are just junk.

[Big_Jim59]

I have been doing more work on the B6. The tach and the speedo issues were caused by my too thin mount made of sheet metal. The vibrations were taking a toll on the electrics and causing the wild antics. The vibration finally broke the mount and I re-manufactured it using heavier supports. Problem solved.

The cutting out was due to low fuel and a dodgy vacuum petcock. I pulled the petcock and tested it using my hand pump vacuum creator. It showed the spring was not stout enough to hold the petcock closed so I added a small helper spring that did the trick. That problem is solved too.

Now I am on to the carb set up. The bike starts and run fine with no choke. It runs out well but only gets 30 mpg. I have to do a major tune up including setting the valves, replacing the air cleaner, checking float height and jets.