Engine ground strap

Currently I'm working to square away the wiring on my 69'. For the most part it's not bad but mice have nibbled away most of the cloth covering and what's left is soaked with oil so I cut it off too so I'm replacing a few wires that have been rubbed thru and a couple of connectors that look ragged but am about ready to go back together with some new snakeskin and assorted hardware to (hopefully) upgrade things a bit. To that end, I remember seeing a picture here, I think in was in a thread about headsteadys, of someone's bike and it had a super-duty woven copper ground strap going from the engine head to the frame. As I recall it attached to headsteady mountings on both ends. My question is whether such a substantial ground is needed. If so, I'm at the point to add one, but if not, well, there's enough else to do without making more work. I plan to install a Pazon surefire when I get to that point and plan to ground it by running a wire back to the rectifier.
Hope this isn't a controversial topic, but I though it best to do a sanity check with the minds here. Thanks.

The Pazon I installed called for running its ground wire to the tab on the mounting bracket that the coils are attached too.
Works fine for me.

Bob

sidreilley said:

My question is whether such a substantial ground is needed. If so, I'm at the point to add one, but if not, well, there's enough else to do without making more work.

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Although desirable, in my opinion a braided ground is strap isn't entirely necessary, as any properly connected wire would do.

What I have done is to run a loose length of slightly heavier gauge red wire between one of the 5/16" headsteady-to-head allen screws, and one of the coil bracket-to-frame mountings to act as the ground wire. I also use a coil bracket mounting for the coil ground wire connection.

A heavy gauge ground is not required unless you have electric start. The ground does need to be durable so the vibration does not break it. Ground wires attached to the head often break because the vibration is severe up ther. I recommend omitting the ground wire at the head and running a new wire from one of the oil filter mounting bolts up to the battery ground near the battery. There is not nearly as much vibration present back at the rear of the cradle so the wire doesn't tend to break. On bikes with electronic ignition the bike will run just fine if the ground wire is broken but in some cases it will shorten the life of the control module because of EMF and flyback. Jim

There is an electrical requirement for the engine itself to be grounded back to the battery for the return path of spark plug current. You don't want a secondary spark occurring across iso mounts or whatever. Points ignitions also need a good ground, as does a TriSpark module. The factory connected everything to a pigtail and lug that attached to the head steady. Some folks rout it right to the head, some to the frame and then to the head with copper braid. Your choice.

Stick with the advice above and you'll be mare than fine, braided straps are fine for postions where they will not come into contact with weather etc, if used outdoors they can be raychem sleeved, but as I have found on numerous ships the slightest bit of moisture and they rot inside the sleeving.

Yesterday I fitted an earth/ground strap form the head steady to the head, I also upgraded the coils to the Tri spark coils as I run Tri spark ignition. I noticed improved starting and much, much better idle although with the ice on the roads I have not managed a proper test ride (Call me fair weather). I couldn't tell you if it was one or both the changes that made the difference but I am glad I read the above threads. Thanks