Believe it or not!

[MPittma100]

Having read several posts about fried connectors, misfiring cylinders in the rain, etc., brings something to mind that I had an experience with in the past that can and probably does relate to these problems.

Our bikes, correct me if I am wrong, have the battery ground cable attached to the frame. Well, believe it or not, this is a POOR ground for most all of the electrics (including the spark plugs) on the entire bike.

An elctrical engineer/manufacturer acquaintance of mine and I went round and round a few years ago about battery ground.

He and is associates preformed a test with different metals to see which ones (if any) would equal the conductivity of a number 4 (0) gage copper wire. You may not believe it, but it took a piece of steel 1 and 1/2 inches in diameter and 18" inches long to equal the copper. I did not believe it either and told him so.

I was having a problem with an electric water pump (that he sold) with a rubber impeller that was continually melting the impeller.

His first question to me was "how is the pump grounded"? I said to the chassis. He said ground it directly to the battery and your problem will be solved? My brain was telling me that this guy is nuts. I asked him to explain and he obliged.

He first said look under the hood at any automobile or truck produced and you will see that the battery ground cable goes directly to the engine. All else except a few light bulbs ground from this point. He added that anything of significance i.e., electric pumps, motors, compressors, etc. grounded to the chassis rather to the battery will draw EXACTLY TWICE the number of amps that they were intended to. And furthermore, the spark plugs will fire with full energy as compared to a chassis ground.

In my case the water pump was drawing 14 amps instead of 7, overheating the armature, to which the melting impeller was attached, causing this failure. Guess what, I still didn't believe him. So I did it his way and................YES the problem was solved! YES I am a now a believer!

I have made it a point since to provide this proper ground to many, many applications which have equaled much impproved performance. Failures of this type for myself and others that I have changed disappeared.

Think about this. How is an engine grounded through rubber engine mounts without a ground cable going to it?

In conlusion, I believe that we could prevent many electrical failures, improve performance even further, and chase fewer ghosts, not to mention better battery charging, by simply improving the ground over the factory setup. I am going to do it to mine ASAP.

Thanks for listening and not falling asleep too many times.

MP

[DGXSER]

Interesting point. Of Course, the engine is grounded to the frame as well, and very close to the frame to battery connection. However, I am certain you are correct that a direct ground would be a better choice. The issue of course being a path to get there.

Honestly though, what you will find typically is that the melted terminals are from XSive corrosion in the connections. And the wet mis fire is typically cracked coils, or bad plug wires or connectors.

My bike has always been very tough to start after a good washing at the drive up auto wash joint. Typically had to let it sit for a good ten to fifteen minutes. Then I got caught out on a VERY rainy day with the bike. I thought sure I would be sitting on the side of the road. however, I drove it through mild rain to heavy down pour for 30-40 minutes and it never missed a beat. Same thing on the way to XS East, hit heavy rain for 30-40 minutes. Never missed at all. I did recently replace the coils as I found one had a crack in it.

[soccer4m]

How are you going to do it??

Hey MP,,,you are right on with the grounds on these bikes. I had a wierd issue starting my bike, sometimes turning over sometimes not, as with running. If I tilted the bike it ran better, but still intermittant, TUrns out it was a cracked ground connector at the frame, hard to see until I took it out. Repaired it and voila, no more wierd issues.

Question, how are you going to improve the grounding??? I am guessing copper wire from the engine to frame, to battery,,,,,,let us know...Mike in Sun DIego

[crazy steve]

Well, it's not quite as bad as you say, but depending on a ground through the steel frame/body can leave a lot to be desired. Steel is a notably poorer conductor, but not so poor as to double the amount of current used by a circuit except in certain cases (very long current paths). It's been common for years in the vehicle industry to use the steel chassis/body as the 'ground return' path for nearly all circuits. The quality of your ground connection can be harder to make with steel or iron, as it rusts faster than copper or brass corrodes in most cases. As a vehicle ages, the electrical 'fit' between steel parts can degrade, leading to dim lights and smoked parts.

But with that said, I'll agree that the ground system on these bikes leaves something to be desired. I'm now 'bonding' the three ground points together on my rebuild projects by running a #12 wire between the ground connections. On my '78 'modder' project, I actually welded on a new frame 'ground tab' above/forward of the battery to take the negative cable to and will connect the harness ground directly to that, eliminating the path through the frame.

Yamaha is a little better than most in that they actually ran a harness ground wire to most devices on the XS/XJ bikes. They didn't size it big enough IMO, but they tried...

[MPittma100]

Will Do

Mike, I will contemplate a plan on the best way to do this. Will study the bikes and get a procedure in place likely after some trial and error. And will post as soon as I have a good fit.

MP

[MPittma100]

Good Idea

Steve, I agree. Not terribly wrong, but can be made better and does need to be made better. We all know that certain things get compromised in mass production/assembly processes. Unfortunately, the electrical system is one of them.

MP

[strom]

When I was first assembling my 78E, I didnt have a clue how things should be put together. i sorta dug a part out of the box and put it somewhere, where it looked right.

Anyway, I was at the stage of cranking the motor by using the starter. It was turning slow and my clutch cable began to melt.

It was the only ground from the chassis to the rubber-mounted engine.

It was an easy fix, but I check these things nowdays.

[TADracer]

I am certainly a bit challenged when it comes to circuitry however something I did a few years ago similar to this I believe had a very good result.

When I did a frame off renovation of my machine in 2008 I added a ground strap from one of the starter bolts directly to the point on the frame where the battery negative wire bolts on. So in effect, it is a direct to battery ground. This is in addition to the OEM ground strap which I left in place. Other than this, all I did electrically was to clean the connectors on the wiring harness and put it all back together. Now it might just be my imagination but since then I have had absolutely no electrical problems other than the reserve lighting unit failing.

[MPittma100]

Proof Is In The Puddin'

I got around to improving the battery grounds versus the chassis grounds today. Found something that absolutely prooved that the chassis grounds are, in fact, inadequate.

Started out by making a couple of ground straps out of 10 gage copper wire. Put the round hole crimp-on terminals on each end.

The factory grounds are: battery to frame and engine to frame (at two different points). I took one wire and connected between each (both) chassis ground fasteners. So there is now a continuous ground loop directly from the battery. I added a second ground wire to the first chassis ground point from the battery and ran it up and over towards the tail light harness connector under the seat.

I was having an issue with two aftermarket tail lights added by the PO. They were being used as additional brake lights.

The issue: If the running lights were on (key on), and you depressed either brake, one of the aftermarket lights would burn very dim? Also, if you turned on either the t/sigs or emergency flashers with the brake lights on, the one (same) light would flash on and off?. Note that the two additional lights are a) on a relay and b) are LED bulbs. Bottom line is that the two extra lights would not come on together as they were supposed to. These lights, as well as the stock tail light(s) are all grounded through the tail light harness.

I attached the end of the second (battery) ground wire to the ground wire in the tail light harness at the connector under the seat. Guess what? Light problem disappeared! Now, when depressing brake, with t/sigs or emerengency flashers on, the brakes lights are steady and bright.

There may be one other point to continue with a battery ground. That point is where the regulator/ rectifier is currently chassis grounded. I have yet to do that. I hope that I have explained to where you can understand the procedure. I have included some pix that may help. The fact is that the chassis grounds are inadequate as suspected.

MP

[MaximPhil]

Hi MP,
Thanks for sharing that. i will add that to my list of things to do.
My question is:
What the hell are you doing with TWO drums of Racing Gas
Phil

[IanDMacDonald]

When I had my Yammie down for the Summer last year, I bought a cheap Suzuki GS that obviously has a history of electrical gremlins. Anywho . . . smart cookies on that forum, and they believe in ditching all of the numerous frame grounds, and follow a "single ground" to the battery. It basically eliminates the quality of connection issue, and rules out grounding issues. I actually did pull the wiring harness apart when I rebuilt it with larger gauge wire, and was surprised to find a lot of my issues disappeared. To really understand these bikes, you have to understand the other XS bikes, as they all are similar in one way or another. The Triples site that I belong to is great, as the 750 and the 1100 are almost duplicate bikes with an extra cylinder slapped on. I'd say the grounds are not so much a problem as corroded terminals and the old fuse-type box. Converting to a mini-blade panel is definitely worth the investment.

[MPittma100]

Racing Gas?

Hi Phil,

Those drums are actually racing methanol (alcohol). My SWMBO and I are (car) drag racers. She is the 2012 Track Champion in Super Pro at our track. I am proud of her.

We run the alcohol fuel in two cars. One car is a small block Chevy making 655 HP. The other is a big block Chevy making around 800 HP. We race about 20 races per season which is from March through October. Will finish up the season on the 28th of this month.

MP

[MaximPhil]

Hi Phil,

Those drums are actually racing methanol (alcohol). My SWMBO and I are (car) drag racers. She is the 2012 Track Champion in Super Pro at our track. I am proud of her.

We run the alcohol fuel in two cars. One car is a small block Chevy making 655 HP. The other is a big block Chevy making around 800 HP. We race about 20 races per season which is from March through October. Will finish up the season on the 28th of this month.

MP

Hi MP,
I thought there might be a story there
I hope you are both having a good season.
Racing Chicks Rule
Phil

[Yard Dogg]

In my opinion, the plastic OEM spark plug boots, even the NGK ones are not very good. Even though they have rubber boots, it is still a small sealing surface. Also, the plastic pug boots are designed to fit on the threaded spark plugs. I like to use regular automotive spark plug boots such as MSD for their larger sealing surface to the plug and wire, also they have a larger contact surface to the plug because they use the larger round type spark plug contact. I agree that battery grounding is definitely better than to the frame alone because it would be less maintenance anyway. Frame grounds rust quicker.

[spayne83]

Back from the Dead

I am wondering if you can just have the one battery ground to the engine and then run all the frame grounds to the battery terminal? Is there a need for a battery - frame ground and an engine - battery ground?