Topic: Kuryakin battery gauge review, and why I'm glad I got it!

[AndreRA3]

So, onto round 2 of André's incredibly insightfull, although unsolicited, product reviews:

I installed a Kuryakin battery gauge on my 74/78  Cb750k  today, and was at first a little concerned.

You see, my battery was measuring at 12v exact, while the Kuryakin gauge swore I had only 8v.  Weird.

 At first I thought it was the connections, so I checked everything and all was fine.  I installed the gauge on my handlebars (via the provided double sided tape, but I'll J-B weld it later), and connected the wires to a spare ground and to the gauge lighting wires (both inside the headlight case) by using bullet connectors I bought at Radioshack.  I thought the connections were bad, but as I checked the same wires with my digital multimeter, the measurement agreed with the gauge.

So now I'm weirded out and worried, since I know that those wires are 12v (or whatever the electrical system is putting out).  All this is with the bike running, by the way, and reving it up does absolutely nothing.  Confused, I have the first brilliant idea of the day, which is take out the headlight before I drop it and brake it.  Amazingly, the minute I take out the headlight, the voltage jumps to 13.5 at idle.

ok...  so my headlight is taking up too much juice... but it shouldn't be... it's a 55/60 watt halogen bulb.   I replace it with the dimmer 55/65 watt sealed assembly I had before and BAAM!!!  8v again.  but it jumps to 13.5 when I rev it up.

Huh?

I replace it with the old headlight.  8v again.  14.5 when I rev it up.  12v at idle

WHAT THE %@##???  How??  When??? Why???


In chimes my father, who tells me it's probably a short somewhere (he was freaked out by the rat's nest inside the headlight bucket.  He calls it a rat's nest, I call it my wiring harness).  So we start isolating every connection that could possibly short out (there were a few) with electrical tape and putty.  We turn the bike back on and it says 13.5v at idle.  14.5v revved up. 

Oh Yeah!


Needless to say, we left it at that and reassembled the headlight.  After reassembly all remained well, so hopefully it will stay well.  I still think it's weird that the actual system voltaqe does not match voltage measured at the battery, and for that alone I'm glad I installed the battery gauge.  Maybe its because my battery isnt fully charged, since the bike was shorting out somewhere, but I'm glad I know that now, and thought you guys would like to know.

Anyway, I hope this helps someone...

BTW, I bought the battery gauge on ebay, but I'm sure you can get it at bike stores and such.

André

[AndreRA3]

Oh, yeah, I was going to do a short review of the gauge, wasn't I? 

I personally like it.  It's very small, lightweight, easy to install, etc...  I glued mine on the clubman style handlebars I have, and it's barely any wider than the bars themselves.  The leds are very bright, though and easy to read.

I know how well it performs tomorrow when I ride to college, but I see know reason why it wouldn't be as good as tonight in my garage (other than the double sided tape coming off.  If that happens, I'll jb weld the thing down and let you guys know.

That's all I can think of for now....

André

[Dennis]

My guess is that there was no short.
I would think that there may have been some corrosion, oxidation or just poor contact in one of those old connectors that you moved around and that when you handled it there was a better electrical contact.
I would suggest that you might want to take each connection apart, inspect and gently clean and reassemble with dielectric grease.
Just my opinion.

[oldbiker]

There is no possible doubt, a poor connection is the problem. Obeying the laws of electricity, when there is a resistance with current flowing through it the voltage measured at the two ends of that resistance will be different. In other words since your connection for the guage is taken from the headlight feed wire or is earthed at the headlight earth wire, when you switch on your light the current drawn causes a voltage drop across the high resistance. This shows on your guage.

[MRieck]

I agree with the 2 previous posts. That gauge is pretty good looking and the cost reasonable.

[AndreRA3]

Thanks, guys

I'll look into the connections, but let me clarify where I connected the battery gauge:

The positive end was connected to the same positive feed as the speedometer and tachometer positives (for their light).
The negative end was connected to a unused ground connector inside the headlight bucket (where a lot of connections for my wiring harness are tucked away).
To the best of my knowledge, the wires I linked the gauge to have no direct relationship with the headlight.
The voltage read by the gauge is the same read by a multimeter in every positive connection inside the headlight bucket (that I measured, anyway).

If the problem comes back, I'll clean more connections and apply dilectric grease to them (this was already done with all the connections I "short-proofed" last night).

My problem now is figuring out if I have gasoline in my oil.  I left my petcock open last night, and a few minutes ago my bike stank of gasoline.  I took one of my pods out of the carb and some gasoline drained out.  My tank is very low, too...  yeah, I think I'll have to change my oil again (last oil change was last weekend, not even 7 days ago).

bummer.

André

[AndreRA3]

Just a follow up:

I checked the oil and saw/smelled no gas in it (after running the engine for a few seconds), so I rode the bike to college and back. 

The battery gauge worked flawlessly, and the voltage was perfect at all times (bordering low on idle, but that's normal).  It was extremely windy today (riding tilted to go straight, etc), and the gauge kept very still on my handlebars, so that looks good.

I filled my gas tank on the way to school, and got 2 gallons for 65 miles.  A bit low, but not bad, so not that much gas drained down the carbs.  Upon returning home I checked the oil, and the tank was FULL of oi & gas, and the oil acted a bit watery (it's 20w50 Royal Purple) and was colored a bit light (the oil actually is dark purple when new).  So I did have some gas in the oil, but as it was a little overfilled with oil, at 1 gallon exact, not that much gas must have gotten in...  No biggie, tomorrow I'll change it and the filter, and the 15-20 miles I rode today probably didn't do too much damage (rpms were kept low, oil was brand spanking new, the engine god grows increasingly fond of me, etc).  Hopefully everything is fine, anyway.

Hope someone else benefited from all this, and thanks to all who helped out.

André

[AndreRA3]

Another follow up on the battery gauge:

I just glued the gauge to my hande bars with JB weld.  The double sided tape was good and sticky, but I wanted to have a pretty steep angle on my gauge, since I have clubman type bars...

Otherwise, the gauge works perfectly.  Gets very bright during the day time, and dims down at night.  Never hard to see, never too bright.

Cool 

André