1983 Suzuki GS 1100 ESD Tach

[reddirtrider]

why is that?

Just from reviewing the wattage chosen for the wirewound resistor. It's right at the edge when assuming that the input voltage is 12v, and we all know that it can rise much higher than that.

I'm leaning toward a 10 or 12v reference now. I've been wrong before, and this is just another guess as I have no idea what's in that IC. If we knew that, it wouldn't be hard to figure this out.

I'll get an assortment of zeners and see what happens. My 47 ohm was open and the zener is bad, I'm hoping that's all that went south. I didn't see any shorted caps.

On the positive side, the rest of the bike is coming together and I'll be looking at painting it in another week or two (at the most).

[posplayr]

Nicholas

Nicholas,
Do you have access to a tach like one built into a timing light? This would give an idea of how far off you are.
Looks like your are not off by more than 50%.

Red,
If everything else is OK, then 5.1V is probably not the right voltage. Unfortunately there is no way to know that?

Nicholas, did you change any of the caps?

Jim

GOOD NEWS!!!

I replaced the original zener diode with a 5.1V 5 Watt zener diode. I now have response from the needle.

Here is a video of what is happening.

It seems like the needle responds slowly, and that it registers less than the actual RPM.

My theory:

The diode is really a ~12? V diode, the 5 V diode supplies about half the voltage to the needle, so it has about half the current, and reads half the rpm.

Looking at the video again it looks like it is closer to the actual RPM than I originally thought. Could someone who has one of these bikes please tell me what speed you're traveling in 2nd gear at 6000 RPM? I'll take mine out and see if it is close. Thanks

Let me know what you think.

http://s464.photobucket.com/albums/r...ent=tach-1.flv