Tach Repair

[pearsonbe]

I am planning to repair my tach and I can't see the colors on the burned resistor. I found this on the wiki:

http://fzronline.com/wiki/doku.php?id=tacho_electronics

The second image shows the resistor that is blown on my tach. It is labeled R7 and appears below the two black capacitors. I think the color bands are: blue, gray, brown, and gold. Will someone confirm this? I don't want to replace a part with the wrong OHM value.

Now that I'm looking at it, R5 looks suspect on my tach as well. I'll check Radio Shack.

[Fizzinatorr]

I would suggest get some second hand gauges should be easier to just swap

[pearsonbe]

That would be easier, but not less expensive. I've dropped a few hundred dollars on the bike over the past couple of months. And at this point, I have more time than money. Resistors are cheap. If the first try doesn't work, I'll replace the cluster.

[pearsonbe]

Pulled the bad resistor from the unit and took it, the tach, and the image with the color bands to the 'Shack hoping they could help me sort this out. They were informative, but could not determine the right OHMs either. Mine is too badly burned. Based on the image, we decided to go with 680. However, I still don't have the wattage. Judging by the size alone, it looks like a 1/4. They didn't have what I needed, but the manager is a tech and offered to give me one from his kit at home, if he has it. Cool guy. BTW, he agreed it was worth saving.

[pearsonbe]

Replaced the resistor yesterday, but haven't tested the tach in the bike yet. It may have to wait until this weekend. Is there a way to bench-test it?

[Fizzinatorr]

So? Did it work out for ya?

[pearsonbe]

Hey. Still haven't tried it. I may have a bad VR and didn't want to risk ruining the tach. When I started the bike Saturday, I noticed smoke coming from a 30 (amp?) fuse near the VR. So I shut the bike off and could hear gurgling/sizzling sounds coming from the battery. When I touched the fuse wiring it was hot. I have also had battery charging issues.

The next step is to upgrade the VR and check the battery. I hope it's not bad, it was new. When that's done, I'll try the tach.

[DonTZ125]

Holy crap - boiling battery bad! You most certainly have a bad VRR, and you're about to kill the TCI as well. Park it until you get a new VRR.

*ahem* (vulture mode) VRR Adaptor Harness *ahem*

[pearsonbe]

Yup. TCI? Is that another name for the computer? I had to replace the ECU to get the bike to start. That's probably what killed the original one.

[DonTZ125]

"Transistor-Controlled Ignition", as opposed to "Capacitor-Discharge Ignition"; the processor-controlled black box that makes the sparks fly, and a frequent also-died when a VRR lets go.

[pearsonbe]

Ok. I noticed you have helpful info links in your signature and that you repair TCI units and sell a R6 VRR harness adapter. I'd like to talk to you about it and will send an email.

[DonTZ125]

I was just contacted off-line by one of our temperamental-yet-electronically-experienced readers, and he points to this post in an older thread as confirmation that the part in question is a 680 Ohm 1/4W resistor. He also made the very valid suggestion that pearsonbe could unplug his VRR and - assuming the battery had sufficient charge - safely start the bike and test the tach.

Y-G - would you be able to update the Wiki for this topic, confirming the R680 value of R7? I am Wikily challenged ...

[pearsonbe]

Nice! I will try that this weekend. I did search the forum before I originally posted asking about the resistor. But I didn't find that thread. How long will the bike run without the VRR? Maybe until the battery voltage drops too low to support a spark. It shouldn't take long to check the tach.

Did you get my email yesterday?

[DonTZ125]

Racers running total loss generally get around 2 hours out of a good, freshly charged battery. Bear in mind, yours may be damaged internally from the over charging. Pull your headlight fuse to remove that load from the system.

I replied to your email yesterday ... ?

[pearsonbe]

I wanted to test the tach yesterday, but the battery had other plans. The shop tested it and it's bad. I bought it four months ago, so the must have VRR killed it. Ordered a new one. The new R6 VRR and wiring adapter are here. The adapter looks like quality - thanks Don. Did I read somewhere that you can use a car battery with a bike?