How do you check a signal generator?

[hikermikem]

I have an "85 GS550L that I'm trouble shooting - I've replaced a bad coil & I'm trying to check the sig generator as well.

Any idea how to do this??

thanks,

mike

[LeeGS550E]

Throw it in a bucket of water. If it floats, it's broken.




JUST KIDDING. DON'T DO THAT!

You are going to need to learn to search the forum first. Their are lots of posts on this, and even if some of them don't lead to a direct answer, they will help you lots with learning about our bike's systems.

Next, you will need to download the factory service manual from www.repairmanualclub.com. Its kind of a tough site to work with, but you are going to need this manual over and over again. It is the best manual available...better than haynes or clymer. It will give you specific ohm ratings for each of the circuits in the ignitor. Get the manual, it will save your life.

[hikermikem]

You are a funny guy Lee.

Yes, my searching could be better. The manual for my 1985 GS550L is not at repairmanual.com. I've already downloaded the 1983 they offer, but I've noticed some differences between the two years.

i was hoping someone out there had some experience with an '85.

Thanks for the response.

[LeeGS550E]

The coils should be somewhere in the range of 3 ohms. Mine read 3.4.

As far as the ignitor units, check to make sure you are looking at the correct part. They are listed as the same part # on bikebandit, and I don't see why they would have changed. You may be looking at something wrong in the manual or the wrong part on the bike.

Its that, or, someone plugged a toaster in there instead of an ignitor unit.

Like I said when you asked this question before, the part # is the same for the '83-'86 years. I think your getting mixed up on your parts. The factory manual that you have works the same for the '83 e, es, and l models, as well as the '84 and '85 models. The way I know this is by checking bikebandit.com and flatoutmotorcycles.com for the ignitor on both the '83 and '85 models. Check that part for both years, and you will see the part # is the same. So you should be able to test the '85 ignitor with the same procedure and specs as the '83. Sorry to keep hitting you with this, but that's just how it is.

[DickV]

Signal generator check

Here is how I checked my signal generator. I used my digital voltmeter, set to a low AC volt range of about 3 volts as I recall, and hooked the leads to the connector coming from the signal generator (SG) which goes to the ignitor. Polarity is not important, it's an AC signal. If the SG is working you should get voltage readings on that connector as you crank the engine. The SG generates a low AC voltage each time the magnet goes past a winding and it does this for each cylinder. This voltage then triggers the ignitor to switch one side of an ignition coil primary to ground. The absolute values are not important, just check to see that in fact the SG is producing voltage spikes for each coil.
DickV

[nabrams]

DickV gave a very good description of how they work and how to test them.
Now, if they don't pass his test, the next thing to do is to find a signal generator on eBay for real cheap - I got one for my friend's bike for like $4 (including shipping - they are very light) - for that price, it's worth a try.