Will not start GS550T (1981)

[lecroy]

I am sorry. Normally my brain is not so out in the weeds. I went back and read what you had wrote. Yes, you are on the right path. Yes, get a cheap Volt Ohm Meter at the local hardware store. Don't spend more than $30 on one. I have not seen a regulator go bad on any of my Jap bikes, but have seen problems with the stator on one and connectors failing on others. If you find a good flow chart, no problem. If you need help using the meter or have questions on the chart, I will try to be more on the ball next time.

[argonsagas]

Do the checks as recommended.....only one qualification..Lecroy suggested using a cheap VOM...my experience has been that the cheap ones give inaccurate readings, but this is not necessarily a constant as it may have been because the ones I tried came from the same store..

First thing I would look at is a bad ground. The hint is that a battery from another vehicle will work right away....reason is likely that the car battery has a higher voltage potential than yours and (since it is bigger) has a deeper draw, while yours has suffered due to a bad ground, even though it was on a running bike, plus the bike frame etc. may have heated up a bit and, coupled with rust/corrosion, the heat may have worsened an already poor ground..

Wire the battery ground terminal directly to the frame AND to the starter .
Make a new and clean connection to be sure.

Clean all other connections on the bike as well....all of it is for your benefit.