550 got some loving today!

[Lifttech81]

I can post the vin number if someone who knows more wants to look? Or is that frowned upon

[Lifttech81]

Vin starts with js1... do I have a Japanese spec gs? Or am I getting excited for nothing

[Rich82GS750TZ]

If you think it's important. If you have a working on/off switch, good for you. Just remember it's not legal drive a motorcycle on the road with the headlight off (I'm pretty sure this is true in all 50 states and Canada). I'd clean all the contacts in that housing and put it back together, charge up your new battery, then post up new quick test numbers, all 6 of them. The test is linked in my signature, but this is what you should be seeing.

Quick Test Steps:

1.) key off................Normal 12.7 volts-12.9 volts

2.) key on (but not cranking with lights for 10 sec).....Normal 12.2-12.5 volts

3.) at idle (1500 rpm).....12.6volts - 13.2volts

4.) at 2500 rpm 13.5 -14.0 volts

5.) at 5000 rpm.....14.0 -15.0 volts

6.) key off.....slightly higher than measurements # 1 (12.8-13.0 v)

[rphillips]

1978 U.S. passed a law, all motorcycles on public roads had to have headlight on. The "78" & newer bikes couldn't have a working switch to turn the headlight off. Suzuki used the same left hand switch, for the "78", & maybe later, model bikes as the "77" models, they just installed a little plastic "stop" to keep the headlight switch from being slid to the off pos. The little "stop" could easily be trimmed off with a pocket knife, to make the switch usable again. Can't tell from that parts diagram, but kind'f looks like the "81" 550T was still using that same LH switch. Congrats, I wish all my bikes had a headlight switch, for the exact reason you've found. Mfg's did different things, I think Honda, when the start button was pushed, the headlight went off, & Yamah, the headlight didn't come on till eng. started. Suzuki took the worst option.

[Lifttech81]

I dont believe it's important I've just always been a fan of japanese spec cars and bikes. On my way to the shop for a new battery and I'll be doing some cleaning here shortly. Will repeat testing from the morning and post results.

[rphillips]

Could you post a picture of your LH switch. Not important, but would be interesting to see if it looks like the earlier GS switch. The 550T may have been using up some earlier left-over GS parts. Have I forgot or am I correct in remembering the "T" models were the most economical model of the GS's? I see now I've forgot some stuff, I's thinking the "T"'s had spoke wheels & rear drum brake, now not sure what is was, but I think the "T"'s were the cheaper model of the GS's.

[Lifttech81]

T is touring model, no kick start upgraded generator. Spoke wheels and disc brakes front and rear

[Lifttech81]

[rphillips]

Almost sure, that on/off knob should have a small piece of plastic, that goes down in the slot, that keeps it from being slid to the off pos., maybe the same switch used in other countries, but they had a knob without the plastic stop, so it could be slid to the off pos. Newer style had just one button, slide button up/down for hi/lo beam, & slide same button R/L for R turn & L turn. Thanks for the pic. Glad you found what was wrong.

[Lifttech81]

Huh interesting. So I got the new battery in and all connections checked and cleaned. new values for voltage test below

Key off engine off 12.3
Key on engine off. 12.1
Key on cranking. 11.6
Key on cranking with headlights. 11.4
Key on engine on. 12.2 to 12.8

Started everytime after new battery install. Think I got it squared away for now!

[Rich82GS750TZ]

You didn’t post all the quick test numbers. No telling fs battery is being charged or how well. Post all the numbers.

[Lifttech81]

2500 rpm is 13.3 to 13.8
5000 rpm is 14.2 to 14.6
Battery is staying at 12.6 after running, engine off

[Rich82GS750TZ]

I’m no expert but those numbers look good for the state of our charging system. If you’re no longer experience the occasional no-start issue, maybe you cleaned the right connector. Who knows.

[Lifttech81]

Yea the old battery had no date. When I put it on the bench tester it failed immediately. All connections looked okay and were tight. Seems to be charging well now and holding a charge after a long ride.

[cowboyup3371]

I can turn my headlight off/on on my 81 550t as well - they made two different kinds of mechanisms for that year.