slabside 1100 oil light on

[Trapjaw]

Hi all. Trapjaw from South Africa here. I just bought a (mostly) mint, low mileage 1986 GSXR 1100 G in standard blue and white trim. Everything on the bike is original and unmodded, engine is super clean with no rust, leaks, drips or anything. Bodywork is all original, absolutely spotless. Real gem. Previous owner had it garaged for a long time, and said it hadn't been ridden in months, but assured me she was running like a peach. When I checked it out we started it up, and it fired up and idled decently, but sounded a little noisier than the bikes I'm used to (more modern water-cooled bikes). I put down a deposit to secure the purchase, then was out of the country for a month, and when I returned last week I went to pick it up.

It started okay and I rode it home, but it seemed like it was running a bit rough - would cut out when I stopped and wouldn't idle.  I put this down to a flat battery, as it had been standing unused so long. Checked battery voltage - it was low, as I thought. Charged it, put it back in the bike, she fired up quickly and idled no problem. Multimeter readings seemed okay for the charging system. 15 volts while throttle held at at 3000rpm and when revving higher. That was 2 days ago. Did not ride her again until today. So, took her out this morning to run down to the DMV to sort out the paperwork. Less than a kilometre after leaving my house, suddenly starts feeling rough and the oil light comes on. I pull over and kill the motor. No oil leaks, oil level in sight glass is fine. Start her up, oil is bubbling in sight glass, so oil is moving around the engine, presumably, but oil light is staying on while it is running. Kill the motor. Try start again, but now it's reluctant to start. 

I don't want to ride it anyway, so a push back home it is. Take out the battery and check it, and sure enough the battery is low. Alright, so, old shitty battery, that's the issue, right? I went and got a new battery, started her up - fired up and idled and sounds relatively smooth, but now the damn oil light is sticking on. 

I'm pretty worried now. Any ideas what might be wrong? 

[colinworth79]

with the old oil cooled engines they are a bit noisy but tuff old things . To me 15v is a bit high , my gsxr 750 L had a running fault that i finally traced to over charging and boiling the battery . It is going to be either a bad connection or a poorly regulator unit in the alternator . The oil light problem is possibly a faulty switch located under the small engine cover on the right hand side . Remove cover and take wire off the end of the switch and touch the wire to the engine case . The light should go out . If the above checks out ok I would remove the switch and fit a pressure gauge in the hole and check . Should have a fair bit of pressure just by spinning the engine over on the starter . If pressure there its a faulty switch . If there is no pressure then going to have to take the sump off . Has been know for clutch friction plates to fall to bits on something that's been standing for years and block the pick up .

[Trapjaw]

Thanks for the reply Colin. I'll pull that cover off and check the switch. Hopefully that's the problem. 

I think, as you said, the regulator is probably not working 100%. I've had problems with regulator rectifier units in the past. 15 volts did seem a little high, it was even going up a little past 15 volts. I'm thinking this is what killed the previous battery. Googling "gsxr 1100 G regulator" doesn't come up with too much, and it doesn't seem to have an external, sealed reg/rec unit (black, finned, plug in) like most bikes I've had. From what I can see the early GSXR's regulators are IN the alternator, so I'd have to take that apart to replace it?

[Gixer1460]

Yep - all integral, but not a difficult job.

[Captain Chaos]

before taking it apart, check this out:

http://oldskoolsuzuki.info/archives/400

[Trapjaw]

Thanks guys. And thanks Captain Chaos, that looks very helpful and seems like something I should try before getting a new regulator. 

I might sound like a complete idiot but in that article, what type of relay is Katanamangler talking about? My knowledge of electrical terms is limited to the basics... I can see that it's a DC12V 30A (right?). Is this something I would get from an electronics store or is it motorcycle specific? and the numbers within the diagram (85, 86, 87 and 30), what do they refer to? 

[Captain Chaos]

any car parts store can sell you the relay, it's just a basic one.

In automotive electronics technology every connection has its standardised code. These numbers are writen on the relay itself.

 

Edited November 9, 2017 by Captain Chaos

[Trapjaw]

Thank you! You guys are very helpful. Will keep you all updated about progress.

[Captain Chaos]

You're welcome.

Now post some pics of your mint Slabby. We like pics.

[Trapjaw]

On 11/8/2017 at 10:54 PM, colinworth79 said:

 The oil light problem is possibly a faulty switch located under the small engine cover on the right hand side . Remove cover and take wire off the end of the switch and touch the wire to the engine case . The light should go out . 

Alright, I've finally had the chance to look at my bike. Took off the cover, did this and the light goes OFF when I remove the wire and ON when I touch it to the engine case. Bad switch? 

[Gixer1460]

Yep!