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I'm back! Need help! Again...GT80

Posted: Fri May 28, 2010 9:51 pm
by jbswear
Okay, so my GT380 has been sitting for many moons now...You know the old story...Life gets in the way.

Anyway, I'd like to have the bike at least running in the next month or so.

Here's the back story for those of you who don't remember:

Bought the bike, in sorry shape, but complete two and a half years ago.

Spent three hours or so cleaning 29 year old gas out of the carbs.

Kicked it over a bunch of times with the key off, turned the key on, and it started on the first kick.

Thought I'd try to ride it. Clicked it into first gear and the chain snapped. Since then, I haven't done much to it.

A year ago I tried working on it again, but had no spark at the points. Messed with them (like a fool). Couldn't figure it out. Bike then sat for another year.

Started working on it again recently, and figured out the key switch was bad. Replaced that and now I have lights. No turn sigs, but I'll get to that later.

I do have a fat, healthy spark at the L breaker every time it opens, but nothing on C and R.

I have forgotten the procedure for setting points. One of the nice guys here walked me through it by phone, but it's been forever. My service manual doesn't tell me the procedure.

Can you guys help me? Again?

Posted: Sat May 29, 2010 10:58 am
by jbswear
A bit of information that might help. I think I'm seeing something wrong, but don't know how to use the info...

I used a multimeter across the points gaps both open and closed. Here's what I came up with. Mind you, the battery is iffy, at best, so I had it hooked up to a charger to keep the power up.

Key off--no voltage across any of them, open or closed. Good.

Key on--

00.0 volts across the L breaker when closed; 11.3 volts when open.
11.4 volts across the R breaker when closed; 9.8 volts when open.
11.4 volts across the C breaker when closed; 9.6 volts when open.


So...I'm assuming I should read ZERO volts across all three when closed, correct? If so, How do I get there?

Posted: Sat May 29, 2010 12:23 pm
by jbswear
Figured it out...points were corroded, so they had too much resistance.

I have spark again!

If you never hear from me again, it's because, against my better judgment, I tried riding this derelict and died in a blaze of glory!

Posted: Sat May 29, 2010 1:56 pm
by Joiseygirl
Perseverance wins again!

Good for you! :)

Posted: Sun May 30, 2010 10:17 am
by Buffalo-guy
JB
The thing about points is, they are trigger mechanisms, not load carriers. If you are still seeing spark across the points, then the condenser is failing, and your points will continue to erode and malfunction. Don't forget to put a drop of oil on the cotton swab, for lubing the cam surface. Your rubbing blocks will wear, and the timing will change with it, if you don't. Points work just fine, given a little care and attention. Sounds like you're learning. Cheers.
Fred

Posted: Sun May 30, 2010 3:24 pm
by jbswear
So I should or SHOULD NOT see a spark across the points when they open?

I'm confused. I thought that I would see a little spark each time they open.

I'm contemplating an electronic ignition, but don't know who carries them or how much it will cost.

Posted: Sun May 30, 2010 5:22 pm
by Coyote
The 'spark' at the points is very minute and generally only visible in dark or near dark conditions. If you are getting a strong easily visible spark at the points, the corresponding condensor is toast.

Posted: Sun May 30, 2010 5:39 pm
by jbswear
Coyote wrote:The 'spark' at the points is very minute and generally only visible in dark or near dark conditions. If you are getting a strong easily visible spark at the points, the corresponding condensor is toast.
Well, maybe strong isn't the word for it. It's hard to see in bright light, but I can sometimes hear it if I'm careful.

In other news...I rode it! First time it's been ridden since '79. Weird feeling; I've never owned a 2-smoker.

The right cylinders were firing, but the left wasn't. I pulled off the carbs and found this junk:

Image

Image


So I cleaned it out, but found the idle jet (the small one, right?) frozen inside the carb body. It stripped when I tried to remove it, so I'll scour eBay for a replacement.

I put it back together, kicked over a bajillion times, and got it running. Against my better judgement I figured I'd ride it down the street. Yeah, it goes! But the left side started bogging; the right and center exhaust are hot like expected, but the left isn't.

But I don't care! I'm happy!