gt185 ec rebuild

[stinkwheel]

Firstly, Good Evening from a chilly England ! I've recently bought a "barn find" gt 185 ec (last model with cast wheels), and, whilst constructing my new man cave, I've started pulling the bike apart. Well, not exactly apart, but more like cleanling stuff, so that when I get near the bloody thing I don't end up covered in crud! Anyway, feeling optimistic, I thought I'd try to get the thing running before completely dismantling it; a. just to hear it and b. give me some belief in the project.

So, as it stands,I haven't heard it and my belief has had its first wobble. Basically, using the kickstart, I've got a spark on the rhs cylinder but nothing on the left; I've swapped over/renewed points and /or condensers/ plugs and it would appear that the issue is on the lhs. I tested the ignition coils and both primary and secondary coils tested the same for resistance on each coil ( approx. 4.2 ohms on the primary and 8.7k ohms on the secondary). Assuming that by testing the same thay are ok, does anyone have a thought on my missing lhs spark??

Many thanks for any suggestions.

[Alan H]

Check that the points are wired correctly and aren't permanently earthing due to a misplaced washer, also that the condenser on the dud side is OK.
Where are you in the UK?
I'll be working on an early GT185 on Friday.

[jabcb]

For both sides, check the voltage between ground & the movable part of the points when the points are closed and when they are open.

[stinkwheel]

[quote="Alan H"]Check that the points are wired correctly and aren't permanently earthing due to a misplaced washer, also that the condenser on the dud side is OK.
Where are you in the UK?
I'll be working on an early GT185 on Friday.[/quote

I swapped the condensers over just to check and the fault remained on the left but I will look for an earth fault.
I,m in East Sussex by the way,some.distance from Yorkshire! What work are you doing on the gt 185 on Friday?

[stinkwheel]

For both sides, check the voltage between ground & the movable part of the points when the points are closed and when they are open.

thanks for the reply, I will do this, what am I looking for reading -wise? I'm not particularly knowledgeable on this.

[Alan H]

It's a charging problem, so I'm expecting lots of fun!

[Alan H]

For both sides, check the voltage between ground & the movable part of the points when the points are closed and when they are open.

thanks for the reply, I will do this, what am I looking for reading -wise? I'm not particularly knowledgeable on this.

If you have a multimeter on dc volts scale, 1 lead to earth and the other lead to the moving part of the points.
Do the good one first, tgen you'll see what should happen.
You should get close to 12v when the points are open, and 0 when they are closed.
You could swap the wires from the points to the coils so that the wrong points fire the coils to see if it really is the coil.
Also unscrew the plug cap and snip a quarter inch off the ht lead. If that doesn't work, swap plug caps - they can fail too.

[stinkwheel]

For both sides, check the voltage between ground & the movable part of the points when the points are closed and when they are open.

thanks for the reply, I will do this, what am I looking for reading -wise? I'm not particularly knowledgeable on this.

If you have a multimeter on dc volts scale, 1 lead to earth and the other lead to the moving part of the points.
Do the good one first, tgen you'll see what should happen.
You should get close to 12v when the points are open, and 0 when they are closed.
You could swap the wires from the points to the coils so that the wrong points fire the coils to see if it really is the coil.
Also unscrew the plug cap and snip a quarter inch off the ht lead. If that doesn't work, swap plug caps - they can fail too.

OK, will.do that later, I've done the ht lead thing already. Re the lead swap, do you mean extend the black wire from.the rhs points to the lhs points (after disconnecting the white wire)?

[Coyote]

More times than not, the problem is right there at the points. They are way too easy to short out from misplaced washers and insulators. I would set the meter at plain old continuity. Check from the moving point arm to ground. You should have good continuity with the points closed and nearly none when they are open. This is done with the iggy off.. If the meter shows the same with points closed and open, the problem is right there in the pigtail assembly.
185 ec? I don't think I know what the is. Maybe sold in Europe only?

[stinkwheel]

More times than not, the problem is right there at the points. They are way too easy to short out from misplaced washers and insulators. I would set the meter at plain old continuity. Check from the moving point arm to ground. You should have good continuity with the points closed and nearly none when they are open. This is done with the iggy off.. If the meter shows the same with points closed and open, the problem is right there in the pigtail assembly.
185 ec? I don't think I know what the is. Maybe sold in Europe only?

Hi there, I will have a stab at your suggestion, as you say there's a lot of washers and insulators to get correct ! I've just done the 12v test and the lhs side measured 12v open and closed, so I guess your suggested diagnosis is the first place to look??

The EC is basically a c with cast wheels. It's got the little tail fairing on it like a B. My one is a very late reg. 1979. Not as pretty as the earlier ones in my opinion but it was the cheapest way into reliving my 2 stroke twin youth (RD350LC etc).

Cheers

[Coyote]

Man, I love RD's. They have gotten insane price wise though and finding unmolested stock ones is pretty much impossible
My mail man bought a garaged 1200 Sportster for $100.. After seeing it for a year unmoved, he asked if it was for sale. The guy said it was his son's bike but he had moved away and wasn't interested anymore. A hundred bucks and it's yours This no BS. It's a true story.

[stinkwheel]

OK, as I explained to.coyote, I appear to.have a permanent earth on the lhs. Coyote has suggested that I should.check the immediate vicinity of the points which I will do, however are there any other areas I should check before reporting back??

Thank you

[Alan H]

Seems like the points are incorrectly assembled. The wire terminal should be in contact with the spring on the moving point, but not in contact with the little nut & bolt or the mounting bracket.

Looking at the picture following, you can wire the points as I said, or as the diagram, either will work, so long as the nut and bolt is insulated from the mounting bracket. Check those insulators on the bracket - one will be like an open top, top hat and the other should just be a washer which goes over the open top of the top hat, so the bolt is insulated from the bracket.

[stinkwheel]

Seems like the points are incorrectly assembled. The wire terminal should be in contact with the spring on the moving point, but not in contact with the little nut & bolt or the mounting bracket.

Ah, brilliant, will.check out, thanks for.the response!

[jabcb]

Here is a diagram of how the points should be assembled.
There is an additional insulator that you can not see in the diagram — its a small tube that covers the screw threads.