How to test Points system?

[brainrush]

Hello, I am new to the forum, I tried searching first, but I couldn't get the result that i wanted, so here it goes:

First, a little background:

I have a 1978 GS 550 E with the VM22SS carbs and points style ignition system. I bought the bike as a restoration project, it had been sitting for less than 2 years, and having rebuilt the engine (Cylinder #4 had some surface rust, and the starter motor was toast).

The Problem:

Now that I have it all assembled, I need help figuring it out how to get it started, I've never worked on an engine with a points style iginition, and the only carbs I've ever tinkered with have been on weedwhackers and model airplane engines. Could it be too lean to start (it looks like the previous owner installed an aftermarket exhaust and pod filters)?

As for spark, I have no idea how the points system is supposed to work, but according to the diagram in the service manual, it looks like the points and condensor are wired in parallel to the ground and the coil, but it doesn't make sense to me, with the battery disconnected and the ignition set to off, no matter when I touch the continuity tester along the ignition circuit and ground, I'm still getting continuity, is this normal?

I'm not new to motorcycles but the 98 BMW I have is fuel injected (and sounds like a vacuum cleaner) so any advice, tips or tricks to help diagnose the problem (my bet is ignition), would be much appreciated,

-thanks

[Suzuki_Don]

When testing it all depends on if the points are open or closed. Connect the continuity tester to the moveable side of the points, not the fixed side as they are earthed all the time. Then rotate the engine abd look for the tester fluctuating between open circuit and short circuit. This is the starting point. Report back on your findings.

P.S. WELCOME to the GSR Suzuki site.

[brainrush]

there must be a short somewhere, because I seem to be getting continuity all the time, even when I deflect the points manually, and the entire assembly is off the engine (but still connected). although the breaker for cylinders 2/3 sometimes seems to perform as it should, but only occasionally, I'll be able to get about 10 successful breaks in a row, and then it'll go back to being a solid beep all the time for the next 5 minutes.

[Suzuki_Don]

there must be a short somewhere, because I seem to be getting continuity all the time, even when I deflect the points manually, and the entire assembly is off the engine (but still connected). although the breaker for cylinders 2/3 sometimes seems to perform as it should, but only occasionally, I'll be able to get about 10 successful breaks in a row, and then it'll go back to being a solid beep all the time for the next 5 minutes.

Use an ohm meter if possible. Remove points from base plate and check all insulating washers are in place and there is no dampness anywhere on the backing plate or the points. Place a piece of paper between the point contacts (both sets) when you reassemble them and connect the test instrument from the moveable side of the points and the other lead to the fixed (earthed) side of points and you should have an O/C on both sets of points. If there is a S/C then there is a leak to earth somewhere on the moveable side of the points. Probably an insulating washer left out.

[Killer2600]

No one answered how they work so I'll tell ya.

The points are obviously on the ground side of the coils primary circuit. The points themselves make and break this connection to ground.
When the points are touching, a path to ground is complete, and the coil charges.
When the points break contact, the path to ground is interrupted, the magnetic field in the coil collapses, and the spark fires.
The condensor is in parallel with the points, it's purpose is to prevent a spark jumping across the open points and burning them. The reason behind the arc is the same principle thats behind the spark at the plug, a collapsing magnetic field in a coil produces a momentary high voltage spike with voltage strong enough to jump gaps.
The condensor absorbs the energy, and charges like a battery, so that the spike doesn't jump the open points. When the points close and give a path to ground the condensor discharges while the coil is charging.

Hope that sheds some light on the subject.

If your seeing a constant path to ground, you should disconnect the condensor and see if your constant ground goes away. A shorted/bad condensor will cause such symptoms, as well as other parts touching ground when they shouldn't, although the condensor is a common one that's not visible to the naked eye.

[Big T]

Carbs - yes, they need bigger jets and tuning for pods and pipe. What sizes are in there now? Where are the needles set?

Points - Points are an ancient technology that are designed to deteriorate and burn up. They work by breaking a circuit when the points open, which causes the coils to fire.

While I'd recommend getting new points and condensors (condensors deteriorate with age), once you price what two new sets cost, you'll want to just buy a Dyna S electronic ignition for about twice the price and be done with points and their maintenance and replacement forever.

The point sets in your Suzuki are crap compared with your old small block Chevy, partially due to the rpms involved.

I've owned my blue 78 for 30 years, went from stock points to a "trick" plate with Chevy points to a Dyna S 25 years ago. I can't remember when I last checked my timimg.

[brainrush]

Ok, so with the pieces of paper inserted, and just checking across the contacts, I get an open circuit, no paper, closed circuit, now the points definately don't look 40,XXX miles worn, so it's got to have been replaced at some point, so I'll be snooping around a little more and looking into finding out If I'm missing those insulating washers, thanks again

*UPDATE*

Ok, I checked everything out, and i noticed that the breakers were attached with e-clips, followed by two washers, and then the breaker itself, onto the shaft, figuring I had nothing to loose, I changed the order to washer, breaker, washer, e-clip, and using a piece of paper on the opposite breaker, I was able to set the timing as per the manual. I removed the #4 plug, and tried to check for spark, but it's hard to look at a .030" gap whilst trying to kick start, so I settled for thinking I saw a spark and proceeded to try and push down the driveway.

So, into second gear, clutch in, PUSH! PUSH! PUSH!
drop the clutch
flub...flub...flub...flub...flub... said the dead pistons as I forced them into motion

As I got closer to the end of my driveway and onto the street, I gave it an extra PUSH! PUSH! PUSH!! and the flubbing sped up, finally, I ran out of room so in went the clutch and on went the brakes.
as the motor was winding down I heard this:

flub...flub.......flub..........flub.............f lub..................POP!!!!

AHA!!! a breath of life from this dirty old demon, I'd do another run, but seeing as the ambient temperature right now is around 100 degrees (Near 38C for those of you across the pond) I think I'll wait until a little later tonight.

[brainrush]

so the bike is now occasionally popping probably 1 of 4 cylinders, so it's slowly starting to get some life, although each run leaves me gasping for breath.

the condensor itself looks new, it still has that bright plated finish on it, but I don't know the technology behind a condensor, and almost thought of running a magneto for a bit (hey, if they work for cessnas) but I'll look into a Dyna S if it turns out to be a garbage condensor.
As for the carbs, I haven't really explored them yet, but when I first took them off the bike they were filled with this green fluid, it looked like simple green, so I sprayed them off with some carb cleaner, inspected the bowl of one of the carbs, saw that the floats were in good shape an that there was no oxidation and no visible build-up, and assumed everything was good.

Looking at how the rest of the bike is put together (for example the side panel used a welded in bolt as a securing mechanism), I'm guessing he didn't do jack to the carbs and let them be their lean selves as he put on ill fitting filter pods(don't exactly clear the frame) and an exhaust that uses one non-metric screw to attatch to the head. As for the rest of the bike, all the gauges but the speedo are missing(although the speedo is missing its housing), and the tach gear on the cam is chewed up quite throughly. the rear indicators are from the front of an R6, painted in a "carbon fiber" checkerboard pattern. all the wires coming from the rectifier are white, except for one red one, so I assumed their phase position for now. this bike was treated like a dog by it's previous owner, so I'd be happy to see it just run (the paperwork is another story), thank you guys so much for your patience, and I'll keep posting problems as they turn up.

[Suzuki_Don]

Just a couple of observations. If you intend to replace the tach gear first of all remove the cam cover and check the skew gear on the exhaust camshaft that drives the tach gear. On my 550 it was really chewed up on the camshaft.

Do you have an analogue ohm meter. If so you can check the condensors. When connected the ohm meter will give a really big kick to about 1/2 scale and then return back to zero, from whence it came. This proves the condensor OK. If the needle flicks to the opposite end of the scale and stays there, then that indicates a short circuit and the condensor is toast. If the needle kicks to 1/2 scale and does not return to zero, even if it's only a few degrees, that means that the condensor is on the way out.

If you don't have an analogue ohm meter then just buy new condensors, they are not that expensive.

If you have not removed the tank then take it off now to give you some working space. Remove all spark plugs, leave the HT wires attached to them. Lay them on the cylinder head/valve cover. Get a 12V battery (does not have to be a motor cycle one) and crank the engine and check for spark at the plugs. Record what is happening with each plug. You need to be methodical to sort the issues out.

While the tank is off make sure all connections to the coils are good, clean or reterminate if necessary. Check the wiring to the coils and points against the wiring diagram to make sure everything is as it should be. It would not be the first time a bike would not start because the wrong cylinders were firing at incorrect time in relation to valve opening and closing.

[old_chopper]

I have a gage set (speedo-tach) off a 1980 GS550L I am not going to use. The odometer has 1394 miles on it so you could have a low mileage ride! PM me if you're interested.
OC

[Big T]

It won't start because the carb jets are clogged up.

Go to the Garage, Carb clean up page and follow carefully.

I'm betting most of your cylinders aren't getting gas ,check the plugs.

You can test this theory by applying starter fluid and pushing again. But, brains over brawn, tear down the carbs

[brainrush]

ok, so you think a good carb cleaning is in order? because after a few attempts at push starting it definately smells like gas. I accidently left the ignition on last night, so now the multi-meter is reading a measily 2.5 volts, I'll try out my battery tender tonight, if I don't get anywhere with it, I'll taking it into the place I bought the battery from as they'll charge it free of charge (pun intended).

Hmmm, I guess that gives me tonight and possibly tomorrow to give the carbs a good cleaning....