Running on 2 cylinders no spark at right point set

[Guest]

Hi guys I was wondering if someone can help me out with my 1977 GS750. I recently noticed that only the outside pipes of my exhaust would get hot and the inner 2 pipes would get sligtly warm (not too hot to touch after a ride). I figured my coil was bad but I connected it to the left hand point set and saw the spark plug had good spark. I then tested the right hand side point setting by simply opening the contacts by hand and checking for spark.. There was no spark between the contacts when I did this but when I started the bike without the points cover it would spark a lot on the right hand side but kind of in a circular pattern on the points, the funny thing was that I could not actually see the spark from the left hand point set but I know this side works because otherwise the bike would not run on the 1 and 4 cylinder as it does. Anyone know what might cause this?

[rustybronco]

Try swapping the lh condenser for the rh condenser.
how do the rh point contacts look, does one contact have metal deposited from the other contact, or are they pitted bad?

[walt]

Also check the point gap.

[rustybronco]

Also check the point gap.

Sometimes we assume things to be done already... GOOD point!

[Go Mifune]

The points look brand new I replaced them last year. Does the gap matter for testing it since I turn the engine over with the 19mm bolt on the crankshaft until the points are touching? I am not very familiar with points but I did check the gap anyway and it is .015 in. at its widest opening, How do these things work anyway? I mean how do they generate that tiny spark, there is 1 white wire and 1 black wire that go to each point set and run up to the coils. Do these wires carry electric current or do they ground somewhere? What is the purpose of the condensers?
When I did start the bike the sparks on the right hand side point set would move in a tiny jumping jack type fire work movement. Is this 'arcing'?

[GS1000S]

The purpose of the points is to provide a ground for the primary side of the coil. The condensor is designed to store electrons internally when the points open and allow the primary field in the coil to collapse and produce the spark. Condensors do fail occasionally but not often.

I'd start by seeing if you have power to that set of points with a test light connected to that set of points at the studs that hold the white or black wire and condensor lead. If the points are working correctly the light will stay on as long as the points are open and will go out when the points close. If the points are open and the light doesn't come on you may have a wiring problem in the primary circuit. If the light stays on throughout a full rotation and you can visibly see the points are closing I'd suspect corrosion between the contacts. You can clean the contact surfaces with something like 220-600 grit sandpaper. Let the spring tension hold the paper and pull it back and forth cleaning both contact. Then clean the contact with something like brake or contact cleaner and see if you start getting some spark or if the test light cycles on and off when the engine is rotated through a cycle. You can use the set of points that ARE working as a reference. When the points open(and the test light comes on) the coil should fire. When the points close the test light should go out and the coil primary field is charging and becoming saturated in anticipation of the points opening again(test light on) to fire the coil.

Awfully wordy but I hope this helps.

GS1000S

Don't rule out fouled plugs if the bike has been running dead on these holes for a while.

Fresh plugs, cleaned and gapped points should bring them back to life if the points are the problem.

[almarconi]

In order to correctly set the timing on an engine with points you need a timing light and a dwell meter. The service manual should have specs for the point gap and the dwell (in degrees). You can set the initial gap with a feeler gauge. Once you verify that the timing is correct you hook up your dwell meter. Adjusting the point gap will change the dwell. There is a screw that is used to hold the points to the mounting plate, by loosening this screw you can move the point and adjust it. The service manual usually has a step by step procedure to do this.

Whenever trying to troubleshoot problems it helps to approach the problem in a logical fashion with a systematic approach. Did you test your coils with an Ohm meter to see if they are within spec? Is the wiring that connects the points to the coils in good condition? How about your plug wires? Best to sit down with the service manual and go through each system step by step, hopefully you can isolate the cause of your problem.

[rustybronco]

The condenser prevents the arcing across the points by making a place for the current to flow.
without a condenser all the magnetic energy will be consumed in the arc and there will be no spark.
Put the block of the points on the highest point of the cam lobe and adjust to the proper gap (don't forget to properly lube the cam lobe), no real need for a dwell meter, plus finding a dwell meter now a days is difficult.

[Go Mifune]

We're back Mortimer

Well I tested the coil, the wires, the plugs, and the condensers. After all of these things proved to be working I decided to clean the points again this time instead of using the small metal file I was using I decided to take the ol dremel tool to it. I ground the contacts on the points down until they were both level and shiny re-installed them and presto Runs like a champ.
Thanks for your help guys