spark? can't keep running long enough to test output

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krogar104

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littleton, Co.
1979 xs650
mikesxs pma and reg/rec
19$ junkyard electronic ignition (was actually like 70$)
http://xs650temp.proboards.com/thread/7899
this is a long tale I'll try to be quick sorry, 4 years ago i purchased this awesome bike, the bike ran well for a bit. solid state gave out replaced with pma. Again ran great left cylinder blew out, replaced all rings and honed both cylinders, best I can get on compression is weak but looks right, after kicking three times both cylinders reach 94psi, messed up bad and used cheap Chinese gasket set. After having everything back together, points were completely off had it running but not well at all. the right point contact was at tdc, while left was 90 degrees after tdc the closest i could get it. I pulled the top end apart again double checked cam was placed right. Went with the 19$ junkyard 180 ignition, still seems like left cylinder is off, I have rotated the engine by hand visual watching the valves countless times. and I'm using the basic chopper wiring diagram for head light, tail light trying both cap which it ran fine on and micro battery.

the bike doesn't want to run at all if the head light is switched off,
and has even more power if i step on the brake switch, confusing me on electrical pull, considering it doesn't seem to have enough power to feed the dual coil for both cylinders, i have tried the gm coil and a couple of scrapyard ninjas i can start the bike but it plays eerie games with me, after i kick start and get it to fire i can stand there it will run, but as soon as i lean over or walk around to test anything it dies, if i give it any throttle it chokes out, i have pulled the carbs and cleaned them multiple times, all passages are clear jets are clean floats are set, diaphragms look good watching them just above idle they both have the same chatter, there seems to be no heat off the left cylinder,

if I lined up the wrong mark on the cam wouldn't i have bent my valves at least?
 
yes the "19$ junkyard" is a 180 degree wasted spark ignition while one cylinder is on combustion spark the opposite has a wasted spark during tdc exhaust, as to of course the stock 360 cam lobe
 
I was hoping an expert would chime in here. It sounds to me like you started with one problem and caused all the others trying to fix the original problem. If I were you, I'd take it back to square 1. Fix your compression, fix your points. Take the time to do it right and it will be faster and cheaper than trying to fix a problem created by taking too many shortcuts.
 
anyone else anyone who might know something about bikes at all I'll explain in "simple"

1.compression is low (94psi) though I can not test with electric starter to build compression does 94psi sound right for kick on three revolutions?

2.on the cam lobe the left point ignition made contact at tdc while the right was 90 degrees after and not 180 since "each" cylinder is supposed to fire at "360" apiece and they both fire at 180 degrees of "each" other every 1 revolution, everything was stock so i replaced with a 180 wasted spark ignition to make sure it fired on both cylinders right at tdc, since there are two marks on the cam could i have placed the cam shaft 90 degrees off and still not bent my valves or put a hole in a piston after running the engine like this?
 
On the compression test you kick it as many times as needed to reach the highest reading. Holding the throttle wide open. Best if done on a warm engine.
On my very first rebuild I misunderstood the book and put the cam in 90 degrees out After fooling with it for a couple weeks I took it to the dealer and that's when I found out I put the cam in wrong. It didn't hurt anything.
On the cam there is a notch in the cam by where the sprocket mounts. This notch goes to the left side of the engine. With the timing marks at TDC the notch points straight up. On the right side of the cam there is a dot or dimple out by the teeth of the sprocket. It goes toward the front and sets level with the heads sealing surface. Where the rocker box bolts down onto.
On your ignition timing you don't time to TDC, You time to the fire marks.
I don't know anything about the $19 ignition. It sounds like too much hassle for the money. A Pamco isn't much more than you spent and is an easy instrall. Takes longer to read the instructions than it takes to do.
Leo
 
Mr. Riggs ignition is not very difficult if you have all of the components and the correct coil (the gm coil). If you are trying to run a different coil it want work very well. I would go back and read his article and start from the begining and re-time the ignition. It is a very good system. Also check your auto advance. This would be the only weakness like Pamco's older system that requires an ATU. I hope this helps. Tony C
 
thanks to both XSLeo and tonyc for the feed back this will be reassuring now that the weekend is here and I can get back to it, the reason I went with Mr. Riggs ignition is because it really is a simple build and if it fails its mostly mechanical with readily available parts plus i want to keep this heap as much of a rat ride, this time I pull the top end off I plan notching out the timing when I can see the pistons, I'm thinking about 5 degrees before tdc is fire so i'll ink mark it when the pistons are between 1/4" to 1/2" before tdc, and I know I've really been ignoring the advance by just sticking a couple of cigarette buts in there so its time to look around town for those parts
 
no but thanks for the reply, before I tore the top end apart the first time I was able to set the points just fine and after nothing, once I converted to Mr. Riggs toyota/gm 180 ignition I tack welded the parts to my timing plate so , its still reversible but I would have to scrap another back plate, as it is I like this system so I don't want to pull the plug and revert just yet, the bike had the firing issue before the change, and I think at this point I'm narrowing it down to....

1.cam is 90 degrees off?

2.reg/rec is no longer putting out the volts?

3.Valve stem seals are garbage that came with the kit from china? I have 94psi compression both cylinders without trying too hard by kick yet I found a puddle of oil in my left exhaust, that's the cylinder that stays cool and doesn't seem to fire.
or all of the above
 
Re-reading this thread, you note when the points 'make' contact. Spark/ignition occurs when the points 'breaks' contact. Or was that what you were trying to say?
 
oh yeah sorry about that I no longer have the points in, but before i pulled them the right point would break contact, and it was only about 45 degrees later the left would make contact, 90 degrees later breaking contact, so the coil would fire at 90 instead of 180, that was with the right at full advance and the left at full retard (that might be visa versa), but that was as close as i could get it.
 
haha no way I even took the magnetic pick up off its plate and place the two plates squarely on the ground, but thank you that's thinking of detail. I noticed hughs 220w pma has to have a micro battery and shouldn't use a cap, I'm using the 200w pma from mikesxs, and I used a cap for quite a while ran pretty well then switched back to stock battery, could have put to much on the reg/rec.
 
Last edited:
You should be able to use a cap with either especially with Mr. Riggs ignition. Are you using a GM low impediance coil? It is imperative that you do.
 
the coil i did not double check on, i just bought the cheapest one for the same year make and model stated in the tut, i believe it was for an 89' cavalier, i'll look into that and see which one, but my repairs are going to have to wait no one in denver seems to have the valve seals or cam seals, so i have some more calling around to do.
 

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