Anyone here use a Power Arc ignition?
- Thread starter Mongrel
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Yes I have the paperwork. I knew that Old Britt’s sold them for Commandos, so thought this would be a good place to ask. There wasn’t anything in the paperwork or on the Power Arc website about the fact that the optical disk counts the # degrees rotation regardless of the direction of rotation. That means the Power Arc setup probably isn’t the best choice for a cantankerous 500 single without an electric starter. I did eventually figure out the starting drill after doing some research. The single has a much greater tendency to roll back a bit even when slowly kicking it through.
The problem now is that it doesn’t want to start. Using a paddock starter, the engine won’t fire until you turn the kill switch off and then back on again. Then it will fire a few times and die. Turn the kill switch off and back on again… it fires a few times and dies. It’ll do that until you give up.
It did it once before and I used a scringe to squirt some alcohol onto the optical lens, blew it out with compressed air and let it dry overnight. The next day it ran fine. Not sure what if anything was on the lens. The unit was purchased new and has about 12 kilometres on it. It’s mounted in a Norton twin housing which is properly sealed, so the unit is clean and still looks like new. Basically ran fine for a few kilometres and back to square one.
The outer portion of the optical pickup is held on by a small Phillips screw. Can that part of the pickup be safely removed for cleaning? Assuming that’s the issue?
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I ran a different system for a few years that ran an optical pickup, if you were adjusting it and left the cover off then on a sunny day there was too much extra light and it did not fire. Closing the garage door had it working and I could use the strobe to adjust.
The Power Arc is a multi spark setup, so you do not get a single spark that you can strobe time off.
The Power Arc is a multi spark setup, so you do not get a single spark that you can strobe time off.
Yes.. I use a piston stop and a degree wheel to establish TDC, set the light and pray the program does what it is asked to do. One of the main reasons that I wanted something that was programmable is that I’m using a twin plug head and wanted a way to back out a bunch of advance. At the moment I’m wishing I had spent the money on a mag.
MikeG
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The only time I've had issues was after washing the bike (happened twice) must have sprayed enough water at the cover to force some in. Pulled the cover and shot some compressed air in an all was goob. Been caught in some really hard rain storms and never had a problem. Don't know if this helps you or not but ?
I don’t think anything is getting into the distributor. There is a new lip seal on the engine side and a new O-ring on the cover. The hole/grommet where the wires go through wouldn’t be a perfect seal, but the bike is in a heated garage or basement when not in use. I’m just doing the first few shakedown runs (since the bike was completed) I’m only talking it out when the sun is shining. I’ll try cleaning the lens again and see what happens. It just makes me want to keep my riding within pushing distance of home. There is a blurb on his website that mentions cleaning with alcohol, but wondering if there is something better that is safe to use.
It’s a single cylinder, twin plug setup. I don’t think there is much difference. It’s a CD-L2, so used on both singles and twins. Had I known ( it’s not in the instructions or on the website) that the system calculates rotation regardless of the direction of rotation, I probably would have bought something else. Ok for a twin, but not so great for a single. I can live with that part, but the no start thing is a bit annoying. I cleaned the optical lens again and will try starting it tomorrow.
cyclegeezer
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Do you have a compression release? If I remember correctly, the Power Arc has to make a full revolution before it starts firing. You could pull in the release and kick the bike through a couple of strokes to arm the ignition, then sneak it up close to TDC, pull the release once again to get just past, and then give it a good stroke through. I have one from Old Britts on my '74 850 and have never had any problems with it, but I have a CNW e-start that I use more often than the kickstarter. The routine I outlined is what I do to start my Royal Enfield 500, but it's on points.
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kill switch: have you wired it direct from battery to eliminate kill switch, as a try out?
Yes it has a compression release. Now that I know that the module includes backward rotation in its calculation, I can kickstart the bike. Still not the easiest, but that’s due to age etc. Right now I have the primary cover off so I can see if it rolls back at all.
No. When I discovered it would only run for a few seconds after cycling the kill switch off and on, I contacted Power Arc, to ask about it, but never got a reply. I did find a blurb in their troubleshooting section that sounded like it could be something on the optical lens. After spraying it with alcohol, it fired up and ran ok for a while. I’ll try starting it later today… lens was cleaned yesterday, but it looked absolutely pristine inside there.
Point taken about the kill switch. The switch is new and the lens cleaning worked albeit temporarily, so I still think that’s the issue. Next time it acts up I will bypass the switch. I didn’t think about the switch and I should have… I’ve been there before.. thanks for reminding me.
MikeG
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I was going to mention this as well. It has to see TDC once to know where its supposed to spark. With my Commando on a cold start its key on, slow kick through 2 revolutions, then prime and kick it over like you mean it. never any kickbacks. Once warmed up it doesnt seem to care.
BTW, I should have also mentioned that when the cover is off and you can see the belt, it quickly becomes evident that it isn’t just rolling back against compression. The compression release forces the follower away from the exhaust cam. That still means that the engine wants to roll backwards when the intake valve is opening. It may sound a little surprising, but the intake valve spring will cause the engine to roll back approximately 10 degrees. I can also work around this, but it just adds another layer of complexity to the kickstarting process. Plus… if I run the bike with the primary cover on, I don’t really know if the engine has rolled backwards from spring load on the cam until it tries to shatter my ankle. Obviously (at least to me) that this system is really meant for multi cylinder engines and not a good setup for singles and there are better options out there.
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I installed one of these on an Enfield single and if I followed the starting procedure to arm the Power Arc it would start right up with little fuss. BUT I was never able to get the owner to understand and use the starting drill. We had reverted to kick starting after a backfire from the previous electronic ignition destroyed the starter gear train. Had he left it stock a great deal of grief could have been avoided.
I can kickstart the bike now that I figured out the drill. I think it’s a little disappointing that the manufacturer never mentioned the problem with the engine rolling backwards. The only time I can’t kickstart the thing is when the optical lens decides it doesn’t want to cooperate.
This project began with a set of empty Comet crankcases and the remains of a Honda GL 500 I. There was no mag, so at the time, the Power Arc seemed a reasonable way to go. The selling feature was the ability to program it myself. I needed a way to rewrite the advance curve for the twin plug setup. If there had been a mag in the pile, I wouldn’t be here now. I’ve been looking around for a mag just in case I lose my patience with the Power Arc. The fact that I can’t get a response out of the manufacturer kind of sucks…and I’m not alone.
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