Poping and erratic running there then gone.

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Fast Eddie said:
A blocked tank vent was mentioned back in post #7....

Any confirmation of this ?
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Yesterday, sitting by the side of the road, I opened the cap multiple times, the old random approach, and even checked that fuel ran out of the taps (I had a screw driver with me to take off the fuel lines). Kicked and kicked and then just sat there on the bike calling my son. Then, after a while, gave it one last kick and, like magic, it started and ran like nothing was wrong at all. Started to settle on a possible electrical fault. Some one suggested switching out the Powe Arc for the old Boyer MARK III. But, the bike was second hand and it ran like crap with the old Boyer (something was obviously bad, or fried, in the Boyer) but ran/runs great with the Power Arc -- except the optical sensor records as degree rotation even slight, perhaps even unnoticed, kickbacks. So you have to be careful when kicking. If I switch it out with anything it will be a mag. Had one years ago on a '66 750 Matchless frame/Norton engine. Monoblocks. It was always tickle-kick-start. With battery, without battery (who needs lights). That big damn machine started running and I was 18 years old. I look back now and just shake my head that I'm still alive.
 
It sure sounds like an electrical issue , have you tried switching plug wires .... coils can be a bugger if overtightened some need to get hot before misbehaving , even if you see spark on engine case grounded spark it might not fire when in use , first make sure good plugs , then leads , then coils .... if all good for sure begin checking your connections working back from what you know for sure is good ...
 
You’re running a Mikuni right? Mounted on a rubber manifold right? Thus isolating the carb from the engine...

It ain’t fuel vaporisation (whatever that actually is).

I’m starting to side with those saying it’s a coil breaking down when it gets hot.
 
Oh this is the magic ignition... Now I remember the earlier discussions. Flush the MIK and go buy an inline filter(one of the clear ones), check those coils, & if you've still got issues then take that unit off and go for a conventional EI before you have a heart attack fighting this thing. There may be a little trash enhancing your problem, but getting all warmed up and performing fine then misbehaving doesn't point towards the carb. It does point toward that ignition by cooling 15 minutes or so and then starting up running fine until the next time it sticks you.
 
Feel the coils and even carb body when this next happens to determine if particularly hot. I had an amal carb on two into one manifold get too hot to touch within moments of shutting down for fueling. Your mikuni shouldn't get that hot if on the rubber mount. Solution in my case was putting another phenolic insulator gasket between carb and mani.

If coils are over heating they may need replacing.
Also check if coil clamps too tight which some report can deform casing enough short out internally maybe heat causes enough distortion to short in your case. Wrapping coil in electrical tape where clamp touches to insulate body from ground.
 
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jbruney said:
Oh this is the magic ignition... Now I remember the earlier discussions. Flush the MIK and go buy an inline filter(one of the clear ones), check those coils, & if you've still got issues then take that unit off and go for a conventional EI before you have a heart attack fighting this thing. There may be a little trash enhancing your problem, but getting all warmed up and performing fine then misbehaving doesn't point towards the carb. It does point toward that ignition by cooling 15 minutes or so and then starting up running fine until the next time it sticks you.
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Check to what you wrote. Yesterday I kicked that thing so much it was like I ran a mile -- on my right leg! And passerbys would wonder why some guy lay down to take a nap next to his bike.
 
FWIW, I once ran into a (car) coil issue that caused the ignition to cut out in an aggressive left turn. No problem in right turns and no problem with normal left turns. We fitted a new coil which solved the problem but to be sure it wasn't some sort of electrical connection issue that we accidentally fixed when installing the new coil, we then reinstalled the old coil in the same orientation and once again it cut out in aggressive left turns.

Coils can do some odd things! ;)
 
I would also suspect a bad connection somewhere. You'll have to check them all on the side that goes on the fritz. A blade connector can be slid in alongside the female rather than in the center and locked. Will still work-sometimes. Also, any original metal barrel connectors should be replaced as they tend to disintegrate inside their rubber sleeves.
 
To all above: all the advice above is good. Just this, the coil(s) come in a package setup from PowerArc. That includes the op amp electronics that calculate when it should fire. It's about a 5x5x2 inch block that has the switches for two different types of fuel and two different spark advance power curves (giving a total of four possible curves). You can also design your own power curve and program that in. Still only four possibilities, but one is of your own design. Have thought I'd program one for the easiest never kick-back starting. If I knew how. Once started you would only need to reach down and flip the switch to "normal running" once it's running -- and your leg is safe. So I'm not looking at standard out in the open coils. That said, they still could be bad. Ps. I have another ignition coming. Bit the bullet. Will report on my findings when I get it. Also will ask the people at PowerArc what they think.
 
Talked to PowerArc. They said it sounds like heat causes a corroded connector to get worse. To diagnose, carry a jumper to go from ground (positive on the battery and frame) to the positive ground terminal on the Power Arc module. Thus, bypassing the kill button and hot wiring it essentially. If that cures it right off the problem is corrosion in old wiring and old connectors. If not, call him back.
 
An exorcism is in order.... Demon in there somewhere.

Had my misfortune today also... Gave up on the speedometer repairs/replacement, and just did a GPS setup. Well got it all in there and right off the bat, whilst snugging up the cap bolt on top of left fork leg with that big ole box end wrench...…. It slips and I break the glass.... It survived in working order though. Think I'll silicone some plexiglass and be done. Figured I'd let you know that my boat also leaks..... Sometimes sacrificing a choice lamb could be beneficial.
 
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Joe Schlaberdowski said:
Talked to PowerArc. They said it sounds like heat causes a corroded connector to get worse. To diagnose, carry a jumper to go from ground (positive on the battery and frame) to the positive ground terminal on the Power Arc module. Thus, bypassing the kill button and hot wiring it essentially. If that cures it right off the problem is corrosion in old wiring and old connectors. If not, call him back.
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“Take two aspirin, call me in the morning”

The hotwire is a good acid test.
 
jbruney said:
An exorcism is in order.... Demon in there somewhere.

Had my misfortune today also... Gave up on the speedometer repairs/replacement, and just did a GPS setup. Well got it all in there and right off the bat, whilst snugging up the cap bolt on top of left fork leg with that big ole box end wrench...…. It slips and I break the glass.... It survived in working order though. Think I'll silicone some plexiglass and be done. Figured I'd let you know that my boat also leaks..... Sometimes sacrificing a choice lamb could be beneficial.
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I do like lamb.
concours said:
“Take two aspirin, call me in the morning”

The hotwire is a good acid test.
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When you're stuck alone twenty miles from home it'll take more than two aspirin to make you feel good again lol. And then when you've all but given up and the bike starts you become very religious and start praying and promising to give up your wicked ways -- if you can only make it home!
 
Been a while, but I shall have to support the single malt motion because it helps bring about an inner peace of the soul in times of stress....
 
Called PowerArc. Was told: After 1/4 second! The ignition reverts to TDC firing. Thus it is wrong (and, dangerous in my opinion with a banged tibia that still feels the "touch" of a kick back start lever) to kick it hard to start it. You give it a prod to get it close to start feeling the compression, and then "gently kick it over". No high rotation rate to get spark. That first spark is set at TDC -- ALWAYS (1/4 second to a reset to TDC). In fact, there in lies the danger. If you give it the traditional hard kick and that kick does not result in a start, but goes round to the next compression stroke TOO SLOWLY (there wasn't a very good charge of fuel and air the first time over, OR it didn't fire the first time over, but just pulled a good charge into the cylinder, it will fire with standard advance!! And THIS time it Can kick back! The advice was as soon as you give it a nice little kick, GET YOUR FOOT OFF THE KICK STARTER! So I have a good piece of advice for Power Arc. All the problems (and the danger!) could be fixed if it could be programmed to stay at TDC firing for TWO ROTATIONS instead of one. If TDC firing was enough to get it through and over compression from the first firing through the second, now with regular advance, it will work for the second rotation as well. So even if you kick it so hard it goes round a second time with a weak or even no firing the first, the second won't backfire and kick your foot off. You could even program the ignition curve to stay at TDC (NO possibility of kickback) until you flipped the switch to the second, normal curve. But that's not the reality today. So GET YOUR FOOT OFF THE KICK START QUICK! As to my problem getting stuck in the middle of nowhere? Carry a jumper wire for diagnosis and possible cure as described above.
 
Joe Schlaberdowski said:
Called PowerArc. Was told: After 1/4 second! The ignition reverts to TDC firing. Thus it is wrong (and, dangerous in my opinion with a banged tibia that still feels the "touch" of a kick back start lever) to kick it hard to start it. You give it a prod to get it close to start feeling the compression, and then "gently kick it over". No high rotation rate to get spark. That first spark is set at TDC -- ALWAYS (1/4 second to a reset to TDC). In fact, there in lies the danger. If you give it the traditional hard kick and that kick does not result in a start, but goes round to the next compression stroke TOO SLOWLY (there wasn't a very good charge of fuel and air the first time over, OR it didn't fire the first time over, but just pulled a good charge into the cylinder, it will fire with standard advance!! And THIS time it Can kick back! The advice was as soon as you give it a nice little kick, GET YOUR FOOT OFF THE KICK STARTER! So I have a good piece of advice for Power Arc. All the problems (and the danger!) could be fixed if it could be programmed to stay at TDC firing for TWO ROTATIONS instead of one. If TDC firing was enough to get it through and over compression from the first firing through the second, now with regular advance, it will work for the second rotation as well. So even if you kick it so hard it goes round a second time with a weak or even no firing the first, the second won't backfire and kick your foot off. You could even program the ignition curve to stay at TDC (NO possibility of kickback) until you flipped the switch to the second, normal curve. But that's not the reality today. So GET YOUR FOOT OFF THE KICK START QUICK! As to my problem getting stuck in the middle of nowhere? Carry a jumper wire for diagnosis and possible cure as described above.
Click to expand...
Have you thought about fitting elektronik saches or Lucas Rita ?
 
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