Confirmed.
With electronic ignition installed, I can see the timing bounce up and down with the strobe.
It runs right on the two marks at 3500.
But at idle, it advances at least 20 degrees intermittantly, with resulting surging and stalling.
When you come down from 3500, sometimes it drops down to normal timing (and you get 1200-1400, and sometimes it stays advanced and races at 2000-2400.
If you set the idle at 1400, it will vary between 1200 (when it is running right) and 2000 (when it stays advanced), and is running well enough to get it over to my buddie's garage so we can pull the engine.
Took it out for a good hour, and it has three stages.
One, racing at idle because of too much advance (presumably) - sometimes at high as 2500.
Two, settles back down after 30 mins of riding - a nice solid idle at 1200. Sweet spot.
Three, after 45-50 mins, the idle starts dropping way down and will stall unless you turn the idle screws a good ways up.
So, I start out at one turn in, then have to pull over and turn them in another half after the racing stops, then have to pull over again later and turn them in another full turn to idle from 45 mins on.
This bike is so weird.
The Superhawk from hell...Pulling together my plan to pull the engine and address the advancer.
Couple questions. 1. I see several threads where people try to replace or rebend the springs, rather than removing and replacing the whole unit. Has that worked for people? Sounds a lot less daunting than taking the cam apart. 2. Also, with the electronic ignitions installed, my timing is different in each side. If I am idling at F on the right, then I am firing at LT on the left. And if I put the idle to LF, then I am early on the right. So I set it to average between them. With points, I was able to do them separately. At 3500, both sides are spot on the two marks. So it's an idle issue only. Is this unequal timing also a symptom of the advancer springs? Or do I have another conttibutting problem? sounds like the return springs aren't returning every time its taken to full advance. also perhaps make sure the advance shaft isnt wobbling around inside the cam.
also i read this page awhile back when looking into electronic ignition. the guy has very similar problems to yours. hope this read helps. http://en.allexperts.com/q/Motorcycle-R ... dvance.htm -dave Thanks.
After hours of reading last night, it looks like a lot of people havce had my problem, which is encouraging. It seems like when the bike is cold, the advance is not coming back, but when it gets really warm, it starts operating again. I bought a cheap head off Ebay last night, so I can see how everything is put together and learn how to disassemble the cam without experimenting on my own bike. This should help me get educated before I pull mine. if anyone needs parts from this thing when I am done banging on it, please let me know.
i suppose thats kind of the beauty of these bikes. ive been riding around a 1970 cl350 that also likes stalling randomly but its still a blast and always turns back over. after watching me scrutinize parts upon assembly of my 67 superhawk, my friend tyler put told me, "its not rocket science dave!" and hes right. this is tech from the 60's. if that beezy wants to stall at idle, just tend it with the throttle every now and then.
good luck trouble shooting and take care. -dave
Hi,
That's not my experience. My CB72 can idle all day at around 1000 rpm, The rpm slowly changes from 900 to 1100 and back in "waves" due to the changes in petrol levels in both float chambers, that's all, My cb450 K0 is behaving the same way, only idling around 800 rpm, Jensen assembly of Japanese motorcycles requires great peace of mind (Pirsig)
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