boyers and coils

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rgrigutis

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ok, i took the points out of my '72 and replaced them w/ a boyer micro mark III that i scavenged off my '74 project. i've checked the wiring at least 10 times. i'm at 31 deg btdc. no start but i do get a kickback occassionally. i rubbed the 2 striped wires from the box together and i get weak sparks from the grounded plug n7yc, ignition wires are new, 12.6v at blue/white.

the coils are old and dissimilar. i'm thinking/guessing this could be the problem. any definitive checks on the coils i can do? what would be good replacements? something that'll last and reasonably priced.

thanx in advance, rick
 
A shot in the dark, but have you timed it to the correct mark, as there are two timing marks on the rotor. One is 180deg. out, which would time it at 31deg. BBDC.
Coils rarely break down.
 
Have you held the plugs with the leads on against the head and then kicked over to verify sparking?
Also, what RPM did the 31 degrees relate to per the instructions, for fully advanced?
 
pston is just b4 tdc at 31 degrees. instructions say set at 31 and set rotor horizontal and stator timing hole should be aligned w/ magnet. check timing at 5000 rpm to fine tune 31 degrees.
haven't checked the plugs while kicking it. tommorrow.
i've got everything wired up temporarily w/ wire nuts and cheapo crimpons to verify that it works and then i was going weathertight.
tommorrows another day
 
Electronic ignitions will work with 12 volt coils but work better with 6 volt coils, as they are wired in series and produce a wasted spark on alternate cylinders. Points ignition operates each coil independently so the wiring to the coils is not the same. I recommend you check that you have wired the new ignition in appropriately for the new setup. Even if the timing is wildly out you should still get a healthy spark when checked with the plugs out, however the bike will obviously not start unless the timing is at least close enough to specification.
 
dave M said:
Electronic ignitions will work with 12 volt coils but work better with 6 volt coils, as they are wired in series and produce a wasted spark on alternative cylinders. Points ignition operates each coil independently so the wiring to the coils is not the same. I recommend you check that you have wired the new ignition in appropriately for the new setup. Even if the timing is wildly out you should still get a healthy spark when checked with the plugs out, however the bike will obviously not start unless the timing is at least close enough to specification.
Click to expand...

I think this post is on the money ;)
The uncertainty seems to be the coils - I'd STRONGLY recommend putting new 6V coils on, and double check the battery is fully fit and fully charged.
Boyers are notorious for being sensitive to volts-drop, and I've only ever run them with 6V coils - -which is what Boyer recommend, I believe (it's too early to be checking my facts here...).
I know from painful experience that they kick back like a...er... kicky-back thing if the battery isn't 100% - If you're measuring 12.6V it doesn't look like this is the problem here, unless the capacitor is clouding the issue.

PVL coils have always worked for me, and they're not overly expensive, but the new Tri-spark ones look interesting too...anyone got any experience of these?
 
I run CNWs Crane single coil conversion. .042" plug gap and as strong a spark as you want.
 
well i8 get an anemic spark when i kick it thru. seems steady on the tim ing side and erratic on the primary side. switched ignition leads and plugs same same. are champion n7yc resistor plugs and might that have an affect? thanx, rick
 
rgrigutis said:
the coils are old and dissimilar. i'm thinking/guessing this could be the problem. any definitive checks on the coils i can do? what would be good replacements? something that'll last and reasonably priced.
Click to expand...

Each coil should have a primary winding resistance of about 2 ohms, thus 4 ohms total. If one or both coils is designed for 12 volts (instead of 6v) it'd make a huge difference.

There are aftermarket replacements of Lucas coils on eBay all the time at reasonable prices.
 
B+Bogus said:
PVL coils have always worked for me, and they're not overly expensive, but the new Tri-spark ones look interesting too...anyone got any experience of these?
Click to expand...

I've been using them for a few months now. They fit and feel just like Lucas, except that they weigh about twice as much. I haven't done a side-by-side check of spark intensity but it looks good. Very nicely made (and they polish up pretty :D )
 
ok, i wired red and white from the box directly to the bat. started on the 4th kick but really kicked back. unable to fine tune the timing 'til tonight when wifey get home. won't she be thrilled to run it up to 5000 while i twiddle w/ the stator plate. i ran it up and down the street and it died on one of the turn arounds. restarted after a couple kicks but kicked back at me again. what's the frequency supposed to be on the kickback? from what i read it sounds like it kicks back only rarely. can anyone reccommend a good resistor plug? i'm hoping w/ the timing fine tuned that the kickback will dissappear and the starting will improve. i plan to run the red back to the bat for good. but i'm going to have to go thru all the white/blue and white connections and clean them up.
 
Properly installed/timed, the Boyer gives no kickback in my experience, and (all other things in tune) makes starting a 1-kick affair.

The other secret is:

boyers and coils


Where NOT twisting open the throttle in kicking through on a cold start -- but holding it spot on -- changed my whole world
 
I will agree with that. I have had a Mk.111 on mine for years. The bike will start 1st kick even after months of not being used. It never kicks back. The only difference between points & a Boyer, is that the motor feels a bit smoother.
 
well i finally got the boyer wired w/ weather tight connectors and timed at 31 degrees at 5000. he starts 2nd kick, no kickback now, idles a lot better but these 930's are so bad! got a couple of jrc 30mm coming next week.

got a new problem now. no power going up hills and from 2000 on it just revs to 4000 w/ no power almost as if it was disconnected from the drive. clutch slipping? don't think so as it never did that b4 the boyer. i'd moved the needle clips about 3 weeks ago and it was running strong, really pulling all the way thru 5000. anybody have any experience w/ this and anew boyer? i'll recheck the timing tommorrow and experiment w/ the needle clips tommorrow and do some plug chops but right now the plugs are a perfect tan. thanx in advance, rick
 
If you're putting out 4000 RPM, you should be doing ~70mph since you have hard gearing (except for the clutch discs). So it does sound like a slipping clutch unless i I misunderstood the symptoms you describe.
 
From that description, it does sound like clutch slipping. You should probably remove and inspect the plates. Maybe they're oily and a mere cleaning will fix things, but your symptoms do sound fairly extreme. Good luck.
 
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