I have read the past posts on this subject. I will try unplugging and reconnecting every connector on the bike, but I am sceptical - I rewired the ignition not long ago and I think everything will be nice and tight.
My bike failed TODAY, so I have the symptoms fresh in memory. It started on a stretch of motorway where the bike just missed a beat every 100 yards or so. I stopped, drained carb, looked at plugs, all okay. After cooling down, bike rode fine. Then longer periods of misfire interspersed with good running, finally getting quite dramatic before cutting out altogether. Its not battery which is still up and lights are strong. Whole failure process took about 50 miles from the first one-beat misfire to the complete no-sparks situation.
I had a similar problem with my Norton. Check the solder where the two wires hook to the pick-up plate. I found both broken completely off. The bike sputtered a bit and then completely died. I know that can be a problem with the Nortons. Although I believe it rare in Triumphs, I suppose it is possible. Check these wires at the solder point.
I had a lot of trouble with my t100 after i rebuilt it and rewired it , it would splutter along and pop and backfire, i checked the ignition timing about a dozen times , checked the wiring connections endless times and the misfiring still persisted ,i assumed it was the Boyer malfunctioning, Before i finally took the Boyer box off to replace it, i checked the wires again and discovered a wire had broken inside its insulation and was passing the continuity test with a multimeter. Maybe double check every last inch of the wiring in your ignition system and send the Boyer box back to Boyer for testing.
In situations like this, I prepare a length of cable that can reach from battery -ve (assuming standard +ve earth) to the last connector before the supply enters the e.i. box. I include a fuse holder in this cable, I fit the cable to the battery but put the fuse in my pocket and go for a ride.
If the bike starts to misfire, I stop, disconnect the e.i. box from its supply through the ignition switch, kill switch, etc., connect it to the supply direct from the battery and install the fuse from my pocket.
If the bike won't restart, or restarts but the misfire returns, your problem lies in the e.i. box, trigger unit, coils and/or the connections in between. If the bike restarts and runs happily, the problem lies somewhere between the battery and the e.i. box.
Nevertheless, a list of specifics I'd check, in addition to the other suggestions:-
1. Connections between trigger unit and 'box'.
2. Earth from 'box' and second coil +ve (assuming +ve earth). The B-B instructions leave you assuming you can connect these just anywhere; I advise against this - connect them by dedicated earth cable(s) to battery +ve (assuming ...).
3. Replace fuse, especially if you're still using the cylindrical glass-'n'-metal ones. Check fuse holder terminals.
4. (Intermittent?) high resistance across the ignition switch. Don't forget to check while wiggling the key up and down, especially if you have other keys and/or a fob on the ring. Also check for intermittent high resistance across any kill switch.
Don't worry over, points, especially after market ones, can be an equal opportunity inconvenience. The time could come when the plastic points arm block pre-maturely wears (or worse melts) and your timing changes... Is a seized piston enough to make you feel that you haven't been left out.
Copy your volt drop post here. It is especially relevant for people diagnosing electrical failures, especially when an electronic ignition is involved. It is the way it is done professionally!
The one thing that you must include is placing a jumper between the Boyer white wire and the Boyer black wire to create a circuit. Don' forget to measure for voltage at the Boyer red wire (ground positive ground systems). Any voltage their indicates a bad ground. The difference between open circuit battery voltage and measurements taken around the ignition circuit should be less than a few milli volts.
Most times these symptoms turn out to be wiring issues. Stuart's jumper cable idea is a goodie. As important as the feed wire, is the battery ground wire, as the circuit must be complete. I've seen it where a bike will run with the most crazy symptoms but will go Ok if points are swapped back into it. However 50 miles down the road, the real fault shows up. Typically a frayed wire holding on by a single strand or two, finally lets go completely. Please inform of the outcome.
For what it's worth, my experience: my stock '69 TR6R has points, never had a problem. My Bitsa 650 runs Boyer, no problems so far in 18 months of operation. Following suggestions on the forum, I recently re-wired the Boyer so that the ignition circuitry is totally separate from the rest, with its own fuses, switch, and relay.
I have not had any issues with the MKIII (save a loose spade on a coil jumper wire once) these past seven years. I recently replaced my crank and ex camshaft seals in the timing cover. The "points" wires were work-hardened and I did find a break in the insulation on the BY wire just where it enters the black tubing/oil seal in the cover.
While it hadn't caused any issues, I'm certain it would have just been a matter of time, so I replaced the whole BY/BW "points" sub-harness as a matter of course...
'77 T140J "Vintage Bike". What's in your garage?
"The paying customer is always right."
Fitting round pegs into square holes since 1961...
At John's behest, and at the risk of telling you something you know already, from my contribution to the "Loosing voltage" thread on the British Motorcycle in General Board:-
Volts is the difference between two points in a circuit. If you want to measure Voltage drop:-
1. You must measure the Volts at a starting point - the battery, say, by placing the end of each meter lead on a different battery terminal. The meter reading indicates the difference in Volts.
2. Leaving one meter lead attached to a battery terminal, move the end of the other lead to another point - the last terminal before the wiring enters the e.i. 'box', say.
When conducting this test, it's important to know the earth/ground of the vehicle. Most British bikes are 'positive earth/ground' so, at 2., the meter lead you move off the battery is the one attached to the negative terminal.
When you attach that lead to another point - the last terminal before the wiring enters the e.i. 'box', say - the difference between the new meter reading and the one you got at 1. is the 'Voltage drop'. On a motorcycle, the cable runs are so short, voltage drop should be almost undetectable - on an analogue meter (needle waving over a scale), the two reading should be the same; on a digital meter, you'll probably see different figures but, if the difference is more than about 0.25V, you need to investigate.
I had a very intermittent missfire problem on my T100R with Boyer which dogged me for nearly a year until it finally killed the engine altogether and I had to be recovered. Most times up to then it was just a temporary miss or a backfire. When it did stop it normally cured itself by the time the tank was removed. The problem was one of the coils. The shellac from the winding had not been removed where it was soldered inside the terminal post at the factory. A careful solder job cured the problem permanently. This sounds as though the symptoms are similar to yours.
If the points close up from a 15 thou gap you would retard the engine by about 15 degrees and after this the engine wouldn't run because the points wouldn't open. The worst you clould do is run at a max advance of 23 degrees. Would this damage the engine or just cause a bad power loss?
Just my , but I've never seen any advantage to electronic ignition. I have it on two bikes (I bought them that way), and one of them ('70 Bonneville) is a PITA. If the battery isn't FULLY charged, the bike runs like crap. My points bikes all pretty much just run, even without a battery, as I have capacitors on most of them.
Why go to all the trouble of converting a perfectly good system just to create a whole different set of issues?
Yet many seem to like it, so to each his own, I guess.
When i fitted a Boyer to my triumph 500 , i noticed immediately the bike ran better , picked up off the throttle better and started much better, especially on cold mornings. People always make the point of the boyers going to full advance when the battery is not up to par , but the fault lyes with the battery not the Boyer, and points being mechanical require constant maintainance, think how much trouble the factory had with them.
I don't suppose that the Boyer going to full advance when the battery is bad really matters at all. With an old manual advance lever it was, apparently, left on full most of the time anyway. The auto advance has no curve, rather it just advances the ignition to full as if you were pulling the old lever. The bike does idle better retarded. It would hurt the engine if the timing wasn't set correctly in the first place, I suppose.
I agree with the previous poster that when you change to an electronic set up you just have a new set of problems.
To complain about having to maintain the old auto advance is crazy. You only have to put a drop of oil on it maybe every 2000 miles! Some people don't ride that far in a year!
Morn'n all,interesting that several people mentioned failure of the magnets. I also had this happen after many miles of service. The points system is probably the best for the average BB owner,however,if the bike is to be really ridden long distances the points that are available today won't cut it. As John mentioned,the rubbing block on the contempory points supply seems to be make of cheese. When I was traveling across the country on my first trip,I was adjusting the points daily as they closed up from the long days and the heat. With the Boyer installed,the problem was completely solved.The Boyer was new at the time so I carried a spare EI as I wasn't as secure with the newfangled system as I am now.Anywho,my advise,(if anyone asked)would be to go with the points if you are just riding a few thousand miles a year,but if you ride hard and fast,go with the EI igniton. Dick
I've been stranded three times over the years, and it was always with the Boyer system. I don't use them anymore. Good advance springs and a drop of oil once in a while will keep the points system running well. Just my opinion, if you want to run them hard and long, get a modern bike.
73 Triumph T140 Main Ride 70 Bonnie 67 BSA West Coast Hornet
I've tried one in the past, I did like it because it cured a low speed miss. However, I'm a points guy, mostly because if your points crap out in the middle of nowhere, a file and a little effort can get you home, but a fried ei is a fried ei. Sure, in either case you have got to check out the whole system, but when that ei is fried.....it is fried! (read: stranded on the side of the road 100 or so miles out, and too damned stubborn to suffer the indignity of the bike coming home in someones' pickup. Gimme a file!)
Funny thing I noted about these ei fix it posts, they're all like them darn cooking recipes that start out with "Take a CLEAN pan...", except the ei fix it ones start out with, "Take a NEW battery". Well, modern batteries are made from the same crappy materiels the modern points are, and need to be replaced just about as often it seems. So what are you supposed to do, buy a new battery every few months so that the ei will keep working right? Let's see, let's add THAT to the buy it every 3000 mile list of chains, sprockets, tires, more oil.
Heck, I'm sticking with rummaging through the swap meet bins and grabbing old sets of points cheap! I gots a good lil' file and jest found an old Dunlop that still has a little meat.....
Boyer's old tuning leaflet advised users of late type twin points with nylon heels(if they couldn't run to the new EI), to use Tufnol rubbing heels from earlier points sets. That way a set of points could last a race. To use the entire early points set wasn't so good, because of the lack of independent timing adjustment for respective cylinders.
A good DIY bodger could make a rubbing heel from some wonderful hard-wearing compound and rivet it to a new set of points.
Using a multi-meter check the resistance of each pickup coil should be approx 68-70 and then the total resistance across the wires or terminals should be around 140. With the meter still connected, run your finger round the coils, if the resistance changes there could be a broken wire inside the winding, Rotor magnets should be the same strenth also each magnet should be strong enough to take the rotors own weight hanging from steel bench, To check main box take plugs out reconnect ht leads earth plugs to frame disconnect the two wires at stator plate then with ignition on flash the wires that go to box together if box is ok plugs will spark also you will hear them.