77 bonnie ignition mess. Where to start?

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Skriski

Member
I've recently obtained a 1977 T140 that the previous owners had a "friend" build. has not been started since '05 and then it was "only once" is the story I get. It is nearly stock.... except for the ignition and most wiring. There is no ignition switch, just an "on-off' switch on the headlamp. Also.. running a battery-less system. Its been converted to a Boyer with a Mity max battery replacement. The coil(s) it seems is also a replacement, being unlike what is shown in the manual, and looking like something I can buy online.. its a smaller rectangular pack with both plug wires connecting to the one pack. (about 3x4in?) Ive just put the motor back together and was seeing what kind of spark the machine was putting out and... well.. little to none. Sometimes I get a spark, but then its gone for the next 10 or so kicks.. maybe coming back, maybe not. Usually sparks early in my trial. Anyway.. wanting to know how to go back to a battery system and dont really know where to start (aside from stripping one out of another bike). I would just remove the Mity Max, but the manual shows a 3 lead alternator, and this only has 2 leads coming from the (assumably) upgraded alt. so I dont know how to wire it up for a battery, that is with the upgraded ignition. Would I still need to rectify? Would I still need the Zener Diode voltage regulator? (neither of these can I currently locate on the bike). Would I need to go back to a 3 lead alt? Any help? Thank you VERY much.

Skriski
 
I agree with Rocky. If it it were my bike, I would go back to stock with a stock wiring harness. I would add an electronic ignition with battery, GrandPaul is the one to help you with this.
 
Could be a weak capacitor circuit in the Mity Max. The intermittent spark could also indicate a loose ignition rotor that is only spinning part of the time.

Check the rotor, then clip a battery charger to exposed connectors at the Mity Max (CAREFUL WITH POLARITY)

Give it a few seconds to tricle charge, then try a kick and see what you get.
 
CarlS said:
I agree with Rocky. If it it were my bike, I would go back to stock with a stock wiring harness. I would add an electronic ignition with battery, GrandPaul is the one to help you with this.
Click to expand...
That's what I had in the back of my mind; get a new wiring harness, ignition switch, a new battery and start from there.
You already have the Boyer.
 
Best thing is to photograph each electrical part so we can definitely i.d. them. Then, we can determine the simplest wiring to produce a complete working ignition and regulated/rectified power source.
 
Thanks for all of the (quick) relpies!! GrandPaul, I had thought of those... and had actually checked the rotor(all good), and did in fact attempt to hook up my battery charger to the system, just wasnt sure where to place the leads.. There are 4 wires from the Mity Max... two come FROM the alternator (they are green) and 2 Reds, one going to ground, and one going to the connector block with a Fused link.. I assumed these were where a normal battery would be in the circuit, so I put the positive to the Fused line, and the negative to ground... I didnt let it "charge " at all, but I guess I figured it would have been just like having a battery installed. If this configuration seems right, then I will go ahead and give it a go after it trickles a bit, but if I should be hooking the leads to the greens... then please let me know.. Thanks again, and I will post some pics of the mess I have if I dont get anywhere with this procedure....
 
OK, so heres the update... I hooked up my batt charger as we spoke of, gave it a few moments and noticed that the charger kept kicking off, then on... (no previous issues with charger, so I assume its something to do with the system.. I was getting HEAT at the charger leads pretty quickly.) aaaanywayyy.. gave it a few kicks and no real change.. still sparks intermittent but did notice that when it DOES spark.. I also had considerable arcing at the charger leads where I had them connected to the positive bike lead.. (dont know if that means anything). I decided to look through the numerous parts that came with the bike (in a big rotting tin) and found everything from the stock system.. coils, tympanium unit, old alternator (with 2 leads mind you) rectifier (have yet to locate the diode).. and a few things that I didnt know what they were.. ALLL beside the point (aside from the tympanium unit) as I found THIS while searching online (pretty much what im looking for .. I think).

http://raskcycle.com/techtip/webdoc16a.html

Only questions I have are.....
1.)manual shows original system was 12v..should I assume that the system I am looking to go with is also 12v, I have read some things that may point to a 6v system?
2.) Positive or negative Ground? (does it matter?) and finally...
3.) Im looking online, but maybe someone here can tell me... How do I check to see if the Tympanium unit I have is good or needs replacing?

I know how to check the coils(not planning on using the old ones) and I think Ive seen how to check Boyer unit.

That is all..............Thanks for your support!!! Loving this Forum BTW.
 
The ground certainly does matter - big time. I do not know what year Triumph switched to negative ground. I have never owned and older Triumph newer than 1971. All the ones I owned/own have positive ground. By what you described above, it sounds like yours is positive ground.
 
Sounds like you had positive and negative leads swapped on the charger (they SHOULD NOT get hot at any time).

'77 SHOULD be POSITIVE ground, but could easily be swapped with no way of knowing without carefully tracing each wire (I'd start with the rectifier output ground)
 
Thanks guys, manual does call for positive ground, and I did hook red to pos black to neg, but the wiring is not original so...... Any way, NEW UPDATE!. hooked the charger to the alt. stator leads and WALLA! full consistant spark! It was a relief. Checked the stator ohms and they read the required 9. Going to rewire the whole bike this weekend with a battery, and the tympanium unit. Going to use the positive ground schematic and hope for the best! Hoping then I can check the alt output and be on my way. Wish me luck and thanks for all the input!!!
 
Skriski said:
Thanks guys, manual does call for positive ground, and I did hook red to pos black to neg, but the wiring is not original so...... Any way, NEW UPDATE!. hooked the charger to the alt. stator leads and WALLA! full consistant spark! It was a relief. Checked the stator ohms and they read the required 9. Going to rewire the whole bike this weekend with a battery, and the tympanium unit. Going to use the positive ground schematic and hope for the best! Hoping then I can check the alt output and be on my way. Wish me luck and thanks for all the input!!!
Click to expand...

Thanks for the update. Good decision to use the positive ground. Please keep us posted on your progress.
 
Latest update.... wiring the bike was much MUCH faster than I anticipated... and the old rectifying unit is apparently GOOD since upon the rewire, and battery installation, SPARK IS AMAZING.. Hope to get the bike fired up this weekend and hoping I wont have any trouble with a "frozen clutch syndrom". Bike has sat for a long time, but everything inside the motor for as far as I dismantled it looked great. I did NOT delve into the state of the clutch, but DO remember it not releasing the tranny then I pulled the clutch lever (upon initial inspection of cycle before purchase). Ill probably look into it a bit before trying to start the bike, see if I can get it to disengage. (hoping for just an adjustment) Havent mussed with it yet.
 
Skriski said:
Latest update.... wiring the bike was much MUCH faster than I anticipated... and the old rectifying unit is apparently GOOD since upon the rewire, and battery installation, SPARK IS AMAZING.. Hope to get the bike fired up this weekend and hoping I wont have any trouble with a "frozen clutch syndrom". Bike has sat for a long time, but everything inside the motor for as far as I dismantled it looked great. I did NOT delve into the state of the clutch, but DO remember it not releasing the tranny then I pulled the clutch lever (upon initial inspection of cycle before purchase). Ill probably look into it a bit before trying to start the bike, see if I can get it to disengage. (hoping for just an adjustment) Havent mussed with it yet.
Click to expand...

That is GREAT news. TUP

Regarding the clutch. With these bikes, you have to pull in the clutch with the bike in neutral and, with the ignition off, crank the bike until the clutch is free. I do this even if the bike has only been shut down for a short time before I crank it. If you don't, you can have an unexpected surprise when the bike starts. I know. :y2:
 

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