View Full Version : Wits end and feeling stuiped becouse of a Triumph

04-13-2012, 5:53 PM
It's my first build and I 'm proud of it but its going to be pushed off the bench soon. It's a 71 650 single carb motor. It has points, Sparx reg/ rec, with a 12v battery wired in to run the head and taillights.

It ran fine up to a month ago. Took it out for a ride made it down the street and it died. Battery was dead and a 20-amp fuse was blown. Charged the battery and replaced the fuse, kicked the bike a few times and nothing. Fuse was blown and the next battery was dead again.

Replaced the battery, fuse and turned the ignition on all good. Turned the head light on and fuse pops. I went over all the wiring in the bucket checking connector's etc. Found some things loose and fixed.
Back to the begining, new fuse good battery, key on good, headlight and tail/ break light working. Bike still won't turn over. Replaced the spark plugs, checked the wiring again and can fing no breaks.

This leaves the stator, regulator, coils and condensers. How do you know if they're bad if the bike won't run? Could I have blown one or all of these? If testing is replaceing with new, is one more likely to go before the others?

Any thoughts would be helpful... also postes on JJ

04-13-2012, 6:58 PM
Run down to Autozone or Harbor Freight or whatever and pick up a cheap multimeter. You can get one for $10-15 and without it, all you can do is guess and throw new parts on.

To test coils, check for resistance across the primary windings and secondary windings.

With fuses, you need to pull each fuse out and check the resistance across it. Don't trust your eyes. I JUST dealt with this last week. Fuse looked good, but it was partially blown in the plastic portion.

I gotta run, but I'll check back later.

04-14-2012, 2:05 PM
you don't even need a stator or a rotor to run an engine, you can run a engine off of a battery only.
so you running problem is not in the charging system.
check you coils and see if the "hot" wire is hot.

04-14-2012, 8:34 PM
you don't even need a stator or a rotor to run an engine, you can run a engine off of a battery only.
so you running problem is not in the charging system.
check you coils and see if the "hot" wire is hot.

Unless something in the charging system is totally FUBAR, and has a nasty short. That would actually explain the battery and fuses blowing.

04-14-2012, 10:55 PM
then make it easy,... cut the wire from the Sparx charge box and fire it up.
The solid state charge boxes fail sometimes but they seldom dead short to ground.

you have two separate points, coils, and condensers, a points system is tough as hell and the odds of both of them being blown are slim,

pull the plugs out and hold them down on the head and kick it over, see if you have spark or not before you go tearing into everything. you might have a carb problem and not an ignition problem.

04-15-2012, 3:48 PM
Thanks to everyone for the help!
Did some checking with a meter... resistance across the primary and secondary windings on one coil, left side nothing. AC out put on the stator with a strong kick,. Found two more wire shielding cracks on the coil jumper underneath the gas tank. Not sure how to test condensers, but no resistance from tab on top of can to the threaded post.
No spark on ether side (plug held to head and kicking) if the left coil is bad will that keep the right side from sparking?
Mike MRB

04-15-2012, 7:07 PM
one coil failure will not effect the other coil on on a points system , they are completely separate components .
so that goes back to these questions...
1. are you sure you have a points ignition and not an electronic ignition? the coils do effect each other on an E/I.
2. and if you have a points system did you ever check to see if you are getting power to the coils?

04-15-2012, 8:37 PM
Hello Tony,
Its a 71 motor with points. I didn't check to see if there is power from the ignition switch to the coils,duh. I assumed there was because when i turned the key i had power to the headlight. Out to do it right now!


04-15-2012, 9:00 PM
Heres what i know
1 Battery alone 12.3 volts
2 (pos ground) Battery to switch 12.9
3 Switch to RH and LH coil 11.5 volts
4. coils alone RH (ing and jumper off) pos & neg continuity. LH no continuity
So yes power is going to the coils , But the LH coil is dead or "open right?

04-15-2012, 9:26 PM
forget about continuity and ohms and even the actual voltage measurement....the volt meter sometimes does more harm than good, all you really need is a simple 12VDC test light to tell if you are getting power or not. and you need to disconnect the wire that goes down to the points, if that set of points is closed ( and one set is always closed) it will not appear to have power because the power is going through the coil to ground.

So here is what you can do to check to see if the secondary side of the coil is working, open each set of points and put a piece of thick paper in between the points.
take each plug out of the head and connect it to the plug wire, lay it on the head, turn the key on and check each coil on BOTH the + and - terminals, you should have power on both sides of each coil.
Then take a piece of wire and hold it on any good ground point and swipe the other end on the points wire connection at the set of points, every time you do that you should see the spark plug spark, if it doesn't spark then that coil or the wire going to it is bad or maybe the plug is bad.
switch plugs then wires and coils around until you find the bad component.

the two most used tools I have at the shop is a set of those spark plug testers and a 12 volt test light.

04-15-2012, 9:43 PM
On it first thing in the morning

04-16-2012, 10:59 AM
Following Tony's instructions
Test light good on RH coil Not on LH. Pulled the plugs and opened the the points cover. Put paper between both open points and tested. Power to the RH none on LH wire. Check the LH wire from point to coil continuity was good and no signs of breaks.
Using Tony's method RH plug sparked none on the LH


04-16-2012, 5:47 PM
Left coil only .....(and fuck continuity, a shorted out wire or condensor will always give you a continuity reading)
Here's what you do...

if are you saying that nether one of the terminals on the left coil is showing hot? ( With a test light) then it's a bad hot wire going to that coil no mater how good that wire looks.
(with the wire going down to the points and condensor disconnected at the coil)... if one terminal shows hot but the other one doesn't show up as hot then it's a bad coil,

if you connect the wire going down to the points on the coil back up with the paper in the points and it isn't hot then the wire or condenser is shorted to ground.
with the paper in between the points both the + and the - terminal on each coil should show as hot...