[MrAwesome]

I posted this on the britbike board too, figured maybe one of you could help.

Howdy all, I've got a 71 bonneville I installed a tri-spark classic twin ignition with their dual 6v coils, and their 3-phase alternator/voltage regulator kit. Spendy but the way I wanted to go.

I finally got around to putting this bike back together, and it ran fine before when it ran. So now I've got everything wired up the right way, double checked the diagrams they gave me for the new setup, and went through the static timing procedure. Verified TDC and 38 deg. before with the crankshaft notches, and also through the spark plug hole.

It started up on the first kick, and I didn't even have to kick it very hard, but the bike only ran for a few seconds before I blew a fuse(looks like the original Lucas fuse). The motor sounded great those two seconds as well. I'm thinking I have a short somewhere but I'm not sure how to go about finding it, electrics are not my specialty at all. I've got some new fuses, 15A and 20A, but don't want to try starting again until I'm pretty sure I won't damage the new ignition. I'm hoping the symptoms might be telling of a problem.

Here's some pictures of the wiring...The three alternator wires go to any of the three yellow wires of the voltage regulator, and the black and red wires from the voltage regulator go to their respective battery terminals, those are the extra wires on the terminals.

The jumper wire I have between the coils is brown and white, I just scavenged that from some spare wires I had. It's not connected to anything else. There's also a red wire connecting the white/black and yellow/black, again, just what I had on hand.

The only wires that aren't connected are two blue/brown wires with a single connector, a blue brown wire with a single connector, and two red wires with a single connector, hopefully you can see this.

As it is, it will run for maybe five seconds with a fuse in before it blows. I even took the seat off in case it was shorting out to the pan, and it did the same thing again. I have 15A and 20A fuses.

Any help would be greatly appreciated, I really want to ride this thing again before I have to put it away for winter.

And here's a link to the tri-spark website for their installation instructions and troubleshooting guide. http://www.trispark.com.au/home/installation/

 

[Tony the torch]

disconnect the charging system wires (yellow) and see if the bike will run and not blow a fuse on the battery power only, I suspect it will,and that would make the suspicious fuse blowing part in the charging system.
the bike should have a 25 amp fuse in it too. I know it's scary when you have a $325 ignition in there, and be careful, the Trispark ignitions are kinda voltage sensitive.

 

[MrAwesome]

disconnect the charging system wires (yellow) and see if the bike will run and not blow a fuse on the battery power only, I suspect it will,and that would make the suspicious fuse blowing part in the charging system.
the bike should have a 25 amp fuse in it too. I know it's scary when you have a $325 ignition in there, and be careful, the Trispark ignitions are kinda voltage sensitive.

Tony, I just unplugged the alternator wires. Started it up and you were right, it runs and doesn't blow fuses. And yeah, I'm trying to proceed with caution because I don't want to wreck the thing. So what does this mean for me now?

 

[Tony the torch]

ok make sure you have the charge wires hooked up to the battery correctly, I know this sounds dumb but red is positive and back is negative... right?
then the thing to do is with the black and red wires disconnected from the wiring system, fire up the bike and measure the voltage on across those red and black wire. I should be 12.5 -14.5 VDC, if it's more that that then the regulator box is defective

 

[MrAwesome]

ok make sure you have the charge wires hooked up to the battery correctly, I know this sounds dumb but red is positive and back is negative... right?
then the thing to do is with the black and red wires disconnected from the wiring system, fire up the bike and measure the voltage on across those red and black wire. I should be 12.5 -14.5 VDC, if it's more that that then the regulator box is defective

Yep, red is +, black -. I'll have to check that tomorrow, pretty sure the neighbors will be calling the fuzz if I keep dicking around with the bike tonight. So I should plug the alt wires back into the regulator, disconnect the wires from the reg to the battery, and then measure the output voltage of the two wires while running?

And I can't seem to get the bike to idle below 2,000rpm, even after turning the amal's throttle screws out until they stopped moving the slide down. This will affect the reading I get from the regulator because I'm not reading at idle, right?

 

[MrAwesome]

That idle's probably due to warped carb flanges I bet, I do have a pair of the JRC carbs I was meaning to put on anyway, I'll try that and check the amals just to make sure that's what's going on with the high idle.

 

[flypa38]

If you're still running AMALS, verify that the slide is closing all the way. Whether it is a cable issue, crud in the carb body causing it to stick, or a warped body, if it doesn't close all the way it will "idle"way high like that. Do you have the choke installed? If not make sure where the choke cable used to go is sealed well. Check for intake leaks by spraying carb cleaner around the mating surface of the carb to manifold and the manifold to head joints. Be careful not to spray into the carb intake because it will mislead you. If rpm changes during the spray test you have an intake leak. Hope I'm not being too basic here.....

 

[Mr.Pete]

Having your location listed as "Earth" could complicate the fuse issue.A 17.5 A fuse,at the U.S. rating,will supply 17.5 Amps indefinitely,and a lot more than that for a short time.
It's equivalent to the original British 35 A fuse,which will blow instantly at 35 Amps (British fuse rating).

Your 15A or 20A fuses could be about right.

 

[Tony the torch]

on a later model Triumph with turn signals and a 65 watt headlight if you add things up ..
65 watt Halogen head light = 5.5 amps
35/50 watt tail and brake light = 7.0 amps
(2) 4 ohm coils =6 amps
other small draws like dash lights and electronic ignition = typically around 1.8 amps

it's up over 20 amps now, hit the turn signals and there goes your 20 amp fuse.

The electrical rule I use because of the voltage variation and the resulting amperage fluctuation is the fuse protection should be about 1.5 times the expected maximum load load.
a 10 amp working load is protected well with a 15 amp fuse, and any shorts will blow quickly.