Classic Triumph Bonneville

[Rockburner]

Time for an oil change. The oil which is in there is the stuff which went in following the full rebuild ~200 miles ago.

I don't actually know how far ago it was cause the odometer is buggered . I know I rode it to work (90 mile round trip) and a did a couple of short shakedowns and the like.

It needs "old" type oil because the clearances and galleries are all relatively massive, it doesn't have a filter and it relies on oil being flung about and sticking to things way more than a modern engine. Lubrication is much more "targeted" in something newer. Not having the filter is the biggy, modern oil is designed to keep crap in suspension until its filtered out, exactly what you don't want on this bike. On this bike you want the gumpf to fall out of the oil and stay in the sludge traps.

Weirdly Halfords don't seem to sell Castrol Classic any more. They sell their own stuff but not the good old green cans. From what I can see Castrol has a higher percentage of all the nasty heavy metal goodies my old engine likes...but I can't use my trade card to buy it

Oh well! Castrol shop on amazon it is!

Take a look at feked.com, i bought Miller R30 and R40 from them for reasonable prices.

30 for spring/autumn. 40 for summer. At least until i figure out what the JAPton seems to like.

[Mr. Dazzle]

A gallon of Castrol XL20/50 was £35 on Amazon (on Castrol's official shop), which is the cheapest I found anywhere.

You can tell it's for classics, 'cause it comes in gallons

[Mr. Dazzle]

I was planning on going to Cassington bike night on Monday but the bike had other ideas.

The last few times I've ridden her she's been pretty faultless, I did >100 miles on my last outing a few weeks ago. Single kick starts etc.

Not on Monday...hard to start and won't idle. The latter of those is pretty normal when cold TBF - got no chokes! However I only made it to the end of my street and for reasons not relevant I didn't have time to investigate further.

Had a look at lunchtime but won't start at all now. Got a couple of coughs and bangs so clearly fuel and sparks are nearly there. The battery was quite flat but I was getting sparks. Nominally the battery doesn't matter, but the boyer black box which replaced the points pokes a hole in that theory. They like a nice healthy battery, so I whipped it out and put it on charge.

Just been out there and I've now got 13.2V but no sparks at all! Plenty of fuel but no sparks.

Hmmmmmm....

[A_morti]

You've way more patience than I.

[KungFooBob]

It's been a long time since I had a Boyer box on my two-stoke race bike, but they do go wrong. However Boyer Support used to be brilliant (15 years ago), worth giving them a call, they'll know what/how to check that its not the Boyer Box at fault, they might even replace it as a gesture of good will if it is at fault (they did for me and I had no proof of purchase as it came with the bike unfitted).

[Mr. Dazzle]

Their website is pretty comprehensive TBF.

I think of the Boyer box as the modern reliable bit, but it's probably older than I am.

Gonna rule out obvious things like loose wires and buggered switches first.

[KungFooBob]

Their website is pretty comprehensive TBF.

I think of the Boyer box as the modern reliable bit, but it's probably older than I am.

Something in my head says the road bike ones used to 'burn out' if you left the ignition on for an extended period without the engine running.

[Mr. Dazzle]

I remember doing loads of checks ages ago with a multimeter and turning the ignition on/off....should get 12v here and 12v there....just can't remember what they were

[Mr. Dazzle]

You've way more patience than I.

I'm totally a buying brand spanking new electric Speed Triple thing when they're available.

Probably won't work either

[Rockburner]

Their website is pretty comprehensive TBF.

I think of the Boyer box as the modern reliable bit, but it's probably older than I am.

Gonna rule out obvious things like loose wires and buggered switches first.

It's possible/probable that its just a loose earth.

[JackyJoll]

Their website is pretty comprehensive TBF.

I think of the Boyer box as the modern reliable bit, but it's probably older than I am.

Gonna rule out obvious things like loose wires and buggered switches first.

It's possible/probable that its just a loose earth.

Electronic ignition conversions on old bikes really love very solid conduction paths, live and return.

Don’t rely on the bike frame or engine casings for return. Always suspect the ignition switch and all connections on tbe live side. Don’t have a kill switch interrupting the live feed.

[Mr. Dazzle]

S'got direct wiring for the box....it didn't have when I first got the bike, but it does now!

However, come to think of it, I did take the battery out to charge it and my mysterious problem came to head then. So maybe iffy connections is a good shout.

[Le_Fromage_Grande]

First rule of fault finding - what might I have broken.

[mangocrazy]

I refer Sir to Sir's own fault-fnding logic:

Dodgy_earth.PNG (4.35 KiB) Viewed 542 times

[David]

For a replacement clever box try MiniMag on tje I.O.W.
Julian who makes the stuff is very knowledgeable and helpful.

[Mr. Dazzle]

Had a poke about this morning.

Confirmed that no, I still don't have sparks. So I offs with the tank a start 'avin a look. Confirmed nice solid earth path from the box and indeed anywhere else. 13V all day long all over the place. Battery terminals were a tiny smidge loose (they're just push fit) so I tightened them up.

Coils pass all their resistance checks. Get the right amount of voltage when you turn the ignition on. Fooled me for a min, because I forgot the box only sends juice for a couple of seconds rather than just staying on (saves it burning out the coils IIRC). Normally when the engine's running the coils are only "on" for about half the time.

So then it's on to the Boyer troubleshooting guide.

First thing is check that, with the ignition on, touching the white/black and yellow/black wires together makes it spark....which they do. Next is check the same two wires, from 'other side' read 138ohm...which they do.



This is just checking the stator, the bit which actually tells the box when to fire the plugs, is still intact and that the box correctly acts on the stator's commands.

The next bit would have been to open up the timing cover and check the rotors are still actually magnetic. It seems pretty unlikely that wouldn't be the case and opening the cover means removing the exhausts on this bike it's the small round cover at the bottom of the pic behind the header


So on a whim I just cleaned up the wires I'd disconnect and tried her again. Kicking over now generates lovely fat sparks

I can only assume it was loose connections in the boyer wiring?

Anywhoo....I had to unwrap about 5 mile of circa 1987 Halfords electrical tape to get this far. The prospect of putting that back together fills me with deep joy.

[Le_Fromage_Grande]

Assuming it works like any other electronic ignition, you should get a constant 12V at one wire of the coils, the ignition system puts an earth on other wire when it's time to fire

[Mr. Dazzle]

Assuming it works like any other electronic lgniton

It doesn't, not quite anyway. Nearly

It's two 6V coils in series...so you put 12V across the pair, but cause they're in series each only sees 6V. Even then it only puts that 12V (or 6!) for a few seconds when you turn the key, to save having the coils sat there energised.

Normally when the engine's running that 12V supply is on all the time, but the coils are only seeing it some of the time, cause the ignition system cuts the supply periodically to make the sparks. If you just left the 12V on all the time the coils would get hotter and hotter.

The "few seconds" thing must surely be a Boyer feature cause I don't see how the OE Triumph mechancial system could achieve that. OE ones probably do just fry their coils if you turn the key but don't start the engine!

The white and yellow wires go down to the stator, which is next to the rotor on the crank. The stator generates a little electrical pulse whcih tells the black box to cut power to the coils and hence generate a spark, tapping the two terminals together achieves the same thing.

[crust]

Rather than use sticky electrical tape why not use this:

https://hilltop-products.co.uk/ldpe-spi ... _g_c_pla__

[JackyJoll]

You’ll always have problems while you’re depending on those pre-insulated terminals half-squashed onto the wires.