[Stockton350]

Hi folks,

I picked up a 1972 Triumph this week and am hoping to fix it up and ride it this fall. I've brought a bunch of old Japanese bikes back from the dead but this is my first British bike and I have some basic questions for anyone who can spare a minute:

First, I'm trying to get spark. Does this bike need a battery to produce a spark?

For other projects, I've run 12v directly to the coils to test for spark. This wiring configuration seems to run positive to the frame. Is that correct? Which coil wire can I run 12v to to power the coils?

I'm able to open the oil cap on the top of the frame but there is no dipstick attached to the cap. How does one check the oil?

Sorry for the dumb questions. This is my first British bike and the set up is different from the UJMs I've worked on so apologies for my ignorance.

 

[Flicker]

so apologies for my ignorance.

No apologies required and welcome to CVV
I've got a nearly identical bike, mine with a single carb
Positive common, so your hot wires will be -12vdc, red goes to frame and plus battery terminal.
Just fill oil until you can see it come up to a couple inches from filler opening
I would not run the throttle and choke cables through the grommet at the steering head
Speedo cable mounted wrong too. It should come down the frame and under and then loosely to swingarm.
Looks like you have a "High Frame". Frame changed mid 72, sloping the seat down at front as well as different center stand mount.
Same ground clearance, different seat height.
Lots of really smart people here willing to help you and rebuild threads for very similar bikes.
White wire is essential hot - ignition, brake lights
White goes to kill switch on handlebar and comes out as white-yellow which is ignition.
I would get a good battery for it, but it can start without one if everything's perfect.
Get the workshop manual and replacement parts catalog, they're very good.
- Mark

 

[StuartMac]

Hi,

welcome to CVV

+1.

Just fill oil until you can see it come up to a couple inches from filler opening

Mmmm ... imho, depends how long the bike's stood unused. If more than about three months, I follow the advice in Waking The Sleeping Beast; reasons are:-

. There are several splash-lubricated bearings in the crankcase - no oil on them when the engine starts, they'll be spinning and rubbing against each other at a few thousand rpm for a relatively-long time 'til oil's pumped from the frame through the crank and big-end bearings to fall into the crankcase. Otoh, lubed with a squirt-can and some oil in the crankcase, the bearings will have oil on/in 'em even before the engine starts.

. When you start an unknown engine for the first time, you don't have any idea what the oil pump's doing. You should be watching the frame filler hole for returning oil but, no oil in the crankcase, you don't know if you're just waiting for pumped oil to return ... or there's something wrong with the pump ... Otoh, some oil in the crankcase, pump working, you can expect the oil to reappear in the frame filler hole PDQ after the engine starts.

If you follow the WTSB advice, don't put quite so much oil in the crankcase - WTSB was written for triples, they have a larger crankcase volume.

Get the workshop manual and replacement parts catalog, they're very good.

+1. Available free-to-read on line - Triumph '71/'72 650 workshop manual, Triumph '72 650 replacement parts catalog.

Hth.

Regards,

 

[Stockton350]

Thank you Flicker and StuartMac. Much appreciated. The common positive is a new one for me so glad to have that cleared up. I'll also be sure to pre lubricate the engine before I try to fire it up.

The good news is that I was able to get spark on both sides. I can get spark on the left with the kick start lever. On the right, I'm only getting it when I bridge the points with a screw driver. The points don't appear to be opening and closing completely and I suspect the missing screw isn't helping retain the proper gap. See picture. Are the fasteners on these bikes metric? Any chance you know what size this screw would be?

Also, I'm attaching a photo of the frame with the oil cap off. I see zero oil. My understanding is that I need to fill up to 2" from the top and then follow the Sleeping Beast article about applying oil to the valves. Does that sound right?

I'm having a manual and the parts catalog printed tomorrow when the copy center opens up again, so hopefully I won't need to pester folks here. Thank you!

 

[Stockton350]

Follow up. Looks like that missing part isn't a bolt but rather an adjustment pin (#22). Is that correct?

 

[Flicker]

Follow up. Looks like that missing part isn't a bolt but rather an adjustment pin (#22). Is that correct?

Yes.
People here kind of get a kick out of being "pestered" in my estimation because they love these old heaps and want to help, so don't worry about that.
As far as parts go, they are widely available (in no particular order, they all have their strengths)

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and more! A phone call to them will save you time in most situations as they are all experts.
Also, there are several shops in the UK that have very good deals and the shipping here is cheap and fast.
Happy wrenching

 

[Rancidpegwoman]

Are the fasteners on these bikes metric?

Hi,
By ‘72 most of the threads had changes to American UNF/UNC, but Triumph still retained a few British threads just to catch you out every now and then😊
I don’t think there are any standard Metric threads on a ‘72 , bit a previous owner might have put some on (less likely in the USA than some other parts of the world)

 

[Rancidpegwoman]

Lucas Essentric Points Adjusting Screws (2) - 54419220 - 1968-78

*Just Arrived!* NOS Genuine Lucas Essentric Contact Breaker Points Adjuster Screws. These Lucas Screws are very "Hard To Find"! Which is Exactly why we have started to source these! Works with most Triumph, BSA, Royal Enfield & Norton Motorcycles including Twins & Triples from approx 1968-1978...

www.classicbritishspares.com

 

[StuartMac]

Hi,

spark
On the right
suspect the missing screw isn't helping retain the proper gap.
size this screw would be?

4BA ...

Are the fasteners on these bikes metric?

Can Of Worms Alert!

Short answer to your question - no, never.

Longer answer, firstly, digressing slightly from your points screw thread question:-

. By-and-large ... fasteners with a shank diameter 1/4" or larger have Unified threads. Tools that fit these fasteners are marked with the hex. AF (Across Flats); e.g. 1/4" bolt or nut is 7/16" AF (similar to a M6 bolt or nut is 10 mm. AF).

. However, there are a few British Standard fasteners left in to keep you on your toes - off the top of my head, I remember the bolts that secure the cylinder head to the block are 3/8"-26 = British Standard Cycle aka Cycle Engineers Institute (CEI). Tools that fit these are marked with their shank diameter (aka "major diameter"); e.g. head bolts will require a socket marked "3/8 BS". Many of your countrymen will confuse you further by referring to such fasteners and tools as "Whitworth" ...

Returning to your points screw thread question:-

. Fasteners with a shank diameter less than 1/4" are generally BA = "British Association" (aside, an abbreviation of British Association for the Advancement of Science). BA diameters and pitches are rarely either exact inch or metric fractions so each size is simply a number suffixed by "BA", e.g. the 4BA-thread points screws - the bigger the BA number, the smaller the fastener.

. However, note "are generally BA" ... some are Unified-thread ... which can be similar to BA around the same diameter but aren't ever interchangeable - if you find a small screw doesn't fit, never assume it's just an iffy thread and, if you apply a leeetle more force ... 'Til you're clear on individual differences, maybe always post the question first?

View attachment 796844
see zero oil. My understanding is that I need to fill up to 2" from the top and then follow the Sleeping Beast article about applying oil to the valves. Does that sound right?

'Fraid wrong ...

All old engine oil drained out of both frame and engine, the Waking The Sleeping Beast advice includes putting some engine oil in the crankcase. When the engine starts, that oil will (should) be pumped from the crankcase into the frame. That's how the oiling system works - one part of the pump sucks oil from the frame and pumps it into the engine, that oil drains to the bottom of the crankcase, the other part of the pump sucks that oil from the crankcase and pumps it back to the frame.

WTSB advises putting two pints of oil in the crankcase. As I posted previously, that's in a triple which has a larger crankcase than your twin, and it's British pints; your bike, imho about 1.5 US pints.

BUT (and it's a J-Lo) ...

When you get your workshop manual, you'll see your bike's engine (frame) oil capacity is 4 British pints = 4.8 US pints.

So, were you to follow @Flicker Mark's advice - "fill up to 2" from the top" - and follow the WTSB/my advice, about 1.5 US pints out of the crankcase is going to go a lot further up the frame tube than 2" ...

Imho: about 1.5 US pints into the crankcase and about 2.5 US pints in the frame; intentionally, that totals a little less than the complete 4.8 US pints but is more than enough for the engine to circulate once it starts; only after a quick test run 'round the block - and if you then don't intend to strip the engine - is it worth checking the oil level in the frame (which should then be around 4 US pints) and top-up if necessary.

coming from the multiverse of Japanese bikes.

Be aware, apart from the frame, these old heaps have three separate compartments in the engine that can or should contain oil, one of which - the gearbox - takes oil that isn't 20w50 or 15w50 engine oil ...

When you get your workshop manual, note the drawing on page A7 (Section A, page 7) identifies various hex.-heads under the engine:-

1. is the primary chaincase drain.

3. is the gearbox drain; if you drain this, refill with EP90 gearbox oil.

4. is the crankcase drain.

. Not just this time but always in the future, before undoing a drain bolt, ensure the area around it is clean - free from oil, mud, grit, etc. - and degrease the drain bolt before refitting it.

. WTSB advises getting the oil into the crankcase through the primary chaincase filler - the two compartments are connected on triples and on '70-on twins. Most of the oil you put in the primary will drain into the crankcase; when the engine starts, that'll be splashed around and then pumped out into the frame; however, a small amount intentionally will remain in the primary to lubricate the chain and clutch rollers.

Hth.

Regards,

 

[Stockton350]

Thanks, everyone. Non metric will be another adjustment coming from the multiverse of Japanese bikes. Stuart, I'll follow your advice about 1.5 pints in the crank case and 2.5 into the frame after draining completely.

This bike came my way from an old timer in New Hampshire who had the bike registered in 2008 but has since passed. There's some rather interesting electrical work that has been done which leads me to speculate that he was not an electrical engineer and I think it might be causing an issue with the right spark. Attached is a photo of what the wiring currently looks like.

New item by B.A. Myint

photos.app.goo.gl

I'm referencing a writing diagram here.

https://www.triumphrat.net/attachments/1972-wiring-diagram-pdf.486074/

Am I interpreting the coil wiring correctly? What color are the contract breaker wires?

Left coil
4 wires
Negative terminal #1 y/w (12v with key on)
Negative terminal #2 y/w to negative terminal of right coil
Positive terminal #1 b/w to capacitor
Positive terminal #2 ?? To contact breaker

Right coil
3 wires
Negative terminal #1 y/w from negative terminal of left coil
Positive terminal #1 b/w to capacitor
Positive terminal #2 ?? To contact breaker

 

[Flicker]

What color are the contract breaker wires?

Stockton,
Black/White and Black/Yellow
Same to each condenser (capacitor) in parallel with each breaker

 

[Stockton350]

Thanks. Is this the condenser by the way?

New item by B.A. Myint

photos.app.goo.gl

 

[StuartMac]

Hi,

New item by B.A. Myint

photos.app.goo.gl

condenser by the way?

Sort-of. Wires' female spade terminals pulled off the the male spade terminals, the black rubber cover you can see could originally be slid off over the male spade terminals, revealing the two actual condensers (one for each contact-breaker).

Am I interpreting the coil wiring correctly?

Referring to your photo. above:-

. The coil on the right of the photo. (left coil on the bike) has two White/Yellow (insulation mainly White with thin Yellow tracer lines) wires into the same female spade terminal on the coil's "-" (negative) terminal:-

.. one White/Yellow is (should be) from the handlebar kill button (one of the four black push-buttons);

.. the other White/Yellow goes to the "-" terminal on the coil on the left of the photo. (right coil on the bike).

. Black/White (insulation mainly Black with thin White tracer lines) wire from the "+" terminal of the coil on the right of the photo. (left coil on the bike) to the female spade terminal on the male spade terminal of the condenser on the right of the photo. (left condenser on the bike).

. There is another Black/White wire from the condenser female spade terminal, this wire goes to the forward/rightmost contact-breaker (usually) in the circular compartment in the engine timing cover.

. Similarly, Black/Yellow wire from the "+" terminal of the coil on the left of the photo. (right coil on the bike) to the female spade terminal on the male spade terminal of the condenser on the left of the photo. (right condenser on the bike) and another Black/Yellow wire from the condenser female spade terminal to the rear/leftmost contact-breaker (usually) in the circular compartment in the engine timing cover.

some rather interesting electrical work that has been done which leads me to speculate that he was not an electrical engineer and I think it might be causing an issue with the right spark.

. The above leaves the (thick White?) wire(s?) with the piss-poor mangled blue-insulated terminals on each coil's "-" terminal. Something added by a PO, no idea what for unless the White/Yelllow wire between the two coils' "-" terminals is broken? To check for this: disconnect the piss-poor mangled blue-insulated terminals from the coils' "-" terminals, set your meter to Ohms (horseshoe-shaped symbol?), put one meter lead end on each coil's "-" terminal, the meter shouldn't display any more than 0.5 Ohm (ideally much less). If yes, remove the wire(s?) with the piss-poor mangled blue-insulated terminals and throw them in your "maybe useful one day" box.

issue with the right spark.

All wiring reconnected (better-insulated wire between the two coils' "-" terminals if the standard White/Yellow wire between them is broken), reset your meter to a Volts scale, turn on the ignition switch:-

1. Measure first just across the battery (one meter lead terminal on each battery terminal) and note the meter reading (12.6V?).

2. Then measure between each coil's "-" terminal and the battery "+" terminal, both these meter readings should be very similar (within 0.1V) of the reading you saw at 1.

3. If yes to 2., measure between each coil's "+" terminal and the battery "-" terminal; again, both these meter readings should be very similar of the reading you saw at 1.

4. If yes to 3., measure between each contact-breaker's wire (Black/White and Black/Yellow) and the battery "-" terminal; once again, both these meter readings should be very similar of the reading you saw at 1.

Btw, note I've added some more information to my previous post #9.

Hth.

Regards,

 

[Stockton350]

Thanks, Stuart. My goodness, the previous owner must have been a butcher because that's what he did to the harness. I think I've tidied up the wiring. I couldn't get the 12v to come back through the kill switch so I opened it the switch to see if the contacts needed cleaning... Inside the switch, turns out the wires weren't connected to anything. They were just taped off under a stub of electrical tape.

While I work on repairing the switch, I have jumped the white wire to the white/yellow, so I can get power to the coils when the key is on. I've got spark on both sides now.

Before I attempt to fire up the engine, I just want to double check on some oil-related questions that still aren't clear after reading the manual:

• The manual describes removing the sump drain plug. My understanding, is that's #4 below. Correct?
• The manual then describes an oil resevoir filter at the bottom of the reservoir fastened by four nuts. Is this step needed in order for me to clear out the old oil?
• @StuartMac - Just a few follow up questions on post #9 above if that's okay:

-

Be aware, apart from the frame, these old heaps have three separate compartments in the engine that can or should contain oil, one of which - the gearbox - takes oil that isn't 20w50 or 15w50 engine oil ...

Can you recommend a decent 20 or 15W50 engine oil that I should be using? For all my Japanese bikes, I've used the same Shell Rotella but want to check first on what to use.
- Should I also be changing the gearbox oil at this point?
-

WTSB advises getting the oil into the crankcase through the primary chaincase filler

Is the filler plug referenced here the notched circle plug on the left top side of the crankcase?


Thanks in advance!



-

 

[Flicker]

Remove the 4 nuts and see if there's gunk inside
A screen rides the plate inside, that'll need cleaning and you'll need a pair of gaskets to sandwich the screen plate
To remove primary and gearbox fill plugs, I use a piece of 1/8 thick steel or aluminum rounded off or a drag link socket
Yes 4 is the sump drain, and primary shares oil with crankcase and will drain in.
Some would say you'd be wise to remove primary cover and have a look-see
Opinions vary wildly (and usually heatedly) on oil, some swearing never use detergent oil because it could loosen sludge in crank trap
I use Lucas 20/50 classic car oil, high zinc. V Twin oil by Lucas is popular too.
I hate electrical tape.
Good luck with your first start!

 

[Stockton350]

Thanks, Mark. I have ordered a couple of gaskets and will remove and clean the filter once those arrive. I guess I won't be firing it up today after all.

I watched a couple of YouTube videos, and saw a couple of guys remove the bolt at the base of the cylinder, and inject oil through that hole. I don't see a reference to this in the manual. Is this necessary if I I'm going to add oil through the slotted crankcase plug hole?

 

[Flicker]

View attachment 797338

Thanks, Mark. I have ordered a couple of gaskets and will remove and clean the filter once those arrive. I guess I won't be firing it up today after all.

I watched a couple of YouTube videos, and saw a couple of guys remove the bolt at the base of the cylinder, and inject oil through that hole. I don't see a reference to this in the manual. Is this necessary if I I'm going to add oil through the slotted crankcase plug hole?

Yep you could oil it through there for sure, even better than overfilling your primary. Good call
It's for a plunger tool to find TDC and 38 deg BTDC
No filter in the frame, just a screen, but the oil pickup is well off the bottom to let any sediment fall

 

[StuartMac]

Hi,

couldn't get the 12v to come back through the kill switch so I opened it the switch to see if the contacts needed cleaning... Inside the switch, turns out the wires weren't connected to anything. They were just taped off under a stub of electrical tape.
View attachment 797278

Assuming it's a standard pre-'76 twin switch cluster, the "kill switch" was one of the push-buttons, the lever was for the turn signals, did the DPO remove 'em?

While I work on repairing the switch

Fwiw, if you or someone you know is reasonably-good at soldering and has the right iron, not too difficult to reattach wires to switch solder points. Might be the best course as, since the long-time pattern switch maker stopped, the prices of both Lucas originals and Sparx patterns have risen considerably.

In case you're wondering, the other button in that cluster - plain White and White/Red wires not shown in wiring diagrams - was for an electric starter ... Unmolested switch cluster, I usually connect the White/Red wire to either main wiring harness Blue/White (headlamp main beam) wires or Purple/Black (horn) wire; because, as standard, both of the latter functions are operated by buttons in the other handlebar switch cluster - White/Red connected, both functions can be operated at the same time if ever necessary...

have jumped the white wire to the white/yellow, so I can get power to the coils when the key is on. I've got spark on both sides now.

manual describes removing the sump drain plug. My understanding, is that's #4 below. Correct?

Correct.

manual then describes an oil resevoir filter at the bottom of the reservoir fastened by four nuts. Is this step needed in order for me to clear out the old oil?

As @Flicker Mark posted,

decent 20 or 15W50 engine oil that I should be using?

Pretty-much as Mark posted, buy the best you can afford - I don't think anyone sensible ever took an engine apart and said, "Hmmm ... could've used cheaper oil" ...

Whichever engine oil you choose, ensure it has "JASO MA2" amongst the specs. listed on the container - ensures it lacks the additives that can cause clutch slip.

detergent oil because it could loosen sludge in crank trap

Regrettably a can of worms, primarily because, before and despite after the www, some people came up with the most God-awful twaddle about particularly engine oil:-

. the oils Triumph recommended at any given time were normal, standard off-the-shelf oils at the time;

. detergent additives have been in engine oil since God was in short pants; it's only the truly-ignorant of this can extrapolate that Triumph somehow recommended non-detergent oils;

. even if such a DPO is in your bike's past, it's still unlikely that using normal, standard off-the-shelf oil now could loosen sludge in crank trap, the crank sludge trap is by definition a centrifugal filter.

Should I also be changing the gearbox oil at this point?

If you don't know for sure what's in there, it'd be wise?

WTSB advises getting the oil into the crankcase through the primary chaincase filler

Is the filler plug referenced here the notched circle plug on the left top side of the crankcase?

Hopefully for clarity, the way I'd describe it is: the primary chaincase is the large oval casting on the left-hand side (looking forwards) of the engine, partially the left-hand crankcase and partially the corresponding large oval cover casting; the filler is the roughly-1"-diameter slotted plug on top of the crankcase part.

watched a couple of YouTube videos, and saw a couple of guys remove the bolt at the base of the cylinder, and inject oil through that hole. I don't see a reference to this in the manual. Is this necessary if I I'm going to add oil through the slotted crankcase plug hole?

No.

As Mark posted, the hole at the base of the cylinder is for the timing position tool; having had to use it on pre-'70 twins (primary sealed off from crankcase), I can say from first-hand experience it's a really crap idea:-

. the timing position tool hole is a much smaller diameter than the intentionally-large primary filler hole;

. the hole's between and below a T120's inlet tracts; OIF, it's also under the large-diameter frame tube;

. the hole's at an angle;

. any twin's flywheel is just underneath it, further restricting the oil quantity that'll fit through the hole at any given time;

. unless you enjoy watching paint dry and similar,

Hth.

Regards,

 

[Flicker]

particularly engine oil:

a long time ago on a different forum I raised an innocent question on recommended oil.
I was bombarded by multiple different, sometimes nasty, diatribes on the subject, the net result being they all canceled each other out and I was no better informed than before I asked.
So thanks for the clarification on detergent oil, @StuartMac.

 

[Stockton350]

Thank you, both.

Assuming it's a standard pre-'76 twin switch cluster, the "kill switch" was one of the push-buttons, the lever was for the turn signals, did the DPO remove 'em?

The switch cluster has a lever in the middle, something that looks like a button on top but does not actually press in, and an intermittent button on the bottom. So the lever is for turn signals and the bottom button is the kiill switch?

Left side handlebar switch (5 wires)
white and yellow/white = 12v
green and green/white = flasher warning light
light green - flasher unit

So on these bikes, the kill switch only intermittently stops the 12v going to the coil? On my previous bikes, there's an on/off switch that sends/cuts off 12v to the coil so they don't get overcharged with the key on and engine off. Does this mean that with the key on the 3 or 4 position, 12v will always be going to the coils?

So pressing the button snould stop continuity between the W and W/Y?

The PO installed an accessory horn switch on the left side handlebar so I'm assuming the button on the right hand switch stopped working and maybe he didn't feel like cleaning the contacts?

Fwiw, if you or someone you know is reasonably-good at soldering and has the right iron, not too difficult to reattach wires to switch solder points. Might be the best course as, since the long-time pattern switch maker stopped, the prices of both Lucas originals and Sparx patterns have risen considerably.

I'm useless at soldering, so I brought the switch to an electronics repair shop on Saturday. Apparently, someone named Emmet will be taking care of it, hopefully this week. That should work fine since I'll be dealing with the oil stuff (including the gearbox) and carbs in the meantime.