New To Me T 140 Saga Continues

[RobinV]

I hope you don't mind me posting again on my 15 year idle 1978 T 140. Have the weekend off so I can play with the motorcycle. The person I paid to fix wiring for me put me on hold last I called and so I believe I am personna non grata there. Oh well.
I do have power to lights, blinkers and coils after repairing the master/ kill switch short. Good.
With some great info from a member here, I nave access to a workshop manual.
So I pulled the plugs, and cold, (after 15 years) I have 120 psi #1 and 115 psi #2. OK. I read a text provided here and pulled valve adjust covers. All looked clean, and with my hand I figure .006 lash with all. Lubed the area with plenty of oil and squirted some down the PR tube so as to make the lifters happy. Turned key on and I have current to coils. Nothing however goes to my points So no spark. No signal sent to coils to fire. I am getting closer I sense, to a startup. (hope).
So Saturday I will be looking to the manual to trace the coils to points route. I read that using 6 volt coils would produce a hot spark. Any truth to this rumour? Thanks so much for your help. Robin.

 

[Rudie]

nave access to a workshop manual.
valve adjust
figure .006 lash with all.

Too tight for the inlets, should be 0.008" - workshop manual page GD3 or, if you are reading the pdf, page 15. 0.006" is correct for the exhausts.

current to coils. Nothing however goes to my points So no spark. No signal sent to coils to fire.

There is no "signal", points are part of each coil's circuit between battery negative and battery positive; when a set of points opens, that breaks the circuit through the connected coil's primary windings; circuit broken, the magnetic field that was around the primary windings (charging the secondary windings) collapses, causes the energy stored in the coil's secondary windings to discharge, that should be the spark across the connected plug.

As the bike has stood unused for so long, first check should be the points are actually opening, not stuck together. Spark plug you know works, connect it to one of the bike's plug caps, lay the plug on the cylinder head, turn on the ignition switch, ensure the kill switch is on, flick the moveable point in each set while looking for a spark across the plug on the head.

Also be suspicious of plug caps that screw into the ends of plug leads, Triumph did not fit them as standard after 70 and they are a continuous pita; if they are resistive caps (e.g. NGK), the resistor is another thing to fail.

read that using 6 volt coils would produce a hot spark.

Whoever wrote that is an idiot, no idea how ignition coils work.

Volts numbers on a coil are a shorthand (to the point of misleading the paddlers at the shallow end of the gene pool ... ):-

. Coils switched by points, the primary windings are designed to draw between 3 and 4 Amps with the rated Volts across the coil's primary terminals.

. Connecting Amps and Volts is Ohm's Law - Volts equals Amps multiplied by Ohms (resistance):-

.. "12V" coil's primary windings have a resistance between 3 Ohms and 4 Ohms, 12V applied across the primary terminals, Ohm's Law says the coil will draw the designed between 4 and 3 Amps respectively;

.. otoh, "6V" coil's primary windings have a resistance between 1.5 Ohms and 2 Ohms, 6V applied across the primary terminals, Ohm's Law again says the coil will draw the designed between 4 and 3 Amps respectively;

.. otoh2, "6V" coil's primary windings having a resistance between 1.5 Ohms and 2 Ohms, if 12V is applied across the primary terminals, Ohm's Law says the coil will draw between 8 and 6 Amps respectively ...; Amps make heat, the coil will overheat and fail.

Aside, twin with 12V electrics, not impossible to fit 6V coils and switch them with points, Norton did it on early 1970's Commandos; however, crucially, Norton fitted a ballast resistor in the coils' supply that reduced the bike's 12V to 6V across the coils' primaries (Norton intended to fit an electric starter but took five years to work out how to do it ... ).

If your bike has 6V coils and is really a 79, standard electronic ignition requires 6V coils because the coils are connected to the e.i. completely differently from points, your bike's points were installed by a p.o.; if he did that without also fitting a ballast resistor in the coils' supply, another possible reason for your bike's "no spark" is the coils' primaries are burnt out.

looking to the manual to trace the coils to points route.

The manual I linked will only help you if your bike is pre 79.

If your bike is a 78 T140V, its ignition circuit should be as shown on manual page 22/pdf page 191.

Otoh, if your bike is a 78 T140E, while its ignition circuit should be as shown on manual page 22/pdf page 191, the "OFF SIDE HEAD" switch (the lever switch on top of the headlight shell) and its wiring are mostly different.

 

[RobinV]

Too tight for the inlets, should be 0.008" - workshop manual page GD3 or, if you are reading the pdf, page 15. 0.006" is correct for the exhausts.


There is no "signal", points are part of each coil's circuit between battery negative and battery positive; when a set of points opens, that breaks the circuit through the connected coil's primary windings; circuit broken, the magnetic field that was around the primary windings (charging the secondary windings) collapses, causes the energy stored in the coil's secondary windings to discharge, that should be the spark across the connected plug.

As the bike has stood unused for so long, first check should be the points are actually opening, not stuck together. Spark plug you know works, connect it to one of the bike's plug caps, lay the plug on the cylinder head, turn on the ignition switch, ensure the kill switch is on, flick the moveable point in each set while looking for a spark across the plug on the head.

Also be suspicious of plug caps that screw into the ends of plug leads, Triumph did not fit them as standard after 70 and they are a continuous pita; if they are resistive caps (e.g. NGK), the resistor is another thing to fail.


Whoever wrote that is an idiot, no idea how ignition coils work.

Volts numbers on a coil are a shorthand (to the point of misleading the paddlers at the shallow end of the gene pool ... ):-

. Coils switched by points, the primary windings are designed to draw between 3 and 4 Amps with the rated Volts across the coil's primary terminals.

. Connecting Amps and Volts is Ohm's Law - Volts equals Amps multiplied by Ohms (resistance):-

.. "12V" coil's primary windings have a resistance between 3 Ohms and 4 Ohms, 12V applied across the primary terminals, Ohm's Law says the coil will draw the designed between 4 and 3 Amps respectively;

.. otoh, "6V" coil's primary windings have a resistance between 1.5 Ohms and 2 Ohms, 6V applied across the primary terminals, Ohm's Law again says the coil will draw the designed between 4 and 3 Amps respectively;

.. otoh2, "6V" coil's primary windings having a resistance between 1.5 Ohms and 2 Ohms, if 12V is applied across the primary terminals, Ohm's Law says the coil will draw between 8 and 6 Amps respectively ...; Amps make heat, the coil will overheat and fail.

Aside, twin with 12V electrics, not impossible to fit 6V coils and switch them with points, Norton did it on early 1970's Commandos; however, crucially, Norton fitted a ballast resistor in the coils' supply that reduced the bike's 12V to 6V across the coils' primaries (Norton intended to fit an electric starter but took five years to work out how to do it ... ).

If your bike has 6V coils and is really a 79, standard electronic ignition requires 6V coils because the coils are connected to the e.i. completely differently from points, your bike's points were installed by a p.o.; if he did that without also fitting a ballast resistor in the coils' supply, another possible reason for your bike's "no spark" is the coils' primaries are burnt out.


The manual I linked will only help you if your bike is pre 79.

If your bike is a 78 T140V, its ignition circuit should be as shown on manual page 22/pdf page 191.

Otoh, if your bike is a 78 T140E, while its ignition circuit should be as shown on manual page 22/pdf page 191, the "OFF SIDE HEAD" switch (the lever switch on top of the headlight shell) and its wiring are mostly different.

Such a wealth of information. Thankyou. I will follow up with this over the weekend. Robin

 

[Rocky]

Not my post or issue, but Rudie, your replies are indeed, a wealth of information.

 

[RobinV]

I am happy to report some success here. Actually, very happy. I have rectified the blowing fuse issue. (so far at least). After a 15 year hiatus, the old girl has come to life.! I spent the day working on it.
Once assured that I no longer had electrics shorting, and with some pointers from a kind member here, I went through the Amal Mark 2s once again. Installed them and once more had some serious popping and fireworks displays. I had earlier read a post re this issues' possible cause. Crossed spark plug wires. But I just had it all looked over. New wires included. Switched them.
All valves lubed and some extra oil down the cylinder. Fresh oil in the reservoir.
Set chokes, and kicked. Hmm, a happy initial sound, and a too advanced kickback from the old Brit.
Retarded the timing some, and it start!ed!! I only ran it for 4-5 seconds and shut it down as I have no oil light. Sounded very nice. I decided that a pint was in order and shall resume tomorrow. Very pleased. Geez it sounded good.!
It's the little things in life that can bring such a joy.!

 

[RobinV]

I see that my oil return looks to have some bubbles, and looks a bit foamy. So I will install an oil pressure gauge this morning to assure a good reading.

 

[atomsplitter]

Great news. I had the same feeling when I got a 98 Triumph Trophy 1200 to start after buying it as a non-runner. It's fun when things start to work again like they were designed to.

 

[Rudie]

it start!ed!!

wealth of information

Thank you both, I am pleased when it helps.

However, I managed to miss:-

Crossed spark plug wires

... My excuse is my T160 has not had points in over forty years ...

Originally, the plug wires on Triumph twins were connected drive side coil to drive side plug, timing side coil to timing side plug. If that is how your bike's were and you have had to swap them, the 'fault' is actually in the points compartment in the engine ...

Looking there, there is one points set on the left of the compartment (i.e. more towards the rear of the engine) and the other points set on the right of the compartment (i.e. more towards the front of the engine). As standard Triumph did not use logic - the points set on the left of the compartment is connected to the timing side (right hand) coil and condenser, the points set on the right of the compartment is connected to the drive side (left hand) coil and condenser ... - if the points wires have been connected logically, each points set is connected to the 'wrong' coil/condenser/cylinder ...

will install an oil pressure gauge

+1.

However, check the male fitting supplied to fit the timing cover and, if it is common NPT (US National Pipe Tapered), be very careful installing it in the timing cover, because the cover thread is NPS (National Pipe Straight, now a very uncommon threadform ), the timing cover casting is very thin around part of the thread and it is very easy to crack the cover with a tapered male thread.

NPT or NPS male thread, I always expect it to install using only fingers; only NPS thread do I use a wrench just for the final 'nip up' to the cover.

oil return looks to have some bubbles, and looks a bit foamy

Correct - scavenge side of an oil pump always has a greater capacity than the feed side (to obviate any possibility of draining oil building up in the bottom of the crankcase) so occasionally the scavenge side of the pump will suck just vapour.

 

[RobinV]

Thank you both, I am pleased when it helps.

However, I managed to miss:-

... My excuse is my T160 has not had points in over forty years ...

Originally, the plug wires on Triumph twins were connected drive side coil to drive side plug, timing side coil to timing side plug. If that is how your bike's were and you have had to swap them, the 'fault' is actually in the points compartment in the engine ...

Looking there, there is one points set on the left of the compartment (i.e. more towards the rear of the engine) and the other points set on the right of the compartment (i.e. more towards the front of the engine). As standard Triumph did not use logic - the points set on the left of the compartment is connected to the timing side (right hand) coil and condenser, the points set on the right of the compartment is connected to the drive side (left hand) coil and condenser ... - if the points wires have been connected logically, each points set is connected to the 'wrong' coil/condenser/cylinder ...


+1.

However, check the male fitting supplied to fit the timing cover and, if it is common NPT (US National Pipe Tapered), be very careful installing it in the timing cover, because the cover thread is NPS (National Pipe Straight, now a very uncommon threadform ), the timing cover casting is very thin around part of the thread and it is very easy to crack the cover with a tapered male thread.

NPT or NPS male thread, I always expect it to install using only fingers; only NPS thread do I use a wrench just for the final 'nip up' to the cover.


Correct - scavenge side of an oil pump always has a greater capacity than the feed side (to obviate any possibility of draining oil building up in the bottom of the crankcase) so occasionally the scavenge side of the pump will suck just vapour.

I purchased an oil P gauge. I am aware of the thread differences as I have encountered this with some Chinese made oil senders over the years. And sure enough, the threads were not correct for my machine. Returned it and tested the stock sender unit. reinstalled it. It works well. Just that it lights the green light to the left.
Kicked the bike many times having changed the oil initially. The green light went out quickly. After kicking with plugs removed, it took a good several seconds to come back on. Good sign. Plugs back in. Key on.
Bike fired right up. Light stayed out. Oil was white and obviously tainted with water. I was careful to observe the light while running lower RPM with a large fan on.
After 5 oil changes, running bike between.them, I now have almost normal looking oil. No untoward noises.
Next issue is a #2 cylinder firing weakly compared to #1. The exhaust never got hot as the #1 did. Pulled the spark plug and looked inside. Looks good in there.
Compression at 120lbs. Fired it up and as it was running,(it really wants to), I sprayed some brake cleaner around the intake to carb boot. Just about killed it. Most likely this indicates an intake leak . Then again, the carburetor may be deficient in flow. The points on that cylinder may have closed down. I may just have a weak coil. Obviously the old girl wants some attention from me. Can do.
Enough fun for today however. Thanks for all of your help. Best, Robin.

 

[RobinV]

I purchased an oil P gauge. I am aware of the thread differences as I have encountered this with some Chinese made oil senders over the years. And sure enough, the threads were not correct for my machine. Returned it and tested the stock sender unit. reinstalled it. It works well. Just that it lights the green light to the left.
Kicked the bike many times having changed the oil initially. The green light went out quickly. After kicking with plugs removed, it took a good several seconds to come back on. Good sign. Plugs back in. Key on.
Bike fired right up. Light stayed out. Oil was white and obviously tainted with water. I was careful to observe the light while running lower RPM with a large fan on.
After 5 oil changes, running bike between.them, I now have almost normal looking oil. No untoward noises.
Next issue is a #2 cylinder firing weakly compared to #1. The exhaust never got hot as the #1 did. Pulled the spark plug and looked inside. Looks good in there.
Compression at 120lbs. Fired it up and as it was running,(it really wants to), I sprayed some brake cleaner around the intake to carb boot. Just about killed it. Most likely this indicates an intake leak . Then again, the carburetor may be deficient in flow. The points on that cylinder may have closed down. I may just have a weak coil. Obviously the old girl wants some attention from me. Can do.
Enough fun for today however. Thanks for all of your help. Best, Robin.

Hello all. Well, I am somewhat driven I suppose. As I had a few moments until dinner was ready, I decided to follow up on some ideas.
I went out and pulled plugs. Ignition on. Looked for spark. Even on both sides. OK. Next thought was intake leak. There is a hose going to each intake to balance vacuum. I pulled the hose and recognized that is was too large of an id to seal properly. Replaced with a smaller hose. Presto, and voila, the cylinder cleared out unburned content and started to run the pipes just as hot as the other side. Now sounds strong and even. OK. Now I can sleep soundly tonight. Robin

 

[Rudie]

oil P
tested the stock sender unit. reinstalled it. It works well. Just that it lights the green light to the left.

If you do not have one already, Triumph parts books are free to read online.

They show standard warning light bulb holders and shades are separate parts, the same holder fits in all four/three (79 on/pre 79) shades, just the shade lens colours are different. The aluminium bulb holders are a tight push fit in the black (sometimes grey) shade tubes and the only purchase on the bulb holder to pull it and shade apart is the aluminium ridge on the bulb holder visible at the bottom of the shade tube. If a bulb holder is really hard to pull out of a shade, warm the shade tube with a hot air gun (on low) or hairdryer.

Otoh, if the idiot lights are later gofaster (LED?) accessories, they can be one piece.