New To Me 1978 T140 With Issues

[RobinV]

Hello all. I am new to the forum. Glad to find you. I bought a beautiful T140 D. Have not been able to start due to electrical short. Paid to have some electrical trouble shooting done. A very nice guy. He straightened out some wiring issues. Yesterday lights and ignition worked. Today blows a fuse every time I turn the key switch. I want to run the engine as I have not been able to. Positive ground.
I want to run power from the negative post to my coils so to activate the ignition. Which coil terminal should I run it to, negative or positive. Any help appreciated. Just want to hear it run. Thanks, Robin.

 

[Rudie]

T140 D
Positive ground.

Not as standard. T140D were made only in the 79 and 80 model years, all Triumphs were negative ground from 79.

I want to run power from the negative post to my coils so to activate the ignition.

You do not.

As well as negative ground, all 79 on Triumphs were fitted with electronic ignition.

Paid to have some electrical trouble shooting done. A very nice guy.
Yesterday lights and ignition worked. Today blows a fuse every time I turn the key switch.

So clearly the bike is not "troubleshot" ... why not simply ask the "very nice guy" to finish the job you paid him for? Especially as clearly your electrical knowledge is very limited?

I want to run power from the negative post to my coils so to activate the ignition.

As I say, you do not, because the bike has (should have) electronic ignition.

As standard:-

. The electronics box for this is supplied by a Black wire from the battery negative terminal.

. The bike has two separate ignition coils; the electronics box switches the coils on and off to generate HT sparks.

. The electronics box is connected to one coil's negative terminal by a White/Black wire (insulation mainly White with thin Black tracer lines), that coil's positive terminal is connected to the other coil's negative terminal by a White/Pink wire; this is known as "connected in series".

. The electronics box is also connected directly to the second coil's positive terminal by a White/Yellow wire; the White/Yellow wire then continues from the second coil's positive terminal to the handlebar kill switch, the kill switch is connected to an ignition switch terminal, another ignition switch terminal is connected to the battery positive terminal through the fuse; the two ignition switch terminals are connected together - the ignition circuit is complete - when the ignition key is turned one or two 'clicks' from the "All Off" position.

If you wish to learn something about your bike's electrics, initially I suggest you simply trace the above circuit, ascertain if your bike is still fitted with its original electronic ignition - Lucas Rita, grey metal box mounted behind one of the sidepanels. If it has been replaced with an aftermarket e.i., regrettably "fitters" are apt to butcher standard wiring following aftermarket e.i. 'fitting' instructions none of which remotely resemble standard 79 on Triumph/Lucas electrics.

If you find your bike has aftermarket e.i., I can step you through the likely changes; however, imho if you want to ride the bike, quicker (and better?) would be to have someone who has already worked on the electrics recently to fix what could be just a minor issue, quick fix.

 

[RobinV]

Not as standard. T140D were made only in the 79 and 80 model years, all Triumphs were negative ground from 79.


You do not.

As well as negative ground, all 79 on Triumphs were fitted with electronic ignition.


So clearly the bike is not "troubleshot" ... why not simply ask the "very nice guy" to finish the job you paid him for? Especially as clearly your electrical knowledge is very limited?


As I say, you do not, because the bike has (should have) electronic ignition.

As standard:-

. The electronics box for this is supplied by a Black wire from the battery negative terminal.

. The bike has two separate ignition coils; the electronics box switches the coils on and off to generate HT sparks.

. The electronics box is connected to one coil's negative terminal by a White/Black wire (insulation mainly White with thin Black tracer lines), that coil's positive terminal is connected to the other coil's negative terminal by a White/Pink wire; this is known as "connected in series".

. The electronics box is also connected directly to the second coil's positive terminal by a White/Yellow wire; the White/Yellow wire then continues from the second coil's positive terminal to the handlebar kill switch, the kill switch is connected to an ignition switch terminal, another ignition switch terminal is connected to the battery positive terminal through the fuse; the two ignition switch terminals are connected together - the ignition circuit is complete - when the ignition key is turned one or two 'clicks' from the "All Off" position.

If you wish to learn something about your bike's electrics, initially I suggest you simply trace the above circuit, ascertain if your bike is still fitted with its original electronic ignition - Lucas Rita, grey metal box mounted behind one of the sidepanels. If it has been replaced with an aftermarket e.i., regrettably "fitters" are apt to butcher standard wiring following aftermarket e.i. 'fitting' instructions none of which remotely resemble standard 79 on Triumph/Lucas electrics.

If you find your bike has aftermarket e.i., I can step you through the likely changes; however, imho if you want to ride the bike, quicker (and better?) would be to have someone who has already worked on the electrics recently to fix what could be just a minor issue, quick fix.

I thank you for your response. This bike is listed as a 1978 on registration. It has a points ignition. I went by engine # to deduce year. I should return the bike to the person whom I paid to fix wiring issue. Otherwise, I just want to bypass everything and power the coils/points. I could then at least run the bike.

 

[atomsplitter]

Rudie is our resident expert on the early models, what he says will likely get you sorted.

 

[RobinV]

Rudie is our resident expert on the early models, what he says will likely get you sorted.

Hello again. I really do appreciate you folks responding to me. Electrical issue I may have sorted out. It seems that the master/ kill switch unit had an area where it was shorting to the handle bars. I fixed it. Now have power to coils without short.
So with the bike not having been started for 10 years, I put in fresh oil, and kicked many times and have oil returning to the reservoir.
Just getting some pops and a few flames out of the right side. Next is to figure out a static timing for a general start point. Any ideas you have will be applied.
I have been a VW mechanic for years so have some mechanical expertise. Just not so familiar with these bikes. Thankyou, and best regards, Robin.

 

[Rudie]

Rudie is our resident expert on the early models, what he says will likely get you sorted.

Thank you but I do not consider I am an "expert", I have just spent many years (too many according to the o.h. ) around old Triumphs, some information has stuck.

 

[Rudie]

Electrical issue I may have sorted out. It seems that the master/ kill switch unit had an area where it was shorting to the handle bars. I fixed it. Now have power to coils without short.

I have been a VW mechanic for years
the bike not having been started for 10 years, I put in fresh oil, and kicked many times

Whoever advised you to do the latter, ime you should reconsider taking any more advice from that person - any pre-Hinckley Triumph, several expensive components in the crankcase rely on splash lubrication by the crank when the engine is running; splash lubrication does not work when the engine is being kicked over.

To prevent any further damage to splash lubricated and valve components, I suggest reading and following the advice in Waking The Sleeping Beast; the author was a longtime Triumph owner, racer and engine builder. The only thing to do differently on a twin is reduce the amount of oil into the crankcase - "Waking The Sleeping Beast" was written for triple owners, triples have a larger crankcase volume than twins; twin in the US, I advise about 1.5 US pints of oil in the crankcase.

Just getting some pops and a few flames out of the right side. Next is to figure out a static timing

As the bike has points, I suggest the relevant section of the Triumph 73-78 750 twin Workshop Manual.

This bike is listed as a 1978 on registration. It has a points ignition. I went by engine # to deduce year.

Engine number is stamped on a raised flat area on the drive side (left hand) crankcase just under the block? The raised flat area also has several small "Triumph" logos stamped on it, the engine number and model code ("T140D"?) are stamped over these logos? The first figure of the five figure engine number is 1? The two letter date code to the left of the number is HA, JA, KA, NA, PA or XA?

The same model code, date code and number are stamped on the drive side of the frame headstock?

Triumph generally changed model years sometime between June and October in the previous calendar year - e.g. the first 79 model year bikes were built in calendar July 1978 - so it is not impossible for a Triumph built soon after the model year change to be first registered in the earlier calendar year.

However, 79 model year changes were significant; in addition from positive to negative ground and points to electronic ignition, the alternator and rectifier were changed from single phase AC to 3 phase, the fork yokes and headlight shell were changed to mount speedo, tacho. ignition switch and warning lights differently, the ignition switch and handlebar switches are different.

It is not impossible for a previous owner to have retro fitted 78 electrics and other parts to a 79 model year bike but the work would be significant to end up with generally poorer electrics.

 

[CarlS]

Thank you but I do not consider I am an "expert", I have just spent many years (too many according to the o.h. ) around old Triumphs, some information has stuck.

Don't sell yourself short!

 

[RobinV]

Don't sell yourself short!

Thanks so much for those links. Engine model specifies 1979. However, points are fitted and have power. I have a pair of new carbs I will fit and try again. Thx, Robin

 

[Rudie]

Engine model specifies 1979.

This is not clear. No T140D were built with points; for specifically a T140D to be working with points, a previous owner must have changed certainly at least the entire ignition circuit and all its components; depending how competent he (or she) was, possibly the entire electrical system; however, as I have posted already, that would not make any sense at all.

Otoh, if you have a T140E, they were completely different in the 78 and 79 model years:-

. Except for the last batch, 78 T140E was a US specific model, built to comply with the 1978 EPA emissions directive and FMVSS. These were built with positive ground electrics and points ignition.

. The very last batch of 78 T140E, all subsequent and all T140D were built with negative ground electrics and Lucas Rita electronic ignition.

 

[Dashfixer]

Does your bike have parallel intakes on the cylinder head? If it does then it is a T140E onwards. Also does it have an aluminium finned cover over the points? Again that was introduced on the T140E. If you post a decent photo of the bike from the right hand side and/or the engine number I can verify if it's a T140V (up to1978) or T140E/D (from 1979 onwards). As Rudie said there were a lot of changes on the T140 at 1978/1979, and you really do need to identify the model and work to that datum.

 

[Dashfixer]

Triumph did make some hybrid T140 towards the end of 1978. These were basically T140V bikes with positive earth, points ignition, but with a T140E engine fitted, parallel intakes on the cylinder head. I've attached some pics. If your bike looks like this then you have a T140D for sure and someone has fitted old T140V electrics to it. Also attached is a table of engine numbers.

 

[Dashfixer]

It would be handy to get hold of a Triumph T140 factory workshop manual and one or both of these two books.

 

[RobinV]

Triumph did make some hybrid T140 towards the end of 1978. These were basically T140V bikes with positive earth, points ignition, but with a T140E engine fitted, parallel intakes on the cylinder head. I've attached some pics. If your bike looks like this then you have a T140D for sure and someone has fitted old T140V electrics to it. Also attached is a table of engine numbers.

It appears that the heads are parallel port. The rocker covers are finned as well as the points cover. The frame number is a bit hard to read, but looks like it is T140V H (or N) X01385.The engine pic is clear. Thanks for your help. Robin

 

[RobinV]

It appears that the heads are parallel port. The rocker covers are finned as well as the points cover. The frame number is a bit hard to read, but looks like it is T140V H (or N) X01385.The engine pic is clear. Thanks for your help.

It appears that the heads are parallel port. The rocker covers are finned as well as the points cover. The frame number is a bit hard to read, but looks like it is T140V H (or N) X01385.The engine pic is clear. Thanks for your help. Robin

The bike is still filthy. Wanted to get it running first.

 

[Dashfixer]

Manufacture date is February 1979. So in theory your bike should be negative earth electrics with Electronic ignition. It looks like it's been partially altered by a previous owner hence the incorrect for points 6v coils. They were standard fit for E.I. Also I understood that the first T140D were exported to the USA and had cast wheels.

 

[RobinV]

Manufacture date is February 1979. So in theory your bike should be negative earth electrics with Electronic ignition. It looks like it's been partially altered by a previous owner hence the incorrect for points 6v coils. They were standard fit for E.I. Also I understood that the first T140D were exported to the USA and had cast wheels.

Thankyou for that information. I am going out to replace the rear master cylinder now.

 

[Rudie]

The frame number is a bit hard to read, but looks like it is T140V H (or N) X01385.

Manufacture date is February 1979.

Only the bike's engine was built in February (B) of the 79 (A) model year.

The frame originally left Meriden with an engine built in July (H) or October (N) of the 78 model year (X) - a frame number was copied from the engine installed in it during assembly, bikes left Meriden with "matching numbers" as one of the measures to make them less attractive to, harder work for, thieves.

Note "model year" above is significant for your bike's cycle parts - the original engine, probably the whole bike, was actually built in the 1977 calendar year, because:-

Triumph generally changed model years sometime between June and October in the previous calendar year

This bike is listed as a 1978 on registration. It has a points ignition. I went by engine # to deduce year.

Manufacture date is February 1979. So in theory your bike should be negative earth electrics with Electronic ignition. It looks like it's been partially altered by a previous owner hence the incorrect for points 6v coils.

I've attached some pics. If your bike looks like this then you have a T140D for sure and someone has fitted old T140V electrics to it.

The bike cannot possibly be a T140D, only this bike's engine was built in February 1979, the rest of the bike was built between nine months and a year before any production T140D. The positive earth/ground electrics and points are contemporary with the bike's frame number; the only alteration by someone is the later engine.

It is finally much clearer why the bike has all the details of a pre-79 bike; fixating on the engine number to the exclusion of the frame number was unnecessarily confusing.

The points (and mechanical auto advance?) on the T140D engine were probably taken from the original T140V engine, the T140D engine was probably sold without the ignition parts, the original T140V's ignition parts matched the rest of the electrics without alteration whereas fitting the Lucas Rita EI would have required some alterations (not many). Nevertheless, given this bike's electrics, if it was fitted with 6V coils, that was just plain idiocy.

Triumph did make some hybrid T140 towards the end of 1978. These were basically T140V bikes with positive earth, points ignition, but with a T140E engine fitted, parallel intakes on the cylinder head.

Aside but the 78 T140E were made from February to probably June 1978. They are not really "hybrid" because everything on the engine below the head is the same on the T140V and TR7RV Meriden continued to build for everywhere except the US, 78 T140E are just another version.

The T140E's Amal Mk.2 carbs fitted on the parallel port head were necessary for the model to meet the 1978 EPA emissions levels, required on all bikes built after 31st December 1977 for sale in the US. T140E also had changes to oil vapour venting to meet the emissions levels - frame vented into the exhaust rockerbox, primary vented into the airbox.

Compared to 78 T140V and TR7RV, 78 T140E also had changes to the electrics in the headlight shell to meet the 1978 FMVSS requirement for lights on with ignition - pilot and tail bulbs are turned on by the ignition switch.

I say "to probably June 1978" because the last batch of "78" T140E were actually to 79 spec - negative ground electrics, 3 phase alternator, electronic ignition, different speedo, tacho, ignition switch, warning lights mounting, etc., etc.

 

[RobinV]

Only the bike's engine was built in February (B) of the 79 (A) model year.

The frame originally left Meriden with an engine built in July (H) or October (N) of the 78 model year (X) - a frame number was copied from the engine installed in it during assembly, bikes left Meriden with "matching numbers" as one of the measures to make them less attractive to, harder work for, thieves.

Note "model year" above is significant for your bike's cycle parts - the original engine, probably the whole bike, was actually built in the 1977 calendar year, because:-





The bike cannot possibly be a T140D, only this bike's engine was built in February 1979, the rest of the bike was built between nine months and a year before any production T140D. The positive earth/ground electrics and points are contemporary with the bike's frame number; the only alteration by someone is the later engine.

It is finally much clearer why the bike has all the details of a pre-79 bike; fixating on the engine number to the exclusion of the frame number was unnecessarily confusing.

The points (and mechanical auto advance?) on the T140D engine were probably taken from the original T140V engine, the T140D engine was probably sold without the ignition parts, the original T140V's ignition parts matched the rest of the electrics without alteration whereas fitting the Lucas Rita EI would have required some alterations (not many). Nevertheless, given this bike's electrics, if it was fitted with 6V coils, that was just plain idiocy.


Aside but the 78 T140E were made from February to probably June 1978. They are not really "hybrid" because everything on the engine below the head is the same on the T140V and TR7RV Meriden continued to build for everywhere except the US, 78 T140E are just another version.

The T140E's Amal Mk.2 carbs fitted on the parallel port head were necessary for the model to meet the 1978 EPA emissions levels, required on all bikes built after 31st December 1977 for sale in the US. T140E also had changes to oil vapour venting to meet the emissions levels - frame vented into the exhaust rockerbox, primary vented into the airbox.

Compared to 78 T140V and TR7RV, 78 T140E also had changes to the electrics in the headlight shell to meet the 1978 FMVSS requirement for lights on with ignition - pilot and tail bulbs are turned on by the ignition switch.

I say "to probably June 1978" because the last batch of "78" T140E were actually to 79 spec - negative ground electrics, 3 phase alternator, electronic ignition, different speedo, tacho, ignition switch, warning lights mounting, etc., etc.

That is some great information. It certainly helps to me discern the changes in my model here. Thankyou for that.