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Pilot Light VS Head Light?

12K views 43 replies 9 participants last post by  Triton Thrasher 
#1 ·
Finally got around to getting a ground for the pilot light and installed it the other day. I'm running a 12V/23W Quartz Halogen in the pilot and use that in lieu of running the headlight all the time (as required where I live). It actually looks brighter than the headlight in daylight hours. The headlight bulb is a 12V, 45/40W. I'm doing this as it seemed the headlight was drawing more than the alternator was charging the battery unless running at high RPM's. Am I right in assuming the pilot light is drawing slight more than half the wattage of the head light? And, if so, will this make a significant difference in keeping the battery charged?

Also the 'Owners Handbook' states 'the motor should be maintained at a speed in excess of 2100 r.p.m.' to prevent discharging the battery. A local mechanic who got the bike running better than it has in years told me the r.p.m. should be kept above 3000 to 3500. Which sounds right?
 
#2 ·
Yes, 23 W draws about half the current of 45 W.

Don't obsess about rpm. Normal road riding and especially acceleration, is best done at over 3,000 rpm. Going slow in town, you'll be doing much less rpm a lot of the time.

The battery does discharge at idling rpm, but gets charged again when revs rise.
 
#3 ·
Hi Slick, I don't have a real solution, but what you are doing will for sure help. Here's a few thoughts from my experience. Very easy for me to spend an hour in town.
I fought a charging problem, where battery would tend to go low in town, so low headlamp may look dim. Took only about 15min of constant stop lights. Finally I cleaned & dielectric greased every single connector & ground on the bike. That made a decided difference for the better. I'm running 40/45 headlamp on all the time also. Keep it on low beam. I also went with LED speedo & tach bulbs which saves some juice & also is much brighter so you can actually read gauges at night or in tunnels. I ride at night often. My bike is all stock, original with points. Electronic ignition uses a little more juice that points.
I did a lot of testing this summer by riding bike in all conditions with a volt meter zip tied to the bars. I can't see to locate the test sheet, but 2100rpm is already giving a decent charge. 3000-3500 is charging quite strongly. Even at 1500 it was wanting to charge. The discharge stoplight after stoplight is not too bad at first but after about 20-30min the battery can't quite keep up & volts starts to drop off at idle. Stop lamp bulb sucks a fair amount of juice & many times the brake must be held to keep bike from rolling at a stop light. Plus turn signals sucks 42w intermittently while flashing.
Since the charging system is not very powerful it's most important to have a good strong battery to store as much as it can. I find the motobatt agm battery can take a charge quicker than normal battery & has more reserve power in town.
Do you have a volt meter? While riding on highway it will be over 14v. At stoplights about 12.2v or so. After repeated stop lights will be 11.8-11.5v. I find once I get down to 11.5 the bike may be hard to start or want to kick back on starting. Normal full charge battery next morning will be right about 12.6-7v.
Again my rotor, stator, rectifier, zener are all stock & original from new.
Now... this is most important... when you have the rotor off always store it inside the stator & put a specially made metal rings called keepers on it. New rotors come with the keeper ring, which is 2 thick 1/2 round metal straps bent to stick to magnets. If the rotor is left out it can loose magnetism fairly quickly.
I'll see if I can dig up my test sheets so I can be more specific.
Don
 
#12 · (Edited)
Hi,

Electronic ignition uses a little more juice that points.
Boyer-Bransden state 0.05A (i.e. five-hundreths of an Amp) for the Mk.4; I very much doubt that any other e.i. is significantly different.

2100rpm is already giving a decent charge.
Triumph had a Service Bulletin Number (Twin) 1/78 dealing with full time lighting use. This was also in the 1978 Dealer Service Seminal Manual. It basically stated at 2100 RPM the electrical output balanced the electrical draw with the lights on.
:confused: Perhaps someone else could do the calculation, with the figures taken from the 1974 T140V/TR7RV Triumph workshop manual, Lucas's own figures and Ohm's Law (as opposed to the 1974 Mickey Mouse annual)?

rotor, stator,
all stock & original from new.
Like the o.p., you might want to consider either LED in the more-powerful lamps and/or a more-powerful alternator.

If you have a running problem due to a discharged battery you (or your mechanic) can install a 2MC Capacitor.
Aiui, the capacitor can provide a discharge to start the bike if the battery is flat, then the spinning alternator can both supply the ignition and charge the battery. Otoh, if the spinning alternator can't keep the battery charged, I'm not sure I see how it can charge a capacitor to discharge continuously?

only a fool would run without a lit headlamp.
Having managed without one (except obviously at night and in poor daytime visibility) for 43 years - including 20 years living commuting and working in London ... :finger

Finally, Goffy's opinion of LED head and pilot bulbs is just one, and assumes he's keeping up with developments. For more positive ones, in addition to "Rambo", enter "dynamo regulator conversions" into your preferred internet search engine and look at what it returns about http://www.dynamoregulatorconversions.com/. Owner Peter has spent much time and money developing his own, including LED replacement headlamp bulbs - chronicled in his posts on http://www.ikba.co.uk, where he posts as "thumpersloper".

Hth.

Regards,
 
#4 ·
If it makes you feel any better early Honda 750's had a battery discharge problem after Headlamp On Laws went into effect.

Triumph had a Service Bulletin Number (Twin) 1/78 dealing with full time lighting use. This was also in the 1978 Dealer Service Seminal Manual. It basically stated at 2100 RPM the electrical output balanced the electrical draw with the lights on. Now if you still have the original rotor/stator that may need to be upped a few hundred RPM to compensate for age & wear. I think there was another Bulletin dealing with older bikes somewhat the same but the RPM level was in the 2600 RPM range. (working from memory here not necessarily a good thing)

While 2100 RPM doesn't sound unreasonable if you are in a congested Metro/Burb area it can be a problem. I found the first tip off to a pending discharge problem was the turn signal flash rate.

If you have a running problem due to a discharged battery you (or your mechanic) can install a 2MC Capacitor. I did that on my '70 many years ago and haven't had a problem since. However it need to be wired so it not a drain on the battery with the ignition off.

I have never had a problem with my '78 T140 BUT I converted the headlamp to a 36W H4 bulb.


K
 
#6 ·
.......................I think there was another Bulletin dealing with older bikes somewhat the same but the RPM level was in the 2600 RPM range. (working from memory here not necessarily a good thing)

While 2100 RPM doesn't sound unreasonable if you are in a congested Metro/Burb area it can be a problem. I found the first tip off to a pending discharge problem was the turn signal flash rate.

If you have a running problem due to a discharged battery you (or your mechanic) can install a 2MC Capacitor. I did that on my '70 many years ago and haven't had a problem since. However it need to be wired so it not a drain on the battery with the ignition off.

I have never had a problem with my '78 T140 BUT I converted the headlamp to a 36W H4 bulb. K
Interesting info K, thank you. BTW, how is your injured buddy?

Happily I rarely get stuck in suburbia, so my modest 12v 7A/hr battery has served me well enough. The Pazon EI will also tolerate very low volts, and this is an advantage also.

Whilst headlamp on is not required by law here (yet), only a fool would run without a lit headlamp. The '72 headlight could never have been designed to be used in total darkness as on the one occasion I travelled the highway on mine, I could see bugger all!! So it's nigh on useless really.

To be better seen in built up areas, or where I encounter heavier traffic, I have installed a 300 lumen bicycle strobe light on the handle bar. I feel this may attract the attention of the inattentive in a way the weak incandescent Trumpy lamp cannot.

A change in the head light bulb, without also attending to reflector and lens, is not going to improve things much IMHO. RR
 
#5 ·
I'm running a 12V/23W Quartz Halogen in the pilot and use that in lieu of running the headlight all the time (as required where I live). It actually looks brighter than the headlight in daylight hours.
G'day Slick Shifter. I have used these, and whilst they are an excellent alternative to the headlamp, they did not last all that long on my '72 T120. I suspect vibration got to them.

As they were relatively expensive, I chose not to go on replacing them. I hope you do better out of them than I did. RR
 
#11 · (Edited)
Hi,

12V/23W Quartz Halogen in the pilot
It actually looks brighter than the headlight
The headlight bulb is a 12V, 45/40W.
Been using qh pilot bulbs since late '79 or early '80; yes, they're better than the Lucas 45/40 (or 50/40) BPF headlamp bulb, because the Lucas headlamp bulbs - and, as said, the standard lens/reflector - are crap.

In addition, because the pilot bulb is by definition off the focal point of the lens, the pilot light spreads in a wide arc - rather than being focussed ahead of the bike, as the headlamp is necessarily - which helps to make the bike more visible to others not so directly in front of it. :thumb

the 'Owners Handbook' states 'the motor should be maintained at a speed in excess of 2100 r.p.m.' to prevent discharging the battery. A local mechanic who got the bike running better than it has in years told me the r.p.m. should be kept above 3000 to 3500.
"r.p.m." is not a sensible measure of whether the battery's being charged or not. But your "local mechanic" is about right; whoever reckoned "2100 r.p.m. to prevent discharging the battery" either couldn't count or didn't know basic electrics (a sadly not-uncommon occurrence :().

Assuming the original RM21 alternator, Lucas rated that for 10.5 Amps @ 5,000 rpm, also 120 Watts. The original alternator is also single-phase; Lucas stated those produce 75% of rated output @ 2,400 rpm, so 90W or a gnat's under 8A.

Headlamp dip is 40W, coils draw about the same; unfortunately, unlike the pre-'71 headlamp toggle switch, the standard switch on your bike doesn't turn the pilot lamp off when the headlamp's on and vice versa, so originally 6W for that; tail lamp is 5W, speedo. 'n' tacho. illumination are 3W each. Total 97W, or just over 8A (the calculation is Watts = Amps x Volts, aka P=IE).

As you can see, consumption and generation @ 2,400 rpm is about the same, generation falls/rises quickly particularly at low rpm, consumption essentially doesn't, the above calculation doesn't include intermittent consumers like 21W brake lamp, two 21W indicators and horn. Ime, at least an additional Amp over and above constant consumption is necessary to keep the battery charged for intermittent consumers.

Few additional things to bear in mind:-

. Headlamp main adds another 5W (~0.5A) to the consumption.

. While fitting a qh pilot bulb cuts consumption when its used instead of the headlamp, because the toggle switch doesn't turn the pilot off when the headlamp's on, it adds 17W (~1.5A) to the overall consumption when you must use the headlamp.

. An original alternator is now over forty years old, everything else being equal, how much a forty-year old alternator can generate depends on the forty-year-old magnetism in the rotor; magnetism attenuates with age; it can be really slow, or other factors can speed it up ...

. Even when the bike was new with original bulbs, there was very little spare between generation and consumption; you maybe want to consider LED and/or a more-powerful alternator? If you go for LED, ask questions before you spend money, or you could end up wasting the latter. :(

12V/23W Quartz Halogen in the pilot and use that in lieu of running the headlight all the time (as required where I live).
With the standard wiring, the tail lamp is on too. In daylight, the standard rear lamp is not very good at displaying the difference between tail and brake. This gets worse the brighter the sunlight. As you must have a "headlight" on all the time, have you considered a simple wiring mod. that would turn on just the pilot lamp with the ignition switch and leave all other lamps to be switched on and off by the toggle switch? Simple plug-'n'-play, easily reversible?

Hth.

Regards,
 
#23 ·
My dear old Scottish mate, I should have guessed.

You have eyes TT. Try using them, and with the application a shred of common sense you'll have your "demonstration". RR :grin2:

Don't you love these new smileys? You do get them up there in the Highlands?
 
#22 ·
Hi RetroRod, We used to ride in the black of night often, on '70,71,72,73 Triumphs. Out in the country with no other lights from houses or anything. I still do. All these Triumphs had stock headlamps & bulbs. My light was fine until it burned out. Both beams out & glass was black indicating an air leak into the bulb... No problem, just get another bulb right? I go to Raber's. Get a bulb. Put it in & it looks fine in the daylight & looks quite bright to look at it in darkness. However, you cannot see where you are going. Most odd... Low beam lights up the street, but it's all spread out & you can only see 15-20' clearly. High beam is better, but still odd & no distinct beam. Very unsafe especially at normal highway speeds. I'm a pack rat & collector so I kept all my old Triumph parts from day one on my '73 Tiger so I took a look at the few prior burned out bulbs. Very interesting... The old bulbs that worked fine of various brands, Lucas, Stanley, & an unknown brand all had a vertical deflector in front of the filament. However the Raber's bulb 48/48w had a horizontal deflector for the filament. John's 69 Bonnie was the same: horizontal. He couldn't see either. So I got a replacement even though lower watts, but has the vertical deflector. Both our bikes work good now. Last winter I rode in pitch dark for several hours at 60mph. Was like the old days not a problem. I looked into H4 bulb but would have to change connectors & the watts are higher on it. Not sure how it would really shine. Point of all this is the bulb must match the reflector/lens to shine properly on road. The higher watts worries me due to battery discharge in town. Recently some powerful LED bulbs with braded heat sinks have come out to repl H4 but how will they shine? They are low watts though. Around 30 as I recall. They should fit into the larger headlamp shells fine, but again the reflector?? Since I got the proper bulb back in I'm just keeping the stock set up for now as it feels safe to me.
Don
 
#25 ·
The old bulbs that worked fine of various brands, Lucas, Stanley, & an unknown brand all had a vertical deflector in front of the filament. However the Raber's bulb 48/48w had a horizontal deflector for the filament.
Don
How very interesting! More so for those who do any night riding.

Yes, my headlamp would give a generalised, weak amber glow extending perhaps 20 ft ahead, but of no value at all in seeing the road. I just assumed it was the reflector/lens on this lamp and that was that. In hindsight, the old '50's '60's Trumpy's were all good for night riding so why not now? Very observant of you.

Scurrying down to to the workshop I see the installed bulb has a the horizontal deflector, sure enough. The bulb purchased yesterday does not even have the pretence of a deflector, so it'll be something of a "candle in the window" kind of light. A large stop/tail :grin2:

I did think the QH pilot is a good idea, if one can get some life out of them.

LED? well we see many creeping into the automotive sphere, but they are undoubtedly with their own reflectors/lenses etc. Whilst some bulbs are offered to us old Trumpy owners, our positive ground system will limit what we can get/have.

As you've found, the QH upgrade can be a PITA and so unless the night riding is something one must do, then that just leaves being seen as the priority I think. RR
 
#24 ·
Lighting

I have LED bulbs ( and Eagle Eyes) mounted in all holders (except the headlight) and run two multi LED daylight running lights, these are mounted adjacent to the front indicators. An LED strip light is also mounted on top of the number plate connected to the brake light circuit. When my brakes are applied, night becomes day, that's the way I like it! See and be seen.
 
#30 ·
Thanks

Thanks for all the replies. I hoped for replies from some of the 'experts' on the forum and my wish was greatly exceed. Once again I learned something new. As usual when reading the forum. You would think being 65 and riding Triumphs for going on 45 years I'd know more, but electricity has always been a mystery to me.
 
#32 ·
Stuart, It's time for a truce and agree to disagree I think. :)

Of course anyone who disagrees with this oracle is a fool. One cannot escape the facts:)

It's good to have you on this forum Stuart. RR
 
#34 ·
If this works the Service Bulletin I spoke about earlier will be shown I also found an earlier one but will not be able to do anything with that until next week. My scanner I is broke like me:laugh2:
K
Well, an interesting document K.

Whilst we know Meriden, in their confused state by the late '70's, did perhaps have the odd typo errors in some bulletins, I would hardly dismiss this document as being erroneous.

This bulletin would reflect the outcomes of a "perfect" condition charging circuit, and for these now "old" bikes, with aging parts, the document may not be an entirely reliable guide.

The final word is the trusty old multi-meter readings and a bit of simple maths to see just what the battery will tolerate as far as modified lighting is concerned. (something I must do BTW :)) RR
 
#37 ·
As I am an ignorant slug when it comes to dealin with negative ground items (my computer) Perhaps my GOOD FRIEND Stuart can post a link to the two threads (if he is done listening to the Stones for a few minutes).


Me I'm going over to Cops then its my bedtime. My little dog starts pullin off the blankets @ 4am


K
 
#36 · (Edited)
Lighting Up

I'm with you RR. None of the above nonsense has any effect on my efforts at trying to save my own skin. All motorcycles manufactured after 1983 out here (by Govt. decree) must have lights showing to the front when ridden on public roads. There was a bit of a hoo haa about that at the time, but common sense prevailed after a short time. Likewise, by Govt. decree all motorcyclists (and pillions) must wear an approved safety helmet. This move also met with huge disapproval. Now, when attending Rally's where thousands of Riders meet and greet sometimes the topics arise in respect to the 'good' ole days' when we sped around helmetless and lightless. The general consensus is 'there but by the grace of the motorcycle God we survived'. Even the most hard bitten of the old crew (of which I am one @ 63 years of age) would never revert back to those dark dim days.
 
#40 ·
Hi Viz Clothing

The idea was mooted here by Gummmmint, as it was in the Australian State of Victoria. Once the impractibility of the wearing of such equipment was explained too our lawmakers (and I presume those across the ditch) the idea was shelved as a compulsory measure. There are many Riders out here that do wear Hi Viz vests, it is great to have choice in some instances.
 
#41 ·
There are many Riders out here that do wear Hi Viz vests, it is great to have choice in some instances.
I cannot wait to get my fluro pink gear. You know, the ones we should make all outlaw bikies wear. :)

On a serious note. It was raining cats and dogs, and me on the old Trumpy (this is how I know that the Lucas (Prince of Light) handlebar switches will tolerate prolonged heavy rain) and my pal following on his Suzuki Bourlevard.

I could barely see the headlight, but the fluro rain gear could be seen clearly.

Yep, fluro gear is on its way fellas. In pretty pink for the outlaws and girls, and yellow for the rest of us. :) RR
 
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