Headlight very dull on my 71 CT70H

CJ0566

New Member
Hello Everyone, I just restored a 1971 CT70H and the headlight is very dull. I had it checked by a mechanic and he said it's working correctly. He suggested changing the bike's 6 volt battery to a 12 volt battery and buying an LED headlight and wiring the new headlight directly to the 12 volt battery. I would like to know: 1) Is this a good idea? 2) If yes, what's the best and brightest headlight to buy? and 3) will this hurt the value of the bike? Any advice would be greatly appreciated. Thanks and have a great weekend!
 

b52bombardier1

Well-Known Member
Not a good idea, IMHO. Though the LED idea might be. My prediction is bad grounds, bad wiring into the headlight bucket. Dirty connections and broken copper strands inside of what looks like a good connection to the connector really affect a six volt electrical system. Start by experimenting with a temporary new wire to your headlight connector and clean up the grounds.

How old is your battery and its rectifier? It could be sapping the bike of juice but I'm a 90 CC Honda engine kind of person and my knowledge of the CT70 electrical system is kinda' thin. Yet, there is much the same between the two in that era.

Rick
 

darrel gunderson

Active Member
Hello Everyone, I just restored a 1971 CT70H and the headlight is very dull. I had it checked by a mechanic and he said it's working correctly. He suggested changing the bike's 6 volt battery to a 12 volt battery and buying an LED headlight and wiring the new headlight directly to the 12 volt battery. I would like to know: 1) Is this a good idea? 2) If yes, what's the best and brightest headlight to buy? and 3) will this hurt the value of the bike? Any advice would be greatly appreciated. Thanks and have a great weekend!
Pretty normal. I bet it gets brighter as you rev the engine ? Jon Pardu makes a really good LED headlight that is very bright but its not cheap ($80) I have one in my bike and it works ! Also has an led tail light bulb that is very bright and only like $8.00 Hes in FL.
 

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CJ0566

New Member
Not a good idea, IMHO. Though the LED idea might be. My prediction is bad grounds, bad wiring into the headlight bucket. Dirty connections and broken copper strands inside of what looks like a good connection to the connector really affect a six volt electrical system. Start by experimenting with a temporary new wire to your headlight connector and clean up the grounds.

How old is your battery and its rectifier? It could be sapping the bike of juice but I'm a 90 CC Honda engine kind of person and my knowledge of the CT70 electrical system is kinda' thin. Yet, there is much the same between the two in that era.

Rick
Tha
Not a good idea, IMHO. Though the LED idea might be. My prediction is bad grounds, bad wiring into the headlight bucket. Dirty connections and broken copper strands inside of what looks like a good connection to the connector really affect a six volt electrical system. Start by experimenting with a temporary new wire to your headlight connector and clean up the grounds.

How old is your battery and its rectifier? It could be sapping the bike of juice but I'm a 90 CC Honda engine kind of person and my knowledge of the CT70 electrical system is kinda' thin. Yet, there is much the same between the two in that era.

Ric

Not a good idea, IMHO. Though the LED idea might be. My prediction is bad grounds, bad wiring into the headlight bucket. Dirty connections and broken copper strands inside of what looks like a good connection to the connector really affect a six volt electrical system. Start by experimenting with a temporary new wire to your headlight connector and clean up the grounds.

How old is your battery and its rectifier? It could be sapping the bike of juice but I'm a 90 CC Honda engine kind of person and my knowledge of the CT70 electrical system is kinda' thin. Yet, there is much the same between the two in that era.

Rick
Thanks for the advice! The battery is new. I don't know what a recifier is so it must be old. I changed everything under the seat, the coil, battery, all wire harnesses, etc.
 

CJ0566

New Member
Pretty normal. I bet it gets brighter as you rev the engine ? Jon Pardu makes a really good LED headlight that is very bright but its not cheap ($80) I have one in my bike and it works ! Also has an led tail light bulb that is very bright and only like $8.00 Hes in FL.
You're correct. The headlight does get brighter when I rev the bike up. Thanks for the information. I'll check it out. My mechanic is from the Dominican Republic and he said they use a lot of these bikes over there and they all put in 12 volt batteries and wire the headlights directly to the battery to rectify the problem
 

CJ0566

New Member
And what about your coil that fires your spark plug , is it wired for 12 instead of 6 volts ?
No, the bike is set up for only 6 volts right now. Everything under the seat is brand new, coil, 6v battery, wire harnesses, rear break light switch, etc. The bike was completely apart a few weeks ago because I had it repainted. So I order all brand new electrical components from CHP and had them install the new components when they re-assembled the bike.
 

CJ0566

New Member
Did the headlight work better after all the electrical parts replaced?
It works about the same even with all the new electrical components. It is working correctly. I believe it's just the old technology that doesn't produce much light on these bikes. I probably just going to replace the headlight with an LED highlight (per mostly everyone's advice here) and leave the rest of the 6v electrical system alone.
 

JR86

Member
If you just had the bike repainted that can affect your grounds and hurt lighting quality.

Also it might be worth throwing a multimeter on your headlight wire and seeing how many volts you get when you're at idle and rev.

Might be time for a stator rebuild if you're not getting almost 7v at idle. The kit isn't terribly expensive and it can be rebuilt in an afternoon.

The headlight on these machines is not exceptional but it is certainly usable so if you don't feel yours is then theres def something wrong.
 

CJ0566

New Member
If you just had the bike repainted that can affect your grounds and hurt lighting quality.

Also it might be worth throwing a multimeter on your headlight wire and seeing how many volts you get when you're at idle and rev.

Might be time for a stator rebuild if you're not getting almost 7v at idle. The kit isn't terribly expensive and it can be rebuilt in an afternoon.

The headlight on these machines is not exceptional but it is certainly usable so if you don't feel yours is then theres def something wrong.
Thanks for the advice. I did check the voltage and it's working correctly. I think it's just old technology that I have to live with it. I sometimes ride on the street at night and it's very difficult to see. I also have bad eyesight which contributes to the problem. I've been considering attaching a rechargeable mountain bike headlight to the handlebars. Any suggestions regarding detachable headlights would be greatly appreciated, thanks!
 
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