Author Topic: H4 60/55w light?  (Read 2194 times)

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Offline mcswny

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H4 60/55w light?
« on: June 16, 2014, 07:13:29 PM »
Looking to upgrade my tired headlight (plus it got pretty dinged up when my bike got backed into, not sure how though?)

My question is could I run a H4 60/55w headlamp with stock electronics on a 750K2? Do I NEED Hondaman's relay or will it not work regardless as from what I can tell stock wattage is 40/50w?
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline mcswny

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Re: H4 60/55w light?
« Reply #1 on: June 16, 2014, 07:18:24 PM »
Here's the wattage of the headlamp I'm currently running, pretty low.
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline Bodi

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Re: H4 60/55w light?
« Reply #2 on: June 16, 2014, 07:52:53 PM »
What bike?
A 750 should handle the 55/65 bulb OK, the relay would be best to get the extra current out of the harness though. Smaller bikes, I would get the headlight but replace the bulb with a 35/35W one (common in scooters, easy to find). This will still be amazingly brighter than your Stanley sealed beam.

Offline mcswny

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Re: H4 60/55w light?
« Reply #3 on: June 16, 2014, 07:55:46 PM »

What bike?
A 750 should handle the 55/65 bulb OK, the relay would be best to get the extra current out of the harness though. Smaller bikes, I would get the headlight but replace the bulb with a 35/35W one (common in scooters, easy to find). This will still be amazingly brighter than your Stanley sealed beam.

Yeah bodi, it's a 750K2. Good to know! Thanks. Maybe I'll grab the headlight now and upgrade to the relay next or vice versa.
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline LesterPiglet

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Re: H4 60/55w light?
« Reply #4 on: June 17, 2014, 02:48:27 AM »
I've been running an H4 on my 550 for years without a problem so the 750 shouldn't either.
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Offline mcswny

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Re: H4 60/55w light?
« Reply #5 on: June 17, 2014, 04:20:57 AM »

I've been running an H4 on my 550 for years without a problem so the 750 shouldn't either.

Thanks Lester!
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline vames

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Re: H4 60/55w light?
« Reply #6 on: June 17, 2014, 04:42:33 AM »
What bike?
A 750 should handle the 55/65 bulb OK, the relay would be best to get the extra current out of the harness though. Smaller bikes, I would get the headlight but replace the bulb with a 35/35W one (common in scooters, easy to find). This will still be amazingly brighter than your Stanley sealed beam.

Agree. If you're replacing a tired old sealed beam with a new H4 reflector and bulb, it's going to naturally be much much brighter even at the same energy consumption. You don't necessarily have to increase wattage to get the result you want. I've got a 35/35 bulb in the 400f and it's like night and day versus the 30-year old sealed beam that was in there. And my 2 cents: a relay is a great idea to reroute the current around the old switches and straight to the light.

Offline mcswny

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Re: H4 60/55w light?
« Reply #7 on: June 17, 2014, 05:21:54 AM »
What bike?
A 750 should handle the 55/65 bulb OK, the relay would be best to get the extra current out of the harness though. Smaller bikes, I would get the headlight but replace the bulb with a 35/35W one (common in scooters, easy to find). This will still be amazingly brighter than your Stanley sealed beam.

Agree. If you're replacing a tired old sealed beam with a new H4 reflector and bulb, it's going to naturally be much much brighter even at the same energy consumption. You don't necessarily have to increase wattage to get the result you want. I've got a 35/35 bulb in the 400f and it's like night and day versus the 30-year old sealed beam that was in there. And my 2 cents: a relay is a great idea to reroute the current around the old switches and straight to the light.

I've been reading a bunch about the relay switch and how you're bypassing the handlebar switches. My only questions is if your routing straight from the battery and are you in an "always on state" or does the handlebar switch still work in terms of hi/low/off?
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline Bodi

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Re: H4 60/55w light?
« Reply #8 on: June 17, 2014, 07:19:43 AM »
the hi-lo switch is unchanged. The relay bypasses the ignition switch and lots of other stuff in the harness and is controlled by the headlight on/off switch (if you have one!). Functionally it is identical, with some difference under the "hood".

Offline mcswny

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Re: H4 60/55w light?
« Reply #9 on: June 17, 2014, 07:40:35 AM »
the hi-lo switch is unchanged. The relay bypasses the ignition switch and lots of other stuff in the harness and is controlled by the headlight on/off switch (if you have one!). Functionally it is identical, with some difference under the "hood".

Exactly the answer i was looking for!

I believe I heard HM talks about this in his book, I'll read up on it more tonight.

Thanks so much guys!
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline Duanob

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Re: H4 60/55w light?
« Reply #10 on: June 17, 2014, 09:34:04 AM »
I run a 35/35W H4 as well. It's plenty good enough to be seen. If you ride pitch black country roads you might consider the next step up 55/65W but it shouldn't tax your electrical system if it's good order. If you go with a MC lens like a Bosch then it's easy enough to just swap out H4 bulbs.
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Offline mcswny

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Re: H4 60/55w light?
« Reply #11 on: June 17, 2014, 09:43:13 AM »
I run a 35/35W H4 as well. It's plenty good enough to be seen. If you ride pitch black country roads you might consider the next step up 55/65W but it shouldn't tax your electrical system if it's good order. If you go with a MC lens like a Bosch then it's easy enough to just swap out H4 bulbs.

More good information, thank you!
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline vames

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Re: H4 60/55w light?
« Reply #12 on: June 17, 2014, 11:15:15 AM »
the hi-lo switch is unchanged. The relay bypasses the ignition switch and lots of other stuff in the harness and is controlled by the headlight on/off switch (if you have one!). Functionally it is identical, with some difference under the "hood".

Not true from my own design. You need two relays -- one for high one for low. The blue and white wires that currently go to the headlight are then used to each "trip" one of the relays (which requires very little current from the handlebar switch). Once one of them is tripped, it then connects a wire that comes straight from the battery directly to the headlight.

(relays are so simple, but writing about them in words seems incredibly complicated).

Just order the kit from Hondaman -- he makes it so that you can just plug it in to your harness and be done with it.....

http://sohc4shop.com/catalog/product_info.php?cPath=23&products_id=46



Offline HondaMan

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Re: H4 60/55w light?
« Reply #13 on: June 17, 2014, 11:23:04 AM »
The bikes with the OFF-LO-HI switch will slowly warp the plastic contact supports when using the 60/55W H4 (that's what I have in my 750K2). It takes about 5 years of my riding time to do it. I make the Dual Relay Kit for those bikes.

The bikes with the ON-OFF on the right and the LO/HI on the left only need the cheaper single-relay kit.

The bikes with only the Lo-Hi switch on the left need the Start Button Saver relay kit to save the Start button from self-destructing with the higher-wattage bulb.

In tests I did years ago (1990s era), the 40/45w H4 bulbs were slightly brighter and further down the road than the stock Stanley bulbs in the 750. The next step up in H4 is the 60/55w bulb, which then started attacking my headlight switch(es). When I could not buy a new one (in 2002) I created the dual-relay kit, sort of from need: I like the 60/55w bulb at night for my older-than-my-750 eyes. ;)
See SOHC4shop@gmail.com for info about the gadgets I make for these bikes.

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Offline mcswny

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Re: H4 60/55w light?
« Reply #14 on: June 17, 2014, 11:35:11 AM »

The bikes with the OFF-LO-HI switch will slowly warp the plastic contact supports when using the 60/55W H4 (that's what I have in my 750K2). It takes about 5 years of my riding time to do it. I make the Dual Relay Kit for those bikes.

The bikes with the ON-OFF on the right and the LO/HI on the left only need the cheaper single-relay kit.

The bikes with only the Lo-Hi switch on the left need the Start Button Saver relay kit to save the Start button from self-destructing with the higher-wattage bulb.

In tests I did years ago (1990s era), the 40/45w H4 bulbs were slightly brighter and further down the road than the stock Stanley bulbs in the 750. The next step up in H4 is the 60/55w bulb, which then started attacking my headlight switch(es). When I could not buy a new one (in 2002) I created the dual-relay kit, sort of from need: I like the 60/55w bulb at night for my older-than-my-750 eyes. ;)

Thanks Hondaman! I'll probably just be putting an order for the relay soon. Thanks for the info!
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80

Offline vames

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Re: H4 60/55w light?
« Reply #15 on: June 17, 2014, 02:51:29 PM »
Certainly not going to argue with Hondaman, but here's how I did mine. I just basically spliced two relays in just before the headlight plug. Works great and makes it so that very little current goes through any of the handlebar switches.


Offline mcswny

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Re: H4 60/55w light?
« Reply #16 on: June 17, 2014, 03:44:56 PM »
Certainly not going to argue with Hondaman, but here's how I did mine. I just basically spliced two relays in just before the headlight plug. Works great and makes it so that very little current goes through any of the handlebar switches.

Thanks Vames!
1972 CB750 K2
1997 XR600r (street legal)
1975 XL250
198 XR80