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24K views 26 replies 15 participants last post by  Boverboy 
#1 ·
As everyone knows (and I'm learning) the old Honda twins are not a motorcycle, they are a commitment. They are not a hobby, they are a lifestyle. From the aggravation of trying to figure out the d**n synchronization of the carbs to sniffing out decent replacement parts, they aren't just plug-n-play bikes.

This past summer I spent most of my time working on fabricating some new resonators/mufflers for my bike. After I got them welded up and installed, I spent the early fall getting the carbs tuned and synced. By the time it was running good there wasn't much time to ride but I took advantage of the opportunities and have enjoyed the way that old girl climbs up to 60 REAL fast.....and then kind of hangs out at the mile a minute mark.

With a good tailwind she'll goosebump me to the 70 mark but 60-65 is where she likes to camp. I'm okay with that for now.

Anyway, with a few hundred miles on the odometer the headlight died on me. So it was back in the barn for the lady until I sniffed out another headlight.

A bit of hunting revealed that I could spend a small fortune getting an OEM (used) headlight or a larger fortune upgrading to a replacement system. I chose neither.

As most are probably aware, the "sealed beam" headlight (at least on my K6) isn't really a sealed beam. They are a reflector and lens built around a miserable bulb and soldered together at the ass end.

In the past, as I was doing a little rattle can rebuild on her, I figured I could somehow use the housing and replace the bulb with something a little less......weak, but I didn't really think much about it ( I didn't want to ruin the only headlight I had) until the headlight finally quit. When it burned out, I needed to do something. A quick search of this forum showed me a thread about using an H4 bulb in an existing housing

H4 Headlamp

HerrDeacon inspired me with his use of Quick Steel and after some thought, I took a shot at it myself. I decided to make this thread to help anyone else who wants to replace their headlight without spending a paycheck and keeping the vintage look of the original lens.

I'll do it one post at a time because I took a bunch of pictures and I always seem to get "signed out" when I'm trying to post anything of any length.
 
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#2 ·
The first thing I did (after removing the headlight from the bucket) was to use a hacksaw to carefully cut around the bulb base at the point where the neck of the reflector ends.

Coping saw Cookware and bakeware Pizza cutter


The bulb globe fell inside the housing and the assend with the soldered connections came off easily. I cleaned up the connection site with a fine file and using a screwdriver, I broke up the old globe inside the housing. Once broken up, the bulb pieces were easily shaken out leaving a nice clean housing ready to use.

Finger Hand
Cymbal Auto part Wood Metal
Cookware and bakeware
 
#16 ·
The first thing I did (after removing the headlight from the bucket) was to use a hacksaw to carefully cut around the bulb base at the point where the neck of the reflector ends.

View attachment 49269

The bulb globe fell inside the housing and the assend with the soldered connections came off easily. I cleaned up the connection site with a fine file and using a screwdriver, I broke up the old globe inside the housing. Once broken up, the bulb pieces were easily shaken out leaving a nice clean housing ready to use.

View attachment 49270 View attachment 49272 View attachment 49271

First off, great article. My headlight actually makes a "cross-like" shape that doesn't provide me with any light. After reading this article I was left with the question of how to safely remove the headlight from the chrome bucket?
 
#3 ·
The next step was to retrofit the housing to accept a new halogen bulb.

I had seen some other retrofits that worked, but left something to be desired in the looks department. Also, I wanted something that would make it easy to replace the bulb when it burned out. I decided I wanted to use a threaded cap of some sort so I could simply unscrew the old burned out bulb and screw in a new one.

So I bought a tube of JB Weld - Steel Stick at Home Depot ($5.77) and an 1-1/4" electrical conduit busing at Ace Hardware ($1.04). They probably have the bushings at Home Depot too but I was at Ace Hardware and I like Ace so....

All told (not including the bulb) it was less than $10 to do this modification.
Product


In the center of the picture is a "washer" I cut out of some 24 gauge aluminum trim coil. I cut it at 1-1/2" in diameter with a 3/4" hole centered in it.
 
#5 · (Edited)
Kneading the entire tube of JB Weld - Steel Stick, I made a donut around the hole in the back of the housing.
Copper Metal


I used a short length of steel tube to stick in the housing to keep the putty from overlapping the hole but I don't think that was necessary.

After I formed the donut of putty, I sprayed the plastic bushing, the aluminum "washer" and the lightbulb with silicone spray so the steel putty would not stick to any of them.

Put the "washer" and bulb (now slick with silicone spray) together

Product Smoke detector Ceiling Circle


and press the entire assembly down into the housing like it would be when installed. Pressing the whole thing down into the putty will squeeze the steel putty out to the side and fill all the voids in the light/bushing assembly. After the assembly has seated against the housing, you can cut away the excess putty that has squeezed out the sides. You can see the silcone squeezing out of the assembly between the "washer" and the bushing.
Auto part Circle Rotor Machine Wheel
 
#6 ·
Once you've pressed the assembly over the putty and cut away the excess, "loosen" the bushing by unscrewing it just a little to make sure it isn't stuck in place. It should look like this.

Copper Metal Auto part


I didn't wait long to unscrew the bushing on my mold. I got a little nervous and probably over reacted but I was afraid I'd let the bulb bond in the steel putty and never get it apart without wrecking it.

But when I unscrewed the bushing, the bulb came out pretty easily. I had not used enough silicone and the steel putty stuck to a couple parts so it wasn't the neatest extraction possible. Having learned that lesson I say, use plenty of silicone spray, you can always clean it off later.

After I unscrewed the bushing and took out the bulb, this is what it looked like. A nicely formed neck with well defined threads.

Auto part Metal


The bushing screwed on and off beautifully and the bulb inserted and seated nicely. All in all it was a great success. After that it was an easy matter to.......
 
#7 ·
Paint the housing
Blue


I used VHT Satin Black Epoxy
Tire Automotive tire Automotive wheel system Spray

Despite wiping the housing down with mineral spirits I still had some minor fish eye but since it's always hidden in the light bucket, I didn't worry too much about that.

Light Auto part Automotive lighting Circle Ceiling


Solder up new connectors on the old wires.
Cable Wire Electrical connector Technology Electronics accessory


Put on the rubber boot (mainly for looks and so I wouldn't lose it because there's nothing for it to fasten to).....
Wire Electrical wiring Cable Hand Electronic device


Then make sure it works.....

Automotive lighting Red Light Headlamp Auto part
 
#8 ·
Since SC requires that all motorcycles operate with high beams on all the time, and since the old Honda alternator struggles to make 120 watts output, I decided to forgo using an H4 bulb that has the dual elements. It was very hard for me to find an H4 bulb that was the 35W / 35W configuration. All the H4 bulbs in the auto parts stores are 55W / 60W. I was afraid that that would be too much for the weak alternator output.

So I opted to use the single element H7 bulb which is a 55W bulb. You can find these for $9 - $28 in the auto parts stores. The really Ultra White ones put out a nice light and it's as much for visibility as it is for nocturnal navigation.

I labeled and taped the low beam wire inside the bucket just in case I go senile and can't remember what I did. Also that way the next owner (if there is one) won't cuss the P.O. for a stupid trick.

Electrical wiring Wire Cable Electrical supply Technology


Now a final assembly....

Light Audio equipment Automotive lighting Circle Gas


Install and......
 
#11 ·
Wow! Kind words HerrDeacon. Thank you.

I found one 35/35 watt H4 at the PowerSports shop locally that looked like it had hung on the wall for 20 years. I figured if it was that hard to find on the shelf it might be better to use a common alternative.
 
#13 ·
Thanks bilbikek411.

Having been in the remodeling business for years (and siding my own home as well) I had the better part of an aluminum trim coil in the shed. But any light gauge metal would work, even salvaging a soup can and flattening it out I guess.
 
#15 ·
35/35 are real easy to find, but, you have to go to a scooter/moped shop. They are commonly fitted on Chinese scooters
 
#17 ·
Has anyone installed an H4 bulb? I think the H4 bulb is bigger than the H7 bulb. I bought an H4 35/35w bulb and then bought an 1 1/4 bushing. The bushing was way to small. I bought an 1 1/2 bushing and it might work if I trim most of the 3 tabs off of the bulb. The glass part of the bulb fits through the hole but the base doesn't. I don't think it is in far enough for the filaments to line up with the reflector properly. I would need to open the hole up more than the diameter of the neck. Would that mess up the reflector? I have been reading and it looks like I need to orient the bulb with the low beam reflector on the bottom facing up? I just want to make sure before I mess anything up.
 
#20 · (Edited)
Has anyone installed an H4 bulb? I think the H4 bulb is bigger than the H7 bulb. I bought an H4 35/35w bulb and then bought an 1 1/4 bushing. The bushing was way to small. I bought an 1 1/2 bushing and it might work if I trim most of the 3 tabs off of the bulb. .......... I have been reading and it looks like I need to orient the bulb with the low beam reflector on the bottom facing up? I just want to make sure before I mess anything up.
Trimming the tabs off the H4 worked but I chose not to use it.

After riding at night with this setup I am not recommending it for night riding. Maybe with some adjustments I can get an adequate beam but it's a white knuckler for sure and probably not a good idea.

Final word? Works great for daytime riding to meet requirements and maintain visibility and it's a neat fix.
 
#18 ·
For those interested in a H4 headlight with a straight forward install, I recommend the EMGO 6 1/4" Headlight Assembly. I ended up buying mine from BikeBandit. The assembly comes with the bucket, headlight lens and H4 bulb. However, I replaced the H4 bulb with a 35w/35w as previously mentioned to do in this thread. The bucket uses the same bolt size 10x1.25 and I was able to pack in all the wiring. I've yet to have it ride it at night yet but so far to the naked eye it looks brighter.
 
#21 ·
sorry to bring up an old post but since it's a sticky, I don't mind so much lol.

anyways, long time reader, first time poster, blah blah. awesome write up. your and HerrDeacon's posts inspired me to tackle the upgrade myself instead of just buying a replacement.

I'm curious if you guys have had the same issue I have at all, or any input at least as to what it could be. I tied in to the wiring directly on my 1972 CL 175, bought a wired H4 socket, hooked it up to the stock wiring g using bullet connectors, even tried using the wiring from the original blown sealed bulb to keep the ground to the ring, but once I hooked up the H4 socket I lost front blinkers entirely. and my backs are hazard flashing. the low and high beam work now, but no blinkers is kinda sketchy in my populated area.

any type of insight would be much appreciated.
 
#23 · (Edited)
You shouldn't have any issues fitting a H4 bulb as long as you have a 12v system (I had some 6v H4's but don't remember where I got them?)
If you've 'lost' any lights you must have disconnected something or flexed a wire and it broke. The front indicators are light blue and the orange wires. Anything green (or black with a green tube for the indicators) is a ground lead. I've seen indicator grounds plugged into 12v live many times, the rubber mounted fork ears prevented fuse blowing though (often the indicator bodied will also be grounded) You'll need to get back in there and check all the wires are connected properly
 
#24 · (Edited)
Sometimes an Internet DIY solution really works. My project, "The 100 Dollar Honda", CA175 K0 is going to use a CL175 K0 headlight shell so that I can use the speedo with the 5 speed shift indicated on it and that meant using one of the old style headlight rims. I'm also staying with the original CA175 6 volt electrics and that made finding a modern headlight reflector with replaceable bulb a real problem. Luckily I saw this mod on the forum and it worked a treat so that I can either use a standard H4 6 volt 35/35W bulb or a 6 volt 12W LED conversion bulb. I used a Dremel cut disc to quickly remove the original bad bulb in the eBay beam that I bought and opened the hole up to 25mm so that the H4 bulb would fit in. With the larger sized plumbing nut for the trimmed H4, I found that a steering stem washer fit perfectly to help seal the bulb. The nut needed to be trimmed with a hobby knife at the lip where the washer fit so there would be enough threads.

I had just a slight problem with some of the Steel Stick putty going into the hole and the H4 bulb sticking to it. If I did it again I would smear a bit of dielectric grease on the bulb base as well as spray it with silicone. The excess putty that went into the reflector hole around the bulb base was easy to trim with a knife. Still it turned out great.
 
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