H4 Bulb Headlight conversion on CB350 - not recommended

DrJ

Over 1,000 Posts
I have an H4 bulb conversion on my CB350 headlight with 60/55 watt rating. Only recently have I been doing longer night rides and realized it doesn't work well with the stock charging system. The original sealed beam unit is rated at 35/25 watts, much lower than the H4. The H4 draws too much power and depletes the battery faster than it can charge. First symptons are the signals and horn seizes to work. Then the idle starts slowing down. Luckily the bike will still run and the headlight still works even when the battery drains to 9.5 volts but the revs need to be kept up or it will stall. So for anyone considering switching to an H4, there is a charging kit that will work with an H4 that I may get.

http://www.ricksmotorsportelectrics.com/press2007/2007-09-11Classic_honda_kit.pdf
 
I put an H4 Conversion lap on my cb750 and it seems to work ok.
Although I had to wire in a headlight kill switch so that I could turn it off when starting the bike...
 
I've been using an H4 conversion in my kz650 for years with no problems, but the 2 55W driving lights I just installed are draining my battery if I ride at low rpms. At higher rpms/speeds, it seems to be ok.
 
You totally right, CB350s have some of the worst charging systems around. You might be able to pull it off if you replaced your tail/turn signals with LED lights. It probably even took some power from your coils.

Thanks for the heads up. Sometimes people advertise these bulbs as less power drawing, but I always thought it was a hoax. Good confirmation.
 
I know it doesn't give the most "classic" look, but I'd think about an HID conversion. www.sharphid.com has them for $60 or $65 and once lit they use an VERY small amount of power to maintain. They also produce less heat! most of the bluer tones would look silly on a cafe, but 3000k would be yellow and that would look killer.

If these were used I'd recommend using a switch on the lamps so they were only turned on while running, igniting them takes quite a bit of juice, once lit though it's all gravy.

Just a thought, but it may save you tossing that perfectly good H4 lamp.
 
H4's come in all sorts of wattage values.

Having a quiet moment at work, I did a quick check of the Tucker-Rocky catalog. They list a 35/35 H-4 bulb (P/N 20-0010) for $14.95. That'd still be an improvement over the stock CB350 bulb, which, if memory serves me correctly, was a chipmunk holding a candle in the headlight bucket.
 
Syke said:
H4's come in all sorts of wattage values.

Having a quiet moment at work, I did a quick check of the Tucker-Rocky catalog. They list a 35/35 H-4 bulb (P/N 20-0010) for $14.95. That'd still be an improvement over the stock CB350 bulb, which, if memory serves me correctly, was a chipmunk holding a candle in the headlight bucket.

Yup, I found one of those 35/35 bulbs at a scooter shop and it works great with the stock charging system. Much brighter and no more drained battery.
 
Mine ran for awhile with a 65/55 bulb but blew a fuse, harshing my mellow :mad:. I'm looking for a 35/35 tomorrow. What system would a 65/55 work with anyway?
 
Kev Nemo said:
Mine ran for awhile with a 65/55 bulb but blew a fuse, harshing my mellow :mad:. I'm looking for a 35/35 tomorrow. What system would a 65/55 work with anyway?

That's what I'm running in my '69 Bonneville. Yeah, Lucas electrics handles it with no problem.
 
DrJ said:
I have an H4 bulb conversion on my CB350 headlight with 60/55 watt rating. Only recently have I been doing longer night rides and realized it doesn't work well with the stock charging system. The original sealed beam unit is rated at 35/25 watts, much lower than the H4. The H4 draws too much power and depletes the battery faster than it can charge. First symptons are the signals and horn seizes to work. Then the idle starts slowing down. Luckily the bike will still run and the headlight still works even when the battery drains to 9.5 volts but the revs need to be kept up or it will stall. So for anyone considering switching to an H4, there is a charging kit that will work with an H4 that I may get.

http://www.ricksmotorsportelectrics.com/press2007/2007-09-11Classic_honda_kit.pdf

i'm running the rick's set-up (stator+rectifier/regulator) with a hondaman ignition on my cb350, although still stock headlight spec's. the conversion is something i want to do sooner than later.
i will say, the new charging system puts out over 12 volts at idle, and around 14.5 at 2000 rpm (checked when we first installed and fired the bike), and my battery doesn't need a trickle charger at all, using the e-start exclusively (lost the kicker on a BIG bump, no way to go back and get it off the road!). also, runs without stalling, although the carbs are fouling plugs, with stock coils.
 
I just replaced the sealed beam unit on my '66 Honda CB77 SuperHawk, and it's been great so far. I got the kit from Cycle Seductions (www.cycleseductions.com), and then found the 'low wattage' 35/35 bulb from Scooterworks. The only issue I had was all the extra braketry on the back of the unit which had to be removed - I think the kit was meant for a CB400f, but it's the same size (162mm) as the SuperHawk.
 
what about a HID? i've given thought to using one for non-cosmetic reasons, because although they need more power to turn on, their power use while running is lower than H4s.
 
Do the 350 and 360 have the same headlight?

If they do, I assume we need to upgrade the seal beam headlight to a bulb style HID, then get a lower wattage bulb, correct?

Can't you just get a higher watt sealed beam? Or does that end up with the same issue?
 
PHeller said:
Do the 350 and 360 have the same headlight?

I'd say yes.

PHeller said:
If they do, I assume we need to upgrade the seal beam headlight to a bulb style HID, then get a lower wattage bulb, correct?

Yes, unless the 360 has a stronger charging system than the 350 but I doubt it.

PHeller said:
Can't you just get a higher watt sealed beam? Or does that end up with the same issue?

I haven't seen a sealed-beam with the same wattage as an H4. But if there is one, yes you would run into the same charging problem. As already stated, a 35/35 scooter low wattage H4 works well with the 350/360 stock charging system.
 
the HID kits do require more juice for about 1-2 seconds at about 65 watts before they ignite and run at 35 watts. but you can run a relay kit off the batt to help with the extra juice. I dont know what the going rate is for the conversion with HID but, I have them for $45.00 +shipping for all DTT members any bulb temp and includes the headlamp
 
gpreciado said:
the HID kits do require more juice for about 1-2 seconds at about 65 watts before they ignite and run at 35 watts. but you can run a relay kit off the batt to help with the extra juice. I dont know what the going rate is for the conversion with HID but, I have them for $45.00 +shipping for all DTT members any bulb temp and includes the headlamp

Got a link to this?

I have been thinking about doing it to one of my bikes to help the charging system out a bit.
 
Syke said:
H4's come in all sorts of wattage values.

Having a quiet moment at work, I did a quick check of the Tucker-Rocky catalog. They list a 35/35 H-4 bulb (P/N 20-0010) for $14.95. That'd still be an improvement over the stock CB350 bulb, which, if memory serves me correctly, was a chipmunk holding a candle in the headlight bucket.

I thought it was a pair of copulating glow worms? ;D
I've mentioned the 35/35 bulb several times, pair of them were standard in early FZR1000
 
I've seen Amish buggies shedding more light.

But anyways, Dime City sells 35/35w b4 bulbs.
 
My XS650 project bike has been running well with a H4 conversion using 60/55 bulbs...so far...and there have been a few long night rides in the mix...FWIW..
 
Parts Unlimited are listing a 45/45 H4 bulb, don't know price but it's the first time I've seen them.
 
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