TOPIC:

I have bought this led h4 bulb ,but not sure if its safe to install that and if it even fits or will work ?

Assuming you don't have a US sealed beam unit yes it'll fit and work.
However, your high beam idiot light might function differently and the original lens spread pattern is made for an incandescent bulb and leds emit light differently so may blind on coming vehicles. 
In the UK the police can confiscate  vehicles with led bulbs fitted to incandescent headlights. 
They have that power but I've never heard of it happening. Your choice. 
You can legally replace incandescent with halogen bulbs but not leds unless the lens is manufactured for led. 

Rolf the below is a high performance "white light" bulb that is still road legal. I fitted these to my wife's car at the start of the winter and they are significantly better than the standard H4

 

It only uses 20W so it will be perfectly fine. except for what was said about the high beam, but even then that may not be an issue.  

Zymurgy's First Law of Evolving Systems Dynamics: Once you open a can of worms, the only way to re-can them is to use a larger can.

When we upgrade the forum software, can we get popcorn & can-o'-worms emojies?  Please?

LED headlight threads are beginning to resemble motor oil threads.  Often we see LED from fleaBay claiming ten-seventeen-eighthundred gazillion Chineseium lumens.  At least there are some verifiable facts about this Philips LED vs incandescent debate in the Philips catalog.

Lenses & reflectors are designed as a system to focus light into a specific beam pattern from an emitted source of expected size & position.  In H4 halogen bulbs that is the filament suspended in space, emitting 360 deg.  LED's are different emitters in both size, orientation, emitting directions and position  within the lens / reflector system.

Motorcycle headlight beam patterns are somewhat different than those of dual headlight four-wheel vehicles.  DOT-legal sealed beam & H4 motorcycle headlights will generally have "MOTORCYCLE' cast into the lens glass.

The 2023 / 2024 Philips catalog is linked below:
www.philips.com/c-dam/b2c/en_GB/marketin...EN-EN_EMEA_23-24.pdf

Philips own catalog lists the Ultinon Access  bulb in the 'LED off-road' section per page 3.

On pg.8 they list 'LED road-legal' bulbs.  Note the beam shape & striping on the paved roadway.  At the bottom left of pg.8 there's a blue road icon with a check mark, indicating road legal.

On pg.18 we see the Ultinon Access bulb in the automotive section.  Note the beam shape & no striping on the dirt road (off road).  Bottom left of the page is the roadway icon grayed out with an 'x', as may not be road legal.  User is responsible for ensuring legality in their jurisdiction.  Same things on pg. 24 specific to the Ultinon.

On pg.76 we see the Philips motorcycle bulbs, all of which appear to be halogen.  Note the different beam patterns vs automotive beams noted above.  Also, note the striped roadways (on-road).

Will the Ultinon bulb 'fit'? Probably.  Will it 'work'?  It probably will illuminate.  Will glare from what may well be a resulting poorly-focused & incorrectly-shaped beam pattern blind oncoming drivers?  Very possible.  Will said  beam pattern result in fewer lumens on target down the road where it's needed?  Very likely.

Complete LED headlight assemblies are available for motorcycles as direct swap replacements.  They ensure lighting is appropriate for the application.

Why do you want to change to an LED?

Good Ridin'
slmjim & Z1BEBE

(slmjim shouts, "Hey babe, where's that really big worm can...?")



 

Completely agree, the bulb I suggested is simply a more efficient "halogen" bulb which omits "white light"

I've put Sylvania SilverStar bulbs in several motorcycles using lesser H4 bulbs.  They are a nice improvement, and not overly expensive.

Alternate is a Truck-lite, which I've heard are great.  They are quite expensive these days, though.  More than double a couple years back.
 

Rolf1976_KZ900 wrote:

I have bought this led h4 bulb ,but not sure if its safe to install that and if it even fits or will work ?

I had one like this but the vibration killed it. 
 

Okay thank you for lots of info guys. I have been in the garage doing some work on the bike and installed the bulb to test it. The reason i bought it was that i have very little light coming out of the headlight it is yellow and dim.I guess it is a combination of old wiring and maybe old bulb to.
I was in a store yesterday to buy some other things and dicovered the led h4 bulb and thinked.. okay so now its possible to just install a led h4 bulb with no other mods so i bought the bulb.
On my fj1200 that also had weak headlight i installed a headlight relay kit and installed a ceramic bulbholder and h4100w bulb. That made a big difference in light power. I rememer reading a lot of test what was the best H4 bulb back in 2020 and it was the one in picture below. I have been thinking of doing the same on the kwaka and that would also give a relaymod for the coils in the same time because the light enchanchement kit / relays ifs for cars and have 2 outputs one for each headlight.One problem on the kawa is that the bulb sits inside the bucket and a stronger bulb gets to hot
I dont like so many non oem wiring mods on the kz900 so i think just changing the bulb for a LED is maybe better.
I changed the bulb today in the garage and it was i very big difference in power and brightness on the wall infront of bike.
I will ride with a little and see if the oncoming cars blink their lights to tell me they are blinded. It has both low and highbeam and when looking at the wall in the garage it made a sharp line same height as the H4 halogen .Will do some driving and see if the cars will react to the light.

 

Rolf I would advise against the 100w bulb option, that would draw 9 amps + 4-6 amps for your coils + the rest of the electrical system. I couldn't see a spec in the manual but I guess the total output of the charging system is probably around 18 amps so you will be running a 40 year old generator
"flat out" all the time the headlight is on (even the low beam at 80w is drawing 7 amps) the stock headlamp at 60w draws around 5 amps !!

Wookie58 wrote:

Rolf I would advise against the 100w bulb option, that would draw 9 amps + 4-6 amps for your coils + the rest of the electrical system. I couldn't see a spec in the manual but I guess the total output of the charging system is probably around 18 amps so you will be running a 40 year old generator
"flat out" all the time the headlight is on (even the low beam at 80w is drawing 7 amps) the stock headlamp at 60w draws around 5 amps !!



 

Thanks for adwice wookie
Yes i wont be using a 100w bulb if i install the relay mod on the kawasaki.The 100w get extremely hot and may melt the wiring inside the
headlamp bucket .so on the kawa i will use a bulb like you suggested if i do that mod. On the FJ the setup using a 100/80w bulb has worked fine for 4 years.The reflector does not get damaged either ,but it is no wiring near the bulb and more ventilation in the fj headlight.

And i forgot to warn other temted to install a 100w bulb without doing a relay mod .What happens the is that the wiring can catch on fire if the fuse dont burn out at least the wires get very hot if they are not big enough

I would guess the FJ being a later bike probably also has a higher output generator so is better able to handle the load