I want a headlamp which looks original, and doesn’t need a little black triangle on the glass to be legal for the UK.
The pattern headlamp from the donor bike is in a pretty poor condition, the rim is very rusty, the reflector is poor quality, and the glass requires a black triangle.
The shell is quite nice though, being a near direct copy of an OEM Yamaha shell in dimensions and materials.
I bought a new pattern headlamp to see what kind of quality was available, and was disappointed, but i thought I could at least use the nice shiny rim with an OEM shell and a genuine Koito reflector/glass sourced from somewhere.
This was not to be, as the rim is fractionally larger diameter, and will not quite fit the OEM shell.
Additionally, the threads in the tabs do not line up with the holes in an OEM shell by about 2mm.
I embarked on a voyage of discovery to see how easy it would be to source alternative parts.
Consider the headlight in three parts…
1) Shell
2) Rim
3) Reflector/Glass
1) The shell is unique to RD250/350LC.
Over the years there have been many pattern headlights, and on some (the one I have for example), it is identical to the Yamaha/Koito one in all but the Yamaha embossing on the back.
The current pattern headlight, which seems to be the only one available from all sellers at £27 through to an outrageous £50, has a glossy shell made from brittle plastic which is thinner than the original plastic. The holes and clip are in slightly different places. there is no upper hole for the wires and connectors from clocks and indicators.
An original OEM rim should fit, perhaps with a bit of easing of the holes, but I have not tried that particular experiment yet.
2) The rim is unique to RD250/350LC
They are as rare as Unicorn doodoos in unblemished form, with good chrome and no roadrash.
The rim on the currently available pattern headlights is made of flimsier metal, and the internals are of a slightly different design. The clip, and the two mounting holes are not quite in the same places as the original rim, so it is not a straightforward swap into an original shell, without modifications to either rim or shell.
3) The Reflector/Glass differs from market to market.
European markets have E4 cast into the glass on the front, and have the number 997-16119 printed on the back of the reflector. They also have a metal dome mounted in front of the bulb, inside the unit.
I assume it dips to the right.
The UK, and other left hand drive markets, (Japan, Singapore etc.) has no E4 designation and has 997-16120.
i assume it dips to the left.
Right hand drive markets, (Canada, Rest of the world) has a similar glass front to the UK model, but has no pilot light. They have the number 997-16121.
I assume it dips to the Right.
There are a number of bike models which appear to use these Koito reflector/glass units.
I can confirm only three…
1) Yamaha RD250/350LC (Obviously)
2) Yamaha SRX400/600 (I bought one, the unit is identical, and is numbered 997-16120 for the UK model.)
3) Yamaha XS1100 (not sure which exact model). I bought one, and it arrived with a 997-16121 glass/reflector, so no pilot fitting, and presumably dips to the right… but it is one of these Koito units.
The rim and internal fixings of both the SRX600 and XS1100 are useless for the purposes of fitting into an OEM RD250LC shell without some major engineering effort.
For completeness, but unconfirmed, the rest of the list, which i assembled looking at pictures on t’intrnet is as follows.
Some of these bikes are US only models, so will have the US spec reflector/glass.
- YAMAHA SR400 SR500 SRX400 SRX600 XJ600N
- SRX600S 1986 600 SRX600 Street
- SRX600SCal 1986 600 SRX600 (Cal) Street
- XJ1100J 1982 1100 XJ1100 Street
- XJ750K 1983 750 XJ750 Maxim Street
- XS1100SF 1979 1100 XS1100S Street
- XS1100SG 1980 1100 XS1100S Street
- XS1100SH 1981 1100 XS1100S Street
- XS750F 1979 750 XS750 Street
- XS750SF 1979 750 XS750S Street
- XS850G 1980 850 XS850 Street
- XS850H 1981 850 XS850 Street
- XS850SG 1980 850 XS850S Street
- XS850SH 1981 850 XS850S Street
- XJ550(1981)
The freshly procured OEM Koito reflector/glass fits into the new shiny pattern rim, but the rim internal is slightly different, (because the pattern glass has a slightly different profile), requiring the excess mastic adhesive around the glass to be filed flat, and the rim itself to be eased out by approx. 0.5mm.
Now I have a rim, and glass, but the only shell it will fit into is the glossy pattern one.
i’m not yet ready to modify an increasingly rare OEM headlamp shell, so I’m back into Least Bad Option territory, (at least for the initial mechanical build)… which is to attempt some kind of cosmetic repair on the donor bike rim, (which DOES fit into an EOM shell).
Remember this?
so I’m going to have a crack at rubbing it back, priming with the rust eating bonda-primer, and trying out some “chrome” paint.
I’m not expecting miracles, but just enough to get me through this build while I contemplate a better solution.
At least I’ll have an OEM Koito glass and reflector in it.
The “chrome” paint looked really impressive in bright sunlight, but as more coats were added, the shine faded and it became merely “glossy silver”.
I finished it off with a few coats of clear lacquer, and it’s definitely not chrome… but acceptable as an interim solution.
When I can to assemble it all, I found that the freshly painted inner rim was NOT compatible with the OEM Koito glass. I should have anticipated this really, as the pattern glass is, and always has had a slightly different profile.
So I could file away the inner rim diameter to fit, as I had with the other pattern rim… but this was freshly painted, and I could only see disaster and disappointment ahead.
Instead I found an OEM crash damaged rim, from which I took the nearly OK chromed inner, and mounted that into the painted outer rim, and then the Koito glass to complete the assembly. which then went onto the bike. It all became a bit Frankenstein in the end!
Having completed the wiring and temporarily solved the headlamp issue, I slung some old bodywork onto it to give myself a sense of progress 🙂
