Adjusting headlight on 1999 R1100RT

[Hoorenga]

I was doing a pre trip check out on my 1999 R1100RT and found an odd bolt behind the headlight with a plastic head on it. I should have left well enough alone but I screwed it all the way out and then screwed it back in trying to figure it out. Unfortunately it left my headlight pointing up into the tree tops. Fortunately I only did about one hour of night riding on my trip and had my partner take the lead so it wasn't a problem. I have tried messing with it some more but nothing seems to have any effect on where the lamp points. I looked in the small owners manual that comes with the bike and it says to take it to the dealer to have the headlight aimed but they always say that for anything beyond putting air in the tires. Has anyone had any luck aiming their own headlamp? It is further complicated by the fact that the bike is an RT and the headlight is buried in the fearing and I practically have to break my wrists to get to it.

Doug

[PGlaves]

I was doing a pre trip check out on my 1999 R1100RT and found an odd bolt behind the headlight with a plastic head on it. I should have left well enough alone but I screwed it all the way out and then screwed it back in trying to figure it out. Unfortunately it left my headlight pointing up into the tree tops. Fortunately I only did about one hour of night riding on my trip and had my partner take the lead so it wasn't a problem. I have tried messing with it some more but nothing seems to have any effect on where the lamp points. I looked in the small owners manual that comes with the bike and it says to take it to the dealer to have the headlight aimed but they always say that for anything beyond putting air in the tires. Has anyone had any luck aiming their own headlamp? It is further complicated by the fact that the bike is an RT and the headlight is buried in the fearing and I practically have to break my wrists to get to it.

Doug

Position the motorcycle on a flat level surface (garage floor) so the headlight lens is 17 feet from a flat vertical surface (wall). With somebody sitting on the bike, wheels on the floor, measure the distance from the floor to the center of the headlight lens.

Then mark a horizontal line on the wall 2 inches lower than the height of the center of the lens.

Aim the light, again with rider astride, so that the flat top sharp cuttoff of the low beam matches that line.

Your headlight will then be aimed correctly. You can fudge it up or down about a quarter of an inch but 2" at 17 feet is spec!!

[MotorradMike]

I think he needs more than the spec. Paul.
It sounds like his adjustment screw isn't adjusting the light. I'd give him the answer if I knew what the answer was!

Does something fall off inside if you take the screw too far out?

[PGlaves]

Yes, something does fall out if it is screwed all the way out. And it isn't pretty from there on out. I've not been into an RT but will guess it is very similar to an RS - where I unfortunately have been.

What falls out is a spring. The threaded rod on the adjusting knob goes through a spring and threads into a cylindrical barrel. The rod goes through the center of the spring and the spring tensions the light by pushing forward. It may be possible for the barrel to fall out too.

It is nearly impossible (without blind dumb luck) to get to it; compress the spring; stick the threaded rod through the spring; and get the threads to align with the round barrel which is designed to pivot when the headlight is adjusted.

On the RS I couldn't do it through the little hole through which I could see it, so needed to remove fairing chunks to get it done. I don't remeber everything that had to come off - and the RT fairing is different too. Suffice it to say that if he in fact did unscrew the threaded rod all the way he has a large task ahead to regain a functional headlight.

Bummer!!

P.S. The incident with the RS headlight happened on Voni's R1100RS somehow, while she was riding between Missoula, MT and Primm, NV during Leg 1 of the 2003 Iron Butt Rally. Fine in Missoula, flopping around by Primm, untouched by human hands in the interim. Which explains why I wasn't my normal witty personable self with parts strewn around the parking garage at the hotel in Primm while cheery folks kept wandering by wanting to know, "How's it going?"

Added: And as it turned out that was the only significant problem we had during that rally on either of our bikes, both of which started the rally with over 300,000 miles on them.

[Hoorenga]

I was afraid of that. Now my next question is, how do you get the upper, front part of the fearing off? I had the windshield off and all of the screws removed around the edge that I could find, even the ones under the break away mirrors and it would not budge.

Doug

[cheesewhiz]

Do I need to re-aim my headlight after replacing the bulb?

:dunno

Thanks in advance. :thumb

[Hoorenga]

The larger reflective housing that the bulb screws into is independently mounted. The bulb screws into the back and should not effect the aim of your headlight. The adjustment is done to the housing that the bulb screws into not the bulb itself. I suppose it is possible that the bulb could be misaligned but it is still the reflective housing that aims the light and it is solidly mounted and wouldn't easily be knocked out of adjustment. I took my bike out on a level road and aimed it simply by judging what worked best for me.

Doug

[cruisin]

. . . . I took my bike out on a level road and aimed it simply by judging what worked best for me.

I guess this means you figured out how to get everything back in place. Care to share some details of the experience / procedure just in case some of us other do it your-selfers screw up at some point?

[Hoorenga]

Yeah, what ever you do, DON'T SCREW THE ADJUSTMENT BOLT ALL OF THE WAY OUT! The headlight is a factory sealed unit ($250) with mechanical parts for adjusting it located inside. Once you screw the adjusting bolt all of the way out, the internal parts fall away and unless your hands are the size of a raccoon's you are really screwed. The only way to get at the loose parts is to remove both the lower and upper fairings (both sides) and remove the headlight. The headlight housing is not designed to be disassembled but it can be done if you are patient. The main housing is a plastic case with a glass lens glued to the front. Fortunately the bonding agent remains somewhat elastic and can be loosened by working a thin knife very carefully around the edge. It took me about an hour of fiddling to work it loose, nearly stabbed myself in the leg and hand several times. Once the lens was off it was a simple task to re assemble the internal parts that had fallen out of place. The washers turned out to be mounting washers for the external bolts on the headlight. How the heck the got mixed in with the inner works I'll never know. I re seated the lens using the original caulk as well as giving it a coat of silicon around the outside edge for extra measure. Works great!

Doug