Technical Tips – Page 11 – Airheads Beemer Club

Airhead Lift

For a number of routine and repeated maintenance jobs, you need to raise the bike. Here is a classic cheap Airhead approach to getting the bike high enough into the air to easily remove a rear tire, work on forks, etc. and to do it alone.

Basically, we are going to put some blocks under each foot of the centerstand, tilting side to side to get the blocks underneath. But centerstands and bike geometries vary some and so you might wish to experiment a bit before rushing ahead to cut all the lift-blocks.

The remainder of this article is only available for Airheads Beemer Club members. Please login or purchase a membership here to join the Airheads Beemer Club, after which you will enjoy access this article and all members only content of the ABC web site.

Headlamp Cutout Switch

This is simple and self-evident to most anybody with a soldering iron but here we go….

First a primer on headlamps. Rated at 55 watts, an H4 lowbeam headlamp consumes around 55 watts, I guess, which is something like 4-5 amps. With a 240 watt alternator and with barely any charge below 2500 rpm, goofing around in the city, prior to cranking on a cold morning, or when your electric system is failing, it would be good to be able to switch off the lamp. Moreover, the parking lamp is on all the time and can make-do for a substantial part of the safety and regulatory issues, especially in the daytime. Finally, if you need some lamp action, you can always flick on the highbeam the two habitual ways which are unaffected by this mod.

Ampmeters versus Voltmeters

I see little reason in having having an ammeter permanently installed on any BMW motorcycle, unless you have special circumstances. I foresee several drawbacks, not the least of which is a potential fire hazard, which includes burning up your bike’s wiring; besides the usual situation of LESS reliability with many modifications; especially with added electrical items. I will lay out the benefits, and the problems, for both ammeters and voltmeters. The GEN lamp provides quite a bit of information if you interpret it correctly….but it may not be enough FOR YOU.

Electrical Wire Upgrade

To help the voltage regulator and the entire charging system, an easy and inexpensive upgrade is to replace old, small, worn and sometimes corroded stock BMW wires with a set of upgraded heavier wires you make yourself. Here’s how:

The Best Wire to Use

For the best wire, go to a marine supply store and look at their selection of bulk wire. They will have wire as thin as 22 gage and as thick as 6 gage, with costs ranging from $.11 to $.49 per foot. The marine wire is rated for 600 volts, is oil-water-gasoline resistant, and is made with very fine multiple strand wire. The finer the wire used in the multi-strand wire, the more flexible the wire will be to handle and install, which is important when working within the tight confines of a motorcycle.

If you can’t find a marine supply store, auto parts and hardware stores also carry quality multi-strand wire at reasonable prices. I have used this material in the past and it works well but is not as flexible as the marine grade wire.

Bike Storage Preparation

It’s that time of year again, so I thought I would post the storage procedures that are contained in the 1978 BMW Owner’s Manual for those of you that don’t have access to such. The following is a reproduction of the storage procedures specified by BMW on page 35 of the 1978 BMW Owner’s Manual:

If you intend to lay up your motorcycle during the cold season of the year or for a long period, the following precautions will help to guard against corrosion and superficial damage:
Drain the oil when the engine is warmed up, clean the oil mesh strainer and oil sump.
Add corrosion inhibiting oil up to the lower mark on dipstick (app. 1 Liter = 1.05 US quarts). Run the engine for about 1 minute off-load. Remove the oil filter and close the empty filter chamber. When storing for more than 6 months, drain oil from gear-box, swing arm and final drive and add corrosion inhibiting oil. Contents: gearbox 0.4 liter (0.4 US quart), swing arm 0.05 liter (0.05 US quart). Place the machine on its center stand, engage 2nd gear and turn the engine at a fast idle for a few seconds.

Centerstand Repairs

Owners of early BMW twins are divided into two sorts; those whose centre stand bolts have failed and those whose bolts are going to fail soon. The root of the problem is that on the pre-square air filter models the stand pivots on bushes retained by a pair of bolts which screw directly into the frame. The continued heaving on and off the stand eventually loosens the bolts and the threads in the frame will start to fret. Retapping the frame to the standard thread (M10x1.25) and replacing the bolts delays the evil day, but when I found a bolt lying under the bike only days after doing this, I knew it was time to look for a better solution.

Wheel Bearings

These procedures may seem complicated at first, but in reality it takes only minutes, once you have done it previously. MUCH of the information will not, perhaps, apply to YOUR motorcycle, but it all does need to be read, and understood.

BMW Airhead motorcycles are relatively tolerant to abuse and poor maintenance. Our human bodies are not tolerant to being dumped on the road at speed from a motorcycle. Of all the items that are safety related, the mechanically most important are the condition of the wheels, tires (tubes if any), brakes, wheel bearings. For non-mechanical, well, of sorts, one could add the importance of the rider’s clothing, and, in particular, the rider’s condition and competence/skill.

Discussion of ‘Tank Slappers’–Part 1

Discussion of Tank Slappers–Part 1 (Snowbum) Since the original publishing of the discussion about tank slappers”, I finished writing an extensive article on that and allied subjects. This was after accumulating a very large number of tests on a large number of BMW Airheads, mine, and customer’s bikes. The article is on my website. Here […]

Type V Fork Rebuild Tips

When I did research on rebuilding the forks on my 88 R100 RT, I found very little information regarding the “Type V” forks on the monoshock RT and RS’s. And, what little I found turned out to have a significant amount of incorrect information. I’m writing this to be used in companion with other information. Clymer indicates the wrong damper rod assembly for the Type V forks. In addition, the exploded views of the forks by both BMW and in the Clymer book are missing an O ring on the damper rod assembly. The BMW fiche indicates only one O ring located on the damper rod; however, there is an O ring on the valve, which is not shown. This O ring on the valve is the same O ring that is on the damper rod, so just double the order. Since I had a hard time trying to figure out what parts to order, I have included a parts list at the end of this article.

Throwout Bearing Maintenance

Sure… The reason I suggest doing this, is due to the nature of the layout of the rollers in the bearing. Before the ’74’s (/5 and earlier), BMW used a ball bearing throw-out assembly. They went back to this after 1984. If you referrence a price list, you will see that the ’74 to’84 roller set up is a LOT cheaper. The rollors are laid out radially in a circle.This insure that as the rollers attempt to roll, one end will go faster than the other and will scrape on the two “thrust pieces” on each side.

1 2 3 … 8 9 10 11 12

Posts navigation