Quattro Report

2004 “2-Spark” BMW R1150RT

Wisconsin Capitol, Lake Monona, and 2004 BMW R1150RT

Initial report by Jeff Dean on 2004 Biarritz blue BMW R1150RT.

Purchased 28 March 2003 from Iron Horse Motorcycles, Tucson, Arizona. Initial odometer, after prep, 13 miles. Six-hundred-mile service completed at 751 miles by master technician Paul Ford on April 8, 2003.

Differences in 2004 R1150RT from 2003 R1150RT:

  • Two-spark technology in each cylinder (see photo above, right);
  • Therefore, different valve cover protectors required (see photo above, left);
  • No radio prep kit installed;
  • Maintenance-free BMW gel battery (see charger info below);
  • Does not accept 2003 European headlight switch.
Installations at start: Metzeler ME880 tires, front and rear, exchanged for stock tires. Moved over from 2002 R1150RT traded: Bob's wrist rest; front fender extension; Hyper-lights and hyper-turn signals; extra-tall Cee Bailey windscreen; PIAA driving lights on EMP brackets; Kisan headlight modulator; RCU shelf (for Valentine 1 and voltmeter); Cycle Gadgets GPS mount (for Garmin Streetpilot III); and Aeroflow headlight cover. Euro switch could not migrate.

First riding impressions.

The engine is extremely smooth, moreso than any of the numerous 1100cc and 1150cc oilhead RTs I have previously owned and ridden, although my 1999 R1100RT-P does come close. There is no hint of surging or “hunting” at any engine speed; apparently this problem some owners have experienced is past history.

It seems to me to have more low-end “grunt” than my other R1150RTs. That is, the engine seems somehow more “eager” to me. The difference is subtle, but I do not think it is my imagination. Could that be more complete fuel combustion with two plugs?

The rear-brake pedal seems just about as sensitive as on 2002 and 2003 models, which is to say very touchy. I have read that BMW has attempted to lessen this effect. If true, my size-13 right foot doesn't feel it.

The transmission seems to shift more smoothly, but I cannot be sure that it really does; has the tranny been improved, or could it be my imagination?

The deep metallic blue color is stunning in sunlight. I have received a lot of compliments on the color, and those are new to me. I assume that the sea off Biarritz, France, must also be stunning.

The photo above left shows the cockpit of my 2004 R1150RT, including its RCU shelf with voltmeter and Valentine 1 radar locator, and an Airguide thermometer below it. Above right shows BMW's auxilliary tail lights both sides of the license plate, and Hyper-Lites under the stock tail light. The photos below show a PIAA driving light, left, and Aeroflow headlight guard, right. For information on these and other R1150RT accessories, click here.

My first fill-up of gas gave mileage of 45.6 MPG (5.2 liters/100km), which is generally better than my earlier R1150RTs got. Other tanks have been a little less, but still excellent. My 2002 R1150RT averages overall 41.1 MPG, and my 2003 R1150RT only averages 40.86 overall. The 2-sparker is an improvement. The only better mileage I have obtained was with my K1200LTs and my R27s.

Mileage update 6,200 miles later: The ‘04 RT has produced overall mileage of 42.52 MPG, with a best tank of 46.36 MPG. So it is producing about 1-2 MPG better than my previous R1150RTs. Other riders who are smaller and lighter than I am, and who use smaller windshields, should get better mileage. For example, my friend Mark Weiss, who is 65 pounds lighter than me and rode with a smaller windshield, borrowed my 2003 R1150RT for about 1,300 miles and produced average mileage on that bike of 46 MPG, with a best tank of 47.9 MPG. So rider weight and windshield selection make a huge difference.

Battery chargers for the 2004 gel-cell motorcycles.

There are only two chargers approved by BMW Motorrad USA for use on 2004 and later BMW motorcycles equipped with gel batteries. One is the BMW Advanced Battery Charging System made by Deltran and “Programmed for BMW Gel Batteries,” which has BMW part number 99 99 0 005 656. Its retail price is about $80. The second charger is described in the following cautionary service bulletin of April 2003 issued before the Deltran charger went into production:

BMW Motorrad USA Service Bulletin
Date: April 2003

Bulletin No: 61 002 03 (007)
“Instructions for Handling Gel Batteries”

Gel batteries must be charged before being installed in a motorcycle. This applies to gel batteries from parts stock or during PDI   (note: Pre-Delivery Inspection). There is currently only one battery charger approved for use when charging or maintaining a gel battery through the BMW accessory power socket. This charger is available from BMW by ordering Part number: 72 60 7 679 040.

In charging a battery other than through the accessory power socket, only chargers especially designed for gel batteries may be used. This means that chargers previously approved by BMW Motorrad or “trickle” chargers are not suitable for charging or maintaining Gel Batteries.

There are commercially available battery chargers that are suitable for charging gel batteries. However, when using a charger acquired commercially it absolutely must be ensured that the gel battery has been removed from the motorcycle or that the battery has been isolated from the vehicles electrical system. The battery must be isolated because gel battery chargers perform a so-called desulfation cycle, in which the charge voltage increases to over 15.5V for a limited time. If the battery is connected to the electrical system during charging this spike could lead to failure of the control units and other electrical/electronic components.

Gel batteries can be exposed to a charge voltage of 14.4V for only a limited period of time. Continuous charging with 14.4V or higher will damage the battery. When charging at 14.4V excessive quantities of Hydrogen and Oxygen gas are produced that cannot be recycled into water and will cause the internal pressure of the battery to increase drastically. When a certain internal pressure is reached, the pressure relief valve opens allowing the gasses to escape. The opening of the relief valve will render the battery useless.

In contrast to “wet” batteries from BMW, Gel batteries have a “Use-by” date. This date indicates the end of the batteries unused shelf life at room temperature. The “Use-by” date is on the rear of the battery housing. Please pay attention to your inventory of Gel Batteries as Warranty cannot be claimed for new Gel Batteries which are past their use-by date.

In the event of an anticipated interruption in use, longer than one month, the Gel Battery must be charged with a suitable charger. This ensures the Gel Battery goes into the period of disuse fully charged and is not left in an undefined charge status.

When using a Gel Battery in the motorcycle, maintenance of the battery during longer interruptions in use or while the bike is in storage must not be neglected. Please bring this to the customer’s attention.

It is important to remember that only the BMW Charger, part number 72 60 7 679 040, is approved for use when charging the battery through the vehicles power accessory outlet.


The new BMW battery charger for gel-cell batteries (above, left) came on the market in May 2003. It is BMW part number 72 60 7 679 040. Retail price is a hefty $115. The later Deltran charger (above, right), “Programmed for BMW Gel Batteries,”  lists for about $80.