Stiff throttle - 2002 R1150R

[Radek]

I have lubed the cables with WD-40, but I find the throttle stiff. After just half hour of riding my thumb gets numb. Kaoko Throttle lock helps, but I would like the throttle to be smooth (like most japanese bikes).

I have heard rumors that the BMW grips may also contribute to the problem, so I am going to install grip puppies.
Also, I have seen posts indicating that a new (upgraded?) throttle cable might help? Any experience about this?

Please post part #s that have worked for you.

Thanks!

[gregor]

Not had problems with mine or heard of any. Unlucky- has it been sitting in the rain? And I can hold the throttle open by my heavy handed approach while sitting bolt upright.
Dismantling enough to lube would, maybe with a silicone lube, be my first approach. Then get more serious about dismantling .Beware then you may get into throttle synchronisation problems..

[CycleRob]

Radek, You don't mention anything about your bike's age or model. It can be a gummy handlebar and throttle tube junction, contaminated with grip glue, corrosion and/or hardened and contaminated grease. The most likely throttle binder is in the metal elbow where the cable connects to the throttle housing. Normally the throttle cable is surrounded by an anti-friction plastic pipe it's entire cable length and the slimy factory lube stays there for years. When/If acid/dirty rain water gets in there it eventually corrodes the throttle wire. Then the wire turns into an abrasive cutting wire that saws thru the plastic pipe at the 90 degree elbow, where it then really binds against the metal elbow internals. Seen this happen on an older bike after pulling out the chewed up internal piping portion. It can also be hardened/dirty grease in the very hard to get at throttle junction box under the battery. Your best bet is to take the whole system apart for forced lube cleaning and greasing, followed by a precise TB synching, several hours in total.

Using a power cable lubing system like THIS (plus the special lube that makes it complete) is the best one made, for bike wrenching owners. My F800ST has a cable operated clutch release, so owning it makes it even more valuable.

To prevent water entry, ensure the rubber cable cover is not cracked and IS where it belongs. You can even grease it where it seals against the throttle cable outer cable. If your bike is over 10 and often ridden in the rain, a new throttle cable may be needed, hopefully before it is really needed.

[Radek]

It's a 2002 as in the subject line. It's got about 45K miles. Has been in rain while riding, but that is expected.

I am going to dismantle the cable line and check it out. If cable is corroded, I will replace ...

[CycleRob]

Maybe it's just me . . . . but working on the R1150R throttle cable system is by far the most frustrating throttle I have ever worked on. The right mirror stalk has to come off to access a hidden screw. The fast idle lever's cable is a Chinese puzzle to take apart. The throttle junction box is difficult to remove in that the fast idle cable end at the handlebar and both TB cables need to be detached so the left cable can pass thru the throttle junction box's retaining bracket and the very short right TB cable does not restrain the removal.
On the plus side, it is the BMW techs that will most likely have to deal with it, but unfortunately, well after the 3 year warranty has expired. Looking at what the engineers did deserves some credit in that the throttle junction box is well made, well protected from the weather and invisible. When you get it out-n-apart, you'll see how the fast idle "ramp" works and how you can adjust the cable freeplays to take away lost motion and get the most out of it.

These pics will help:


EDIT: To update to a better, faster photo host and enhance text.

[Radek]

Thanks for the pics. Just looking at the pics is giving me a headache!

I will at least check out the condition of the cables and such and lube it first, then if that doesn't work, dismantle the beast!

Maybe it's just me . . . . but working on the R1150R throttle cable system is by far the most frustrating throttle I have ever worked on. The right mirror stalk has to come off to access a hidden screw. The fast idle lever's cable is a Chinese puzzle to take apart. The throttle junction box is difficult to remove in that the fast idle cable end at the handlebar and both TB cables need to be detached so the left cable can pass thru the throttle junction box's retaining bracket and the very short right TB cable does not restrain the removal.
On the plus side, it is the BMW techs that will most likely have to deal with it, but unfortunately, well after the 3 year warranty has expired. Looking at what the engineers did deserves some credit in that the throttle junction box is well made, well protected from the weather and invisible. When you get it out-n-apart, you'll see how the fast idle "ramp" works and how you can adjust the cable freeplays to get the most out of it.

These pics will help. Click Thumbnail. Moving mouse cursor off the pic auto-hides the top menu icons if they are in the way.