Throttle cable install tips

[Runninn1]

Any updates on an easier way to install the bar-end throttle cable?
Standing on my head while doing backflips is getting old...Perhaps using a cardboard template & carefully removing it while screwing in the Phillips head retaining screw....

thanks

[Warbucks]

Assuming that you have a single cable attached at the throttle, have a look at the gear on the inside end of the throttle. The gear mates with the gear inside the housing. It has a mark stamped on one of its teeth. Line that mark up with the mark on the gear inside the housing. Hold it in place and stretch the chain out to the end of the housing (where the cable connects).

Make sure that you have the housing cover in close proximity to the hand that is holding the gear in place. Next, connect the throttle cable and carefully place the housing cover on top. (You need two hands to do that). Once it's there, firmly press it down as far as it will go and put the screw back in. Keep the pressure on the housing cover until the screw is tightened.

When putting the housing cover back on, make sure that the gear does not move. When its assembled, twist the throttle forward. If you have reassembled it properly you will get to a point where the throttle cannot be twisted any further forward when the butterflies on the carbs are closed.

If it's not done correctly, the butterflies on the carbs will be closed and you'll still be able to twist the throttle forward past that point. That being the case, start the above procedure again.

It just takes a bit of practice doing this before it becomes easy. It's probably a good idea to re-assemble it with fresh grease, but don't overfill the housing. The grease will help the gears to stay mated while you're putting the cover back on.

I hope that all makes sense.

[Barry]

The twin cable set up at the throttle is even more fun and games to get that top cover back on while trying to fight the tension put on the inner cables by the carb return springs. There are several options to make it easier.  Either disconnect the return springs or disconnect the inners at the carb end taking care not to put a kink in the inner cable. Or you could even contrive a means of jamming the butterflies open a little to provide a enough free play in the cables. A pencil under each butterfly will do it.

[montmil]

Barry's mention of installing twin throttle cables reminded me of my escapades of just two weeks ago...

Replaced the wide, street tracker-style bars on the 1978 R100S with the correct OEM BMW bars. Now then, much nicer looking. But...
   Discovered a previous owner had hogged out the control perches to fit the thick powder coating on the 22mm diameter bars. Attempting to snug up the perches onto the new BMW bars proved impossible. One change always seems to lead to another.

Internet BMW Riders Marketplace and pal Bengt Phorqs directed me to a gent with both perches, w/ tatty levers, for sale at $40.00. Got them, worked out a couple minor scuffs, cleaned them up and shot some semi-gloss black to match the switch assemblies. One fly in the ointment was the buggered gear teeth on the 'new' throttle tube. Replaced that with mine and we're ready to fit cables and cover.

As many know, it's a near impossible task to keep the gears in synch while attempting to maintain an even pull on the twin cables and that miserable little chain while getting the cover back on properly.

Rather than disconnect the cables at the carbs or remove more pieces to hold the butterflies open, a couple pieces of 5/16-inch thick wood scraps were lodged between the throttle levers at WFO and the carb body. This provided enough slack to fit all the throttle components in place with zero angst.

Did this procedure twice as I had mis-matched my original throttle tube gear with a different BMW part number gear-chain bit. One tooth off provided a 2000 rpm idle! May have well been a dozen off as I had to open up the top cover and do it all again.

 [smiley=wall.gif]