R65 Stuck Throttle

[kls1]

Hi again,
Thanks for all the info btw. So I'm just starting off work on my 1983 r65, and the throttle sticks quite a bit. In fact, it's pretty much a built in cruse-control.

I talked to another mechanic, and he said this was a common thing with old bmw's. He seemed to be suggesting it's not fixable. Can anyone offer input? Thanks!

[Bob_Roller]

Most likely a worn  or bound up throttle cable.

Check the routing of the cable, to see if it is getting pinched somewhere.

There's a cable 'splitter' under the tank, it allows a single cable at the handlebar, and then the cable has two outputs from the splitter to each carb.

You can try lubing the inner cable to see if it helps any, but it will require the cables to come off.

It just might be time to replace all three cables, I think they are around $20 each in the US.

[Ed Miller]

New cables ARE nice.  You can also clean, examine, and relube the throttle gears and handle.  The only time mine seemed to have a cruise control was when I shoved a new right hand grip on a bit too far, and it was rubbing against the brake lever assembly.

Make sure your throttle return springs are working right, though I don't think they would give you the symptoms you describe.

In the mean time, you can wave at people with both hands!

[Bob_Roller]

Ed's right, if the bike is new to you, and you have no idea what's been done to it in the past, you might as well take it all apart clean, inpect for obvious problems , lubricate and put it back together again.

[kls1]

Thanks for the advice guys. I was expecting to have to replace/fix a lot of things, I just wanted to make sure I was heading towards the right fixes.

[Lowen]

Is the throttle lock on? My throttle used to stick when I first got my 84 and it turned out to be bent splines on the throttle tube due to lack of grease. New throttle tube and gear with lots of grease solved the problem.

[Semper Gumby]

Hi KLS1,

I would take apart the throttle and clean and lube the bar and the gear with Lubriplate No. 630-AA(really light grease NLGI 1.)

Where the cable goes into the ferrul on the top of the carb the cable sheath usually breaks and rather than coming out straight, the cable and the ferrul are at an angle to each other.  If this is the case stop now and replace the cable.  Otherwise.....

Then I would take apart and seperate the cables and the splitter.  Pull the wire through each cable - if it drags at all then replace the cable.  BMW cables have a teflon liner and should not be lubricated.  Clean the splitter with some brake cleaner and reassemble.  Check the springs on the carbs and see if one is broken (not likely) remove the springs and turn the butterfly by hand and see if it is binding in any part of its range.

If it is then look up the procedure for removing the throttle butterfly (it is difficult - small screws shotpeened in place.)  I would replace the o-rings on the throttle butterfly bar and re-assemble with coating of the Lubriplate grease on the o-rings.

Now you have gone through the entire throttle system.

Good luck.

[airhead]

Make sure the throttle lock isn't screwed in. Under the bar twist grip just where it enters the cable cam housing there should be a 20mm or so diameter aluminium screw with a slotted and/or knurled head. This is a kind of cruise control and depending how far it's screwed in will either lock the twist grip solid, or give varying amounts of sticktion.

Bill............................;-)

[thrang]

I'd replace the cables and grease up the twist grip... Oh and new springs on the throtle return on the carb migh help. Tony