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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: Nantucket_Red on June 21, 2015, 08:13:26 PM

Title: Sticky throttle, before and after
Post by: Nantucket_Red on June 21, 2015, 08:13:26 PM
Before:
https://www.youtube.com/watch?v=zSM1X9ahbmM

After:
https://www.youtube.com/watch?v=s66i42RZw6M

There is still a little bit of return lag when the bike is on. Could it be the return spring on the linkage? I haven't check that yet as it is raining currently. Either way it is heaps better now.

(why I was trying to turn the grip the wrong way is beyond me...)
Title: Re: Sticky throttle, before and after
Post by: The Mighty Gryphon on June 21, 2015, 10:51:36 PM
(why I was trying to turn the grip the wrong way is beyond me...)

Since you live on the Cape, do you have a boat with an outboard?  I run one on a workboat and still will occasionally try to turn the throttle in the direction of a bike throttle when I'm running right handed.
Title: Re: Sticky throttle, before and after
Post by: TimTyler on June 21, 2015, 11:00:33 PM
Your throttle lock is disengaged, right?
Title: Re: Sticky throttle, before and after
Post by: Nantucket_Red on June 22, 2015, 05:35:20 AM
Your throttle lock is disengaged, right?

 That dongle with the spring? Should be, but I'll double check it.
(why I was trying to turn the grip the wrong way is beyond me...)

Since you live on the Cape, do you have a boat with an outboard?  I run one on a workboat and still will occasionally try to turn the throttle in the direction of a bike throttle when I'm running right handed.

Used to, old habits die hard lol
Title: Re: Sticky throttle, before and after
Post by: Nantucket_Red on June 22, 2015, 07:02:53 AM
Removed it completely. No change, there is no snap back from minor blips of the throttle.
Title: Re: Sticky throttle, before and after
Post by: TimTyler on June 22, 2015, 09:51:12 AM
I'd remove the throttle cable from the throttle bodies and the throttle grip. Then I'd feel for resistance in the grip, the cable and the throttle bodies independently. I bet you need a new cable. If the cable is original it's not a bad idea to replace it anyway. Keep the old one in your cowl as a spare.
Title: Re: Sticky throttle, before and after
Post by: Nantucket_Red on June 22, 2015, 11:43:41 AM
Seeing as I haven't tried that, I might as well.
Title: Re: Sticky throttle, before and after
Post by: jetpoweredmonkey on June 27, 2015, 09:30:19 AM
You may need a new cable, but step one is to remove the throttle cam cover by the twistgrip, remove your bar end weight, take the twistgrip off and clean out all of the old gunky grease in the throttle cam and gears, inside the twistgrip tube, and on the handlebar.  Clean everything well, reassemble with fresh grease and see how it feels.  I have yet to buy an old BMW that has ever had any attention paid to this rather unique setup and all of them feel gross and draggy.
Title: Re: Sticky throttle, before and after
Post by: The Mighty Gryphon on June 27, 2015, 10:01:07 AM
You may need a new cable, but step one is to remove the throttle cam cover by the twistgrip, remove your bar end weight, take the twistgrip off and clean out all of the old gunky grease in the throttle cam and gears, inside the twistgrip tube, and on the handlebar.  Clean everything well, reassemble with fresh grease and see how it feels.  I have yet to buy an old BMW that has ever had any attention paid to this rather unique setup and all of them feel gross and draggy.

I need to do that to both of my K's, but the damn heater wiring scares me. 
Title: Re: Sticky throttle, before and after
Post by: buddymack on January 31, 2016, 03:39:46 PM
Anybody just replaced the throttle side perch with something from another bike?  Frankly I'm not a fan of the original gear on gear drive design.
Title: Re: Sticky throttle, before and after
Post by: rbm on January 31, 2016, 03:51:13 PM
I take it you're referring to the K100 throttle. Throttle from a K1100 will fit with very little fuss, on a K100.  It is more like a Japanese bike with a direct throttle cable attachment, and no gearing inside the throttle housing.  If you mean from a Japanese motorcycle, then yes others have done that. (http://www.motobrick.com/index.php/topic,6775.msg46585.html#msg46585)
Title: Re: Sticky throttle, before and after
Post by: Martin on January 31, 2016, 04:06:10 PM
I've never had any problem with my cable or the throttle mechanism, but  I clean it once a year and relubricate it with lithium spray grease. I also use TRI FLOW PTFE spray lube on all the cables 2-3 times a year. BMW does not recommend lubricating cables, but I've had the bike 17 years & done 150,000 K's. TRI FLOW is available from bicycle shops.
Regards Martin.
Title: Re: Sticky throttle, before and after
Post by: buddymack on February 03, 2016, 04:39:14 PM
Thanks.  I'll start looking at the K1100 option.  Throttle tube gearing is damaged and new is NLA.
Title: Re: Sticky throttle, before and after
Post by: Chaos on February 03, 2016, 04:56:31 PM
did you pull the grip off the handlebar and clean that up?  that's where mine was hanging up, lots of crud builds up in there.
Title: Re: Sticky throttle, before and after
Post by: Laitch on February 03, 2016, 05:06:51 PM
Thanks.  I'll start looking at the K1100 option.  Throttle tube gearing is damaged and new is NLA.
It's listed as available at MAXBMW. Section 32, Diagram #32_1967 in K100RT, buddymack. Part #8 and maybe you'll need #7, too. http://www.maxbmwmotorcycles.com/fiche/DiagramsMain.aspx?vid=51754&rnd=07012015

If the throttle tube itself is damaged, that looks like #24.






Title: Re: Sticky throttle, before and after
Post by: buddymack on February 04, 2016, 07:52:55 PM
I take it you're referring to the K100 throttle. Throttle from a K1100 will fit with very little fuss, on a K100.  It is more like a Japanese bike with a direct throttle cable attachment, and no gearing inside the throttle housing.  If you mean from a Japanese motorcycle, then yes others have done that. (http://www.motobrick.com/index.php/topic,6775.msg46585.html#msg46585)
Haven't had any luck finding a K11 throttle assembly.  Any suggestions on where to look?
Title: Re: Sticky throttle, before and after
Post by: Laitch on February 04, 2016, 07:54:07 PM
Well, you can always repair what you've got anyway.
Title: Re: Sticky throttle, before and after
Post by: buddymack on February 05, 2016, 09:54:48 PM
Found a used stock throttle tube, cleaned it thoroughly, filed the gear end removing any burrs, and installed it.  For the first time ever, the throttle springs closed when released!  I can live with that!
Title: Re: Sticky throttle, before and after
Post by: Laitch on February 05, 2016, 09:58:22 PM
Now that's what we're talking about!
Title: Re: Sticky throttle, before and after
Post by: john11668 on April 11, 2016, 06:30:16 AM
Took my  bike out for a run on Saturday and was surprised by the effort required and  to a certain extent found it tiring on that hand.
Also the free play in the cable needs taken up as it is not conducive to smooth riding in traffic.  I suppose that on a 30 year old machine you can expect some crudding up and it clearly wasn't a priority to the previous owner .
Will have a look at the manual   but are there any tips
Title: Re: Sticky throttle, before and after
Post by: Laitch on April 11, 2016, 07:58:44 AM
Remove the cutoff switch plate by unfastening the small screw at the bottom. Remove the screw from the top of flat throttle gear housing to the right of the combo switch. Clean out the old grease, add fresh lithium grease or silicone spray. Align the mark on the gear with the mark on the assembly. Reassemble everything then be sure the flange on the grip isn't rubbing the house and your throttle screw on the back side of the throttle to the right of the switch/throttle gear assembly—if your bike has one—isn't engaging the throttle.
Title: Re: Sticky throttle, before and after
Post by: The Mighty Gryphon on April 11, 2016, 08:48:17 AM
If you want to get the chain and gear out to do a good cleaning you will need to move the front brake master cylinder. 

There are two fillister head screws that hold it on to the perch.  They come in from the side facing the instrument cluster, one in the front under the reservoir, and the other near the wire for the brake switch.  Take them out and lift the reservoir and you can get all the throttle stuff out to give it it's first good clean in 25 years.