Throttle Control Assembly Cam Disc

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CharlieVictor
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Throttle Control Assembly Cam Disc

Postby CharlieVictor » Fri Sep 08, 2017 8:08 pm

Hello all,

Does the cam and its little chain tranmission require any lube please?
I find my throttle a bit stiff, and was wondering if it could be the cam or possibly the locking bolt.
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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windmill john
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Re: Throttle Control Assembly Cam Disc

Postby windmill john » Fri Sep 08, 2017 8:30 pm

Two things.

Yes the cam and chain needs lubing, a decent grease, I use Corrosion Block.

If your throttle is sticking, the actual throttle body/slide, the tube inside your grip is quite easy to deform.
Check where it enters the area where the chain is, it might be catching there.
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Schorsch 1978-80 R65 - bit of a Shetland pony; frisky and naughty.
Friedrich 1993 R80RT - a Percheron, but can still mix it with the rest.

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Fri Sep 08, 2017 8:37 pm

Thanks John, greatly appreciated.
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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windmill john
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Re: Throttle Control Assembly Cam Disc

Postby windmill john » Fri Sep 08, 2017 9:28 pm

Could even be the inside end of the grip catching the end of the handlebar.
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Schorsch 1978-80 R65 - bit of a Shetland pony; frisky and naughty.
Friedrich 1993 R80RT - a Percheron, but can still mix it with the rest.

barryh
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Re: Throttle Control Assembly Cam Disc

Postby barryh » Fri Sep 08, 2017 10:10 pm

The pot metal cam gears need cleaning and greasing on a routine basis if they are to last and even then the first few teeth in most constant use tend to wear. It's a good throttle design with a deliberate non-linear action but the material quality of the gears is not great.

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Sat Sep 09, 2017 9:12 am

Thanks guys. prompt answers greatly appreciated.
I'll check it out this weekend.
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Sat Sep 09, 2017 5:37 pm

All done after a little bit of drama... The cam mark was not properly lined-up with the throttle tube mark, which might have explained the stickyness, but when I tried to adjust it the thing just popped out !!
Anyway, lo and behold it's back in place (phew!), properly lubricated and cam in line with tube. No more stiffness, works even better than before !

Thanks again for the quick response and valuable information.
:wink:
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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windmill john
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Re: Throttle Control Assembly Cam Disc

Postby windmill john » Sat Sep 09, 2017 5:40 pm

Yup, that top throttle cable likes to pop out too when you have that cover off!
A simple mechanism, but three hands would be good.

Glad it's all good.

John
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Schorsch 1978-80 R65 - bit of a Shetland pony; frisky and naughty.
Friedrich 1993 R80RT - a Percheron, but can still mix it with the rest.

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Sat Sep 09, 2017 5:43 pm

Actually make it four, since one of them has to hold the flashlight !!
Thanks a lot John ;)
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Mon Sep 18, 2017 1:22 pm

Further inspection revealed a frayed cable at the left carb... I just had time to order a new set of throttle cables before leaving on vacation, and they arrived as I was away.

Back home now and ready for install ... 8-[

Any hint, suggestion, advice, helpful trick or recommendation on that (for me) daunting task ?
Like, should I start by attaching the carb end or the handlebar end ?
Will I need to redo the carb synch afterwards?

Thanks for any help you may provide... :pale:
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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Galactic Greyhound
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Re: Throttle Control Assembly Cam Disc

Postby Galactic Greyhound » Mon Sep 18, 2017 1:53 pm

Like Throttle Cables on ANY bike it is vital to maintain the original factory routing and fixing.

This can be achieved by noting any retaining clips/ties and tying a piece of string to one end of the old cable before pulling the cable out.

The new cable is then tied to the string and pulled through so keeping the original routing.

Be careful if cable ties are used to hold a Throttle cable in position.
Generally speaking, any cable ties used should only be fixed VERY loosely to the cable or the Throttle may hang up when the bars are turned.

It is better to avoid the use of ties and clips where possible for this reason.
Ced.

R1100RT 1996.
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Re: Throttle Control Assembly Cam Disc

Postby Artie McMurray » Mon Sep 18, 2017 3:39 pm

I have found it helpful when fitting the cables to fit them to the carbs first and when fitting to the throttle, fit the left hand cable to bottom of the fitting, hold it down in place with your right hand, as you fit the right hand one to the top of the fitting, with your left hand lift the lever on the right carb (it's easier to reach than the left carb) until you have the cable in place then gently release your left hand and the resulting tension should hold it in place until you get the top on. Well it worked for me!

It's not a bad idea to have a good screw to hold the top on, in my case an Allen countersink screw, and check it's security from time to time. Shortly after I got my R80 I was accelerating away from traffic lights and the cables popped out, so unless you want to do the job at the roadside, check the screw !!
Artie

78 R45

92 R80 RT

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Tue Sep 19, 2017 6:37 pm

All done.
Actually you can't properly hook up the cable tips to the cam box if they are already hooked up to the carb (unless you have someone able to pull on the lever while you attach the tips at the cam box). And if you are on your own as I was, with only two hands, it's very tricky...

Took me the best part of three hours, including tune up, with the camchain cover popping out at least fifty times ( ](*,) ](*,) ](*,) ) but for some unknown reason I'm much more patient when I fettle the bikes than in any other circumstances !!

No need for a full carb synch either, just a proper idling adjustment.
She runs like a charm... again !! \:D/


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1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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windmill john
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Re: Throttle Control Assembly Cam Disc

Postby windmill john » Tue Sep 19, 2017 6:56 pm

The only fly in the ointment is, you will get noticeable initial cable stretch with a new cable, so you will find you need to sync the carbs after a few miles.

John
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Schorsch 1978-80 R65 - bit of a Shetland pony; frisky and naughty.
Friedrich 1993 R80RT - a Percheron, but can still mix it with the rest.

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Tue Sep 19, 2017 7:02 pm

Got it.
Thanks a bunch John :wink:
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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windmill john
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Re: Throttle Control Assembly Cam Disc

Postby windmill john » Tue Sep 19, 2017 9:24 pm

I do like to insure that your silver lining is suitably dulled with a bit of grey :grin:
http://www.kittos.co.uk
Best roads: 623 Burgos to Santander. A back road to Metz; can't remember which!
Schorsch 1978-80 R65 - bit of a Shetland pony; frisky and naughty.
Friedrich 1993 R80RT - a Percheron, but can still mix it with the rest.

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Wed Sep 20, 2017 8:13 am

Two black cats living at home is better than formal training ! :bounce:
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"

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CharlieVictor
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Re: Throttle Control Assembly Cam Disc

Postby CharlieVictor » Sat Sep 30, 2017 7:20 pm

Incidently and if it can help other members, I didn't try to follow the OEM routing for the cables at all, but actually let them run free without going under the tank.
After 20 miles, I adjusted the idling again as John warned me about, and then losely (I underscore LOSELY) secured the cables to the frame tubes with zip-ties.

Works a treat.
No more sticky throttle, or variation in rpm when turning, or "rough spot" at 3000 rpm...
1978 BMW R100S "Naked"
1999 W650 "Twin with a kick"


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