Throttle sticking

PostPost by: saildrive2001 » Tue Oct 30, 2012 9:43 pm

I know this has been discussed in the past & I have read the old posts. I have tried to make the cable align with the pedal, lubricated the cable etc. but it still is sticky when opening the throttle. Suprisingly even without any additional return spring (only the ones on the Strombergs) the throttle returns without any hesitation or sticking.
My car is a RHD so the cable has to do that horrible double bend. I am using a new outer & inner from a motorcycle shop.
What are any of you using for the cables?
Keith Marshall
69 S4 SE DHC RHD Original owner
saildrive2001
Fourth Gear
Fourth Gear
 
Posts: 597
Joined: 29 Oct 2003

PostPost by: prezoom » Wed Oct 31, 2012 3:50 am

I use a rear brake cable from a tandem bicycle, since mine is LHD and I need the extra length. Buy bulk teflon lined outer housing and use a "noodle" from mountain bike V brakes to make the turn out of the footwell. Seems to work quite well, no drag or sticking.

Rob Walker
26-4889
Rob Walker
26-4889
50-0315N
1964 Sabra GT
1964 Elva Mk4T Coupe (awaiting restoration)
1965 Ford Falcon Ranchero, 302,AOD,9",rack and pinion,disc,etc,etc,etc
1954 Nash Healey LeMans Coupe

Owning a Lotus will get you off the couch
prezoom
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1337
Joined: 16 Mar 2009

PostPost by: oldelanman » Wed Oct 31, 2012 9:33 am

If you are making your own cable be sure to make it long enough. Too short and the bends will be too tight and it won't pass squarely through the abutment bracket on the cam cover which will cause the inner to snag on the edge of the hole in the outer cable ferrule. The outer cable length on my RHD with Strombergs is currently 29" overall and it works fine at that but it could probably do with being an inch or so longer to allow for cable tying it to the battery cable. Like Rob I made mine from a bike brake cable.
Attachments
Throttle cable routing.jpg and
Roger
S4 DHC
oldelanman
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1969
Joined: 02 Jan 2008

PostPost by: saildrive2001 » Wed Oct 31, 2012 12:41 pm

Thanks guys I will go to the bike shop today.
Roger, have you got any details that you can share about your choke mods? Although I am trying to keep my car as original as possible the choke cable routing is really bad. I have bbeen thinking of making a better arrangement than the stock item.
Keith Marshall
69 S4 SE DHC RHD Original owner
saildrive2001
Fourth Gear
Fourth Gear
 
Posts: 597
Joined: 29 Oct 2003

PostPost by: oldelanman » Wed Oct 31, 2012 2:14 pm

saildrive2001 wrote:Thanks guys I will go to the bike shop today.
Roger, have you got any details that you can share about your choke mods? Although I am trying to keep my car as original as possible the choke cable routing is really bad. I have bbeen thinking of making a better arrangement than the stock item.


Hi Keith,
I did the mod soon after I got the car back in the 70's because I didn't like the loop through cable arrangement either.
It's basically a mechanical linkage which operates both choke levers from a single cable. The connecting rod pivots on aluminium angle brackets which mount on the carbs using the same dowels and screws as the original cable abutment brackets. It's probably somewhat over-engineered for the job and one day I may make it a bit more lightweight - we'll see!
I've used a solid wire cable (heater valve type) which does ensure that the chokes are fully off when the knob is pushed in but does make it a bit stiff to operate due to the tight bends - might be better with the original flexible choke cable but I don't have one now to try it. Anyone know if they are available with the correct knob to match the original ?

Couple of pictures below which may give you a better idea than my description. Let me know if you need any more info.
Attachments
Choke linkage 006.jpg and
Choke linkage 004.jpg and
Choke linkage 005.jpg and
Roger
S4 DHC
oldelanman
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1969
Joined: 02 Jan 2008

PostPost by: saildrive2001 » Wed Oct 31, 2012 2:23 pm

Thanks Roger the pictures were great. Just add some lightening holes to the brackets & arms to make it a Lotus design.
Keith Marshall
69 S4 SE DHC RHD Original owner
saildrive2001
Fourth Gear
Fourth Gear
 
Posts: 597
Joined: 29 Oct 2003

PostPost by: oldelanman » Wed Oct 31, 2012 2:27 pm

saildrive2001 wrote:Just add some lightening holes to the brackets & arms to make it a Lotus design.


Can you still buy UNF holes or would I have to use metric ? :roll:
Roger
S4 DHC
oldelanman
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1969
Joined: 02 Jan 2008

PostPost by: saildrive2001 » Wed Oct 31, 2012 5:09 pm

We still have UNF holes in Canada although they are harder to find than UNC ones.
Keith Marshall
69 S4 SE DHC RHD Original owner
saildrive2001
Fourth Gear
Fourth Gear
 
Posts: 597
Joined: 29 Oct 2003

PostPost by: SonnyS » Wed Oct 31, 2012 7:51 pm

saildrive2001 wrote:...but it still is sticky when opening the throttle
Is this with the hood on?

saildrive2001 wrote: ...the throttle returns without any hesitation or sticking
Is this with the hood off?

If yes to both. Could youre cable be too long and alignment is being compromised by the hood?

Regards - Sonny
User avatar
SonnyS
New-tral
 
Posts: 14
Joined: 13 Apr 2012

PostPost by: twincamman » Wed Oct 31, 2012 9:06 pm

you just twigged my mind ----IM out to install my rev limiter rotors in both T,C, motors
dont close your eyes --you will miss the crash

Editor: On June 12, 2020, Edward Law, AKA TwinCamMan, passed away; his obituary can be read at https://www.friscolanti.com/obituary/edward-law. He will be missed.
User avatar
twincamman
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3175
Joined: 02 Oct 2003

PostPost by: saildrive2001 » Wed Oct 31, 2012 11:08 pm

The problem is the same with & without the hood closed. It feels like the twists of the wire are causing the problem under throttle opening.
I have just got today a teflon coated inner & a teflon coated outer from a bicycle store as well as making a new bulkhead fitting from a stainless bolt. These changes seem to have improved the situation but will wait to pass further judgement until I get out for a drive. Could be a few days yet as we are still getting rain from Sandy.
Keith Marshall
69 S4 SE DHC RHD Original owner
saildrive2001
Fourth Gear
Fourth Gear
 
Posts: 597
Joined: 29 Oct 2003

PostPost by: pamitchell » Wed Oct 31, 2012 11:54 pm

You could also consider using a throttle cable kit from the Hot Rod suppliers like Lokar. I fitted one on my LHD S4.
Very smooth action and the components are meant for engine compartment conditions.
http://www.summitracing.com/search/bran ... roductName
Phil
1968 S4/SE FHC 36-7936
pamitchell
Third Gear
Third Gear
 
Posts: 332
Joined: 11 Sep 2003

Total Online:

Users browsing this forum: Phil.C60 and 13 guests