MU Choke cable not returning

[Richiep]

Hi all,

 

Last year I had the choke cable to the Metering unit snap (the one to the inlet manifold was still ok) so I sent it off to have the cables replaced.

 

Got it back and refitted it to the car, and it pulls the lever on the MU fine, but isn't stiff enough to 'push' it back again when I push the choke knob in inside the car. Very frustrating as I need to pop the bonnet and manually move the lever each time when it has warmed enough to put the choke back in!

 

I spoke to the place that fitted the new cables and they have suggested lubricating the cable, which I have done but not for its whole length yet (but plan to do) or to send it back for them to replace it with a 'solid' piano type wire, rather than the stranded one it is now. The new one is more like bicycle brake cable (very flexible), but the original one was still a stranded one, but did seem to be a bit stiffer so it should be able to still be that type? The 'solid' type apparently doesn't have a great bend radius.

 

Any suggestions would be very helpful.

 

Thanks and regards,

 

Richard

[TriumphV8]

A spring at the lever arm might help.

 

Anyway a not fully returning lever is a pain

and horrible for performance.

[RobinTR6]

Same problem cured with spring assistance at lever arm, co spring on cable wire between lever arm and outer cable, used small washer at outer cable end to stop spring riding up it, pence.

[astontr6]

Richard,

 

I have had a look at mine which is original and the outer spiral metal jacket is heavy grade and the control wire is also made up with heavy grade stranding to make it stiff, so I suspect that the repro one is not manufacured to the same spec. Another job for the TTR QA Team? I hope you send them details?

 

Bruce

[JohnRoberts]

Hi Richard

 

You could use a bicycle gear cable which is as a much steeper helix angle

 

Regards JohnR

[Tim D.]

I ended up using two separate cables for the mu and the idle adjustment. I chose cables that had a solid wire core (available on eBay) and they worked excellently. The repro one I had was a disaster. It was not stiff enough and the turn to lock mechanism didn't work which meant the cable twisted and eventually failed. And it cost £70.

Tim

[Richiep]

Hi All,

 

Thanks for all the replies.

Given Tim's experience, I'm glad I didn't go for the repro one!

 

Bruce, I suspected that must have been the case.. with the original being much stiffer. Good to know I wasn't imagining it!

 

I like the idea of getting a stiffer cable fitted, possibly the bicycle gear cable, but not sure I'd be able to do that myself.

Looks like the most likely option is the additional springs, either one on the cable wire, or one on the lever arm.. I guess the difficult but is knowing what spring to get..? Any help with that would be appreciated..

 

Thanks again,

 

Richard