Replacing choke cable

[Jonny TR6]

Whilst overhauling my fuel system I’d like to replace the choke cable. The original was very frayed and therefore I had to chop it back a tad to get it through the hole in the bolt. This has given me insufficient pull on the choke knob to enable a decent opening of the butterflies.

I can’t seem to find the cable without the full knob assembly etc. I was hoping to pop just a new length of cable in.

However, whilst typing, the idea that I can just cut the sleeve back a bit and that will give me more cable, popped into my head. 

Any reason I can’t ?

[RogerH]

53 minutes ago, Jonny TR6 said:

Whilst overhauling my fuel system I’d like to replace the choke cable. The original was very frayed and therefore I had to chop it back a tad to get it through the hole in the bolt. This has given me insufficient pull on the choke knob to enable a decent opening of the butterflies.

I can’t seem to find the cable without the full knob assembly etc. I was hoping to pop just a new length of cable in.

However, whilst typing, the idea that I can just cut the sleeve back a bit and that will give me more cable, popped into my head. 

Any reason I can’t ?

Hi Jonny,

I've not had the chance to play with the TR6 choke cable but have remade TR4A choke cables.  I used bicycle brake cable and solder it in place.

They are usually Stainless steel so the flux needs hunting down.

If it can be made - it can be repaired.

 

Roger

[Jonny TR6]

16 minutes ago, RogerH said:

Hi Jonny,

If it can be made - it can be repaired.

 

Roger

Thanks Roger - I also generally live by the same rule !

[Jonny TR6]

1 hour ago, Jonny TR6 said:

However, whilst typing, the idea that I can just cut the sleeve back a bit and that will give me more cable, popped into my head. 

Any reason I can’t ?

Of course it worked ! why did I even bother posting...

Anyway - it's there for anyone who is having a brain fade like me.

Too many cherry liqueurs.

[PodOne]

Carbs or PI different solutions possible from repair to replace with a better design.

Andy

[Jonny TR6]

PI Andy - must admit it’s not the best design, but does the job. Using an underslung throttle lever system, so the choke locates at the front of the cylinder bank and operates all the butterflies via the centre spindle.

[John L]

If you get stuck, Martin is remaking a lot of PI connected stuff,  Martin AKA Fred Millturn  on here on the forum.

John

[OldBob]

2 minutes ago, Jonny TR6 said:

PI Andy - must admit it’s not the best design, but does the job. Using an underslung throttle lever system, so the choke locates at the front of the cylinder bank and operates all the butterflies via the centre spindle.

The TR6 PI 'choke' cable isn't really a choke at all - its a pair of cables that provide mixture enrichment on the metering unit through the long cable - plus a little throttle movement on the short cable.

If your throttle cable has ended up a bit short Johnny it shouldn't affect the starting, just the ease of running until it warms up.

Bob

[Jonny TR6]

Thanks Bob - hadn’t realised that. It seemed that it was only operating the butterflies and I was scratching my head on what was happening with the fuel side of things.

Any parcels arrive recently? I popped a PM to you explaining what was in the post.

[PodOne]

Hi Jonny 

You can remake the OEM PI dbl cable using bike brake cable.

The aftermarket ones allegedly poor quality and fail but having remade mine myself I then swapped to one of Martins (Fred Millturn) redesigns along with some of his other items which works better and easier to adjust.  

Andy

[iani]

3 minutes ago, PodOne said:

Hi Jonny 

You can remake the OEM PI dbl cable using bike brake cable.

The aftermarket ones allegedly poor quality and fail but having remade mine myself I then swapped to one of Martins (Fred Millturn) redesigns along with some of his other items which works better and easier to adjust.  

Andy

We fitted one of Martin's CP choke cables to my Mk1 2.5PI Estate (homage) today, works a treat, I already use the 2nd cable part of this on my Mk2 PI Saloon to solve a broken cable issue to the MU on that car. Martin is an extremely helpful supplier.

Ian

[PodOne]

Just now, iani said:

We fitted one of Martin's CP choke cables to my Mk1 2.5PI Estate (homage) today, works a treat, I already use the 2nd cable part of this on my Mk2 PI Saloon to solve a broken cable issue to the MU on that car. Martin is an extremely helpful supplier.

Ian

+1 Martin's great to deal with customer service second to none.

[iani]

Just now, PodOne said:

+1 Martin's great to deal with customer service second to none.

He drove parts over to me three times in the last few days, his service is incredible.

[Jonny TR6]

In discussions with Martin at the mo re throttle linkages - super knowledgeable and helpful and his bits look top notch.

Also gave me an interesting heads up on Molykote, which I’ll update the other thread on…

[Jonny TR6]

On 12/29/2023 at 5:27 PM, John L said:

If you get stuck, Martin is remaking a lot of PI connected stuff,  Martin AKA Fred Millturn  on here on the forum.

John

Funnily enough I did contact Martin…

one new throttle linkage with correct linkages to the spindle levers (rather than ball joints), new choke and MU cable, a new throttle cable and 2 new Superpro throttle pedal bushes later and the car actually starts !

As others have said, he was super helpful, gave me lots of good advice and what he doesn’t know about the PI system isn’t worth knowing.

The car now idles at 600 rpm if I want it to, throttle pick up is sharp and there’s no slop in the countershaft bearings (went for ball bearing version). 

I haven’t done a test drive yet, or in fact properly balanced the butterflies, but at least I can get the car to idle nicely.

Thanks to all for pointing me in his direction.