Throttle Slack on my Tiger.

[Alex.]

Hi Guys,

I'm starting to get to grips with my Pinto'd Tiger and have just had BD Engineering setup the carbs (DCOE 45s) and regain the lost horses. Andy really does know his stuff.
But ever since I've driven the car, it is really hard to engage the throttle smoothly. The slightest bump on a light throttle has me jerking and kangarooing down the road! There is no slack in the cable at all and adjusting it just moves the pedal, as there is no return spring on the pedal itself.

Should there be a return spring? Do I just need to learn how to drive properly?
Help me SKCC, you're my only hope... It's doing my head in!

Alex.

[greenwoo]

maybe take pics of both ends so that we can see your setup and be better placed to help......

[SJLB]

Hi Alex
not sure if this will help but I've experienced a similar thing although it wasn't with a carb set-up. On my old Westy the throttle cable wasn't very smooth and I found it difficult to accelerate smoothly at lower speeds, if I pressed the pedal lightly noting happened and if I pressed harder it would be too much and I'd shoot off. The cable seemed fine when I disconnected it and checked it over but the problem was the angle of the bracket by the throttle body, it wasn't straight so the cable was rubbing on the side of the cover where if exited. In the end I had to alter the bracket and get a longer cable so it had no bend near the throttle body. Might be worth checking the routing of yours and see if it can be improved. If you need a longer cable you can get one made to order from here https://www.venhill.co.uk/

[Alex.]

maybe take pics of both ends so that we can see your setup and be better placed to help......

I should be able to take some pick later today, I'll see what they can show.

Alex.

[Alex.]

Hi Alex
not sure if this will help but I've experienced a similar thing although it wasn't with a carb set-up. On my old Westy the throttle cable wasn't very smooth and I found it difficult to accelerate smoothly at lower speeds, if I pressed the pedal lightly noting happened and if I pressed harder it would be too much and I'd shoot off. The cable seemed fine when I disconnected it and checked it over but the problem was the angle of the bracket by the throttle body, it wasn't straight so the cable was rubbing on the side of the cover where if exited. In the end I had to alter the bracket and get a longer cable so it had no bend near the throttle body. Might be worth checking the routing of yours and see if it can be improved. If you need a longer cable you can get one made to order from here https://www.venhill.co.uk/

I don't think that it is a cable routing issue, the operation is smooth throughout including the initial take up. It's just that going over a bump moves my foot, which alters the amount of throttle demand.
It is similar symptoms to having no slack in the twistgrip on a bike, so my first thought was to introduce some slack, but loosening the cable only alters the position of the pedal as there is nothing pulling the pedal back to the initial rest position.

I was just wondering if our local cohort of Tiger owners have had this issue and if there is a solution.

Alex.

[Nash]

Alex, there should be a spring return in the linkage. You need some resistance on the throttle even when there is “slack” in the cable. When you back off the throttle it should “snap” shut.

[greenwoo]

ahead of pic's ( in case there's anything weird on the length pedal/carb end.....i'd agree with Neil.
As long as the mechanism on the carbs translates into enough travel at the pedal ( ie/ the action on the pedal is not too short between closed and WOT) then it's a question of balancing the feel of the pedal with a return spring.
You may need to play around to find the right resistance, too stiff and it'll feel horrible, but just right and it should be possible to kind of brace your foot against that resistance as you're driving, so that going over a bump doesn't alter the pressure/travel.

[Fury1630]

The Fury was a little like you describe when there was too little pedal travel, so it was too sensitive.

[Martin S]

Put a stronger spring were the cable meets the pedal...done it before..that should cure it...martin

[Alex.]

Put a stronger spring were the cable meets the pedal...done it before..that should cure it...martin

That was my first thought, as there is no spring at all. The only connections on the pedal are the cable and the mounting pivot half way down.

20180608_153436 by Alex Taylor, on Flickr

The cable inner between the pedal and the cable outer is the slack I put on earlier.

Alex.