To all helpful individuals out there,

I have a set of R1 carbs on my zetec and the throttle linkage has been somewhat annoying for some time now.

There is little graduation in the throttle travel, i.e its either off/on (exaggeration) and only occasionally in between. The springs on the body are standard and quite strong but it very rarely returns all the way to idle. All i want is an easy pedal which will allow me to smoothly apply power out of corners and not plant it all down and let the rear end shoot out!

Any help will be gratefully received,

Chaz

May or may not help, but when I was building my car I had a similar problem and found that the bolt through the accel' pedal in the pedal box was slightly too tight, I slackened it off and it was all fine

sorry if this doesnt help i'm not a bike engine guru at all

would changing the springs help?

For a second I thought this was another awaiting GTS parts post

anyway, sounds like you need to alter the throttle cable connection on the pedal to you have less leverage and more travel, the more the better. I'd also remove the springs and see if there's too much friction in the carbs, perhaps the linkages need realigned. Certainly sounds like it if you say it’s sticking (quite a dangerous situation). Disconnect the cable also and check each part for being too tight. You should only need a small spring the return the butterfly’s. Once it reliably closes then the only spring force required is to lift the pedal up.

Are you sure this isn’t carb icing? Does it get worse after its been running for a few minutes?



[Edited on 14/7/09 by Mr Whippy]

for the travel in the pedal, i think you may need to look at moving the cable nearer to the pivot point of the pedal

R1 carbs (well at least mine) originally have a throttle return cable on. You could put one on if you haven't already.

However it sounds like this problem has become worse? If so then this solution won't really help the situation long term.

James

I know the problem is defiantly at the carb end. I have quite a few inches of travel in the accel pedal, thats seems to work fine without the cable attached.

Linkages aligned, sounds like a big job!

I am slightly suspecting the throttle wire to being abrasive to the inside wall of the throttle cable metal shroud. The cable turns around 120 degrees before attaching to the throttle body. Is this turn to much? I have tried WD40 on all the moving parts, which helps to some degree but doesn't solve the problem.

Any more ideas?

WD40 is not a lubricant! "WD40" = "Water Dispersant 40" - I suggest that you try a light oil.

Apart from that, most bike carbs had 2 throttle cables - one to open the butterflies, and one to close them. Many people (including me) have put a strong-ish spring on the 'close' side to help to shut the carbs.

HTH,
David

fit a return spring,

Show us a photo of the linkages at both ends of the cable for more helpful replies

Attaching a photo would be the ideal solution and unfortunately i am currently quite a distance from my car.

Thanks to all those who have helped.

I know your all guessing but with the level of experience on here i'd imagine your bang on with the return spring idea!

Hi there
Speak to Steve at Bogg bros
As already mentioned you need to relocate the connection of the throttle cable at the pedal end.
I put R1 carbs on my old 205 and he rewelded a cable connector on my 205 pedal and it was all sorted,i also needed to fit either a stronger or an extra which i did return spring on the linkage end.
Spot on after that.

I'd also try fitting a cam'd throttle arm (the type the throttle cable "wraps around". They give an exponential throttle opening so more sensitivity at small throttle pedal openings but full wack at full wallop. They are fitted to many TBs including Rover 200 ones IIRC....

Like

If you suspect the cable rubbing inside then replace, some are nylon lined and don't like lubrication.

Of topic but WD40 is a lubricant, it's just called water dispersant #40, lifted from the site:

CLEANS: WD-40 gets under dirt, marks and grease making it easy to wipe away. It also dissolves adhesives, allowing easy removal of labels, tape, and stickers


PROTECTS: WD-40 protects metal surfaces with corrosion-resistant ingredients to shield against moisture and other corrosive elements


LUBRICATES: WD-40's lubricating ingredients are widely dispersed and hold firmly to all moving parts


PENETRATES: WD-40 loosens rust-to-metal bonds and frees stuck, frozen or rusted metal parts


DISPLACES MOISTURE: Because WD-40 displaces moisture, it quickly dries out electrical systems to eliminate moisture-induced short circuits. Turn the power off before you spray

It's a fairly useless lubricant, whatever they say! It's better than leaving the metal surfaces dry, but that's about as far as it goes. It is a splendid cutting lubricant for aluminium though!

As for posting pictures - I was at work! But search is a wonderful thing...

Linky-do

There were quite a few threads on this topic, and some very good solutions, so I recommend some searching and browsing.


[Edited on 14/7/09 by David Jenkins]