Vic787 Posted November 19, 2014 Report Share Posted November 19, 2014 Not the food type but the twins fitted to my TR4. Throttle is sticking and needs a blip on the pedal to settle the revs down. It races at about 500 revs above tick over. If I disconnect the spindle between the carbs, both return immediately to tick over. I have stripped and rebuilt them over the years and tried, what I think almost everything but on reassembly, no different and still needs a sharp tap on the accelerator pedal to regain tick over. I am at the point of thinking the spindles need renewing. What are your thoughts please. vic Quote Link to post Share on other sites
Fireman049 Posted November 19, 2014 Report Share Posted November 19, 2014 (edited) Hi Vic ~ Are your jets 'centred'? Remove the two dashpot dampers and fully raise the pistons then let go and see if they return with a positive 'click' onto the bridge. If not then raise the jets until they are level with the bridge slacken the jet gland nuts and move the jet assembly until both pistons lie flush with the bridge then retighten the jet gland nuts. Raise the pistons and make sure they contact the bridge with a positive 'click'. Hope this may help? Cheers ~Tom. Edited November 19, 2014 by Fireman049 Quote Link to post Share on other sites
graeme Posted November 20, 2014 Report Share Posted November 20, 2014 Hi Vic, My 4A had a similar problem some time ago. I discovered that the ball on one of the throttle linkages was damaged/scored. I took it off and dressed it up with a needle file with the intention of replacing it later but it has been fine since. Cheers Graeme Quote Link to post Share on other sites
TriumphV8 Posted November 20, 2014 Report Share Posted November 20, 2014 Throttle is sticking and needs a blip on the pedal to settle the revs down. Sounds like the problem is in the linkage before the carbs and not in the spindles etc. in the carbs. I would go backwards and disconnect other things in the lever connection backwards to the throttle pedal. Connect the spindle between the carbs with the next joint and leave the rest unconnected. If it sticks the defect must be between the carbs and the opened connection. If not go further backwards until you include the faulty thing and the system sticks. Quote Link to post Share on other sites
Lebro Posted November 20, 2014 Report Share Posted November 20, 2014 +1 on above answer Quote Link to post Share on other sites
ianc Posted November 20, 2014 Report Share Posted November 20, 2014 Inclined to agree with Graeme and Andreas - the balls in the linkage wear to very odd shapes! A few months ago on the Forum, Pete Wigglesworth was offering brand new, complete joints for the throttle linkage - I bought some as insurance. Perhaps he has some left? Ian Cornish Quote Link to post Share on other sites
stuart Posted November 20, 2014 Report Share Posted November 20, 2014 (edited) On H6 carbs its often the return spring on each spindle next to the body of the carb that has started to lose its tension.Undo the clamp (4BA) and wind the spring round the shaft another half a turn by turning the clamp then re-tighten the clamp.(Sometimes they may need a full turn.) Stuart. Edited November 20, 2014 by stuart Quote Link to post Share on other sites
Allan Westbury Posted November 20, 2014 Report Share Posted November 20, 2014 i agree with the linkage theory. In my case the nut on the carb spindle that the linkage fits into ( very scientific description- apologies) was coming loose allowing air ingress which bu**ered the fuel mixture and gave higher tickover. These nuts should have a tab washer to stop them coming undone. Quote Link to post Share on other sites
LGFromage Posted November 21, 2014 Report Share Posted November 21, 2014 My 4A had a similar idle speed problem which was resolved when I fitted a separate limit to the bellcrank movement which then allowed the carburettor spindles the freedom to find their own way to close. Whilst the 4 linkage arrangement is different from the 4A the same principal may apply. Tim Quote Link to post Share on other sites
Vic787 Posted March 30, 2015 Author Report Share Posted March 30, 2015 (edited) I know this has taken some time to reply but in the meantime I have been trying to sort out the problem. I have eventually completely stripped down and reassembled all the parts. I did find that the return spring on the crank where the rod enters the engine bay was missing. Plus new linkage on both accelerator and choke all is well Thanks everyone your advice is always welcome Vic I said all is well, however with regard to your post Tom, the dashpots are very clean now but only one drops with a click on the bridge, the other is a dull thud and does not seem to fall as quickly. The engine runs well although not road tested yet. Edited March 30, 2015 by Vic787 Quote Link to post Share on other sites
stuart Posted March 30, 2015 Report Share Posted March 30, 2015 The pistons need to drop the same, check the base of the pistons to make sure they are both the same, some have a nylon buffer which can make a difference to the sound when it hits the bridge. Whatever though they must both drop the same check the centring of the jets.. Stuart. Quote Link to post Share on other sites
Lebro Posted March 30, 2015 Report Share Posted March 30, 2015 Sounds to me as if one of you jets is not centred correctly. Bob Quote Link to post Share on other sites
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