@TonyMNo1 - I got a spring from a local hardware store, I can check the dimensions when I get home (down in Cornwall until Tuesday next week) but it was nothing like as "strong" as a main stand spring. My understanding is that the spring doesn't have to offer exactly the same resistance as the value but it has to be strong enough to pull the cable back to the extended position. I think I have a spare spring in the garage, as I'm sure I would have brought a couple of them. From memory they were about a couple of £ each.
I've been out into the garage and now fitted the spring mechanism modification to the 1260 EXV. I used a spring diameter size, that was very close to the diameter of the end plug on the cable. It meant I had to 'wind on' the spring carefully so as not to damage the cable, to which I then added a washer fitted on the inside of the plugged cable end. I had to saw cut a small slot in the washer so that I could pass it over the cable and then closed the gap with pliers, thus trapping the plugged end outside of the spring, stopping it disappearing back into the spring bore. (I've attached a couple of photos for better clarity) I've cycled through the start/stop sequence several times now with no errors, but saw something interesting. At one point through the cycle, the spring fully releases and gives the cable the maximum length, whereas for probably 95% of the cycles it doesn't, staying under slight tension. I'm unsure why, but it still seems to function OK. I've also started the bike and run it up several times still with no errors on the dash and also with the spring under slight tension. When I blip the throttle the spring tension increases, causing the spring to curve backwards towards the spring tube, mirroring the flap valve closing to some extent. It then releases once again as I cut back on the throttle, remaining under slight tension. I'm unsure what this might mean, so any thoughts/opinions/advice, would be appreciated. All seems satisfactory, so pending a ride out with this minor modification, in order to see what difference, if any, it actually makes. Other than a slightly deeper exhaust note, with greater 'barking' when the throttle is applied, to higher revs, as yet nothing obvious other than, assuming that I've done the job well enough, no sodding sticking EXV in the future.....
The slight difference in exhaust note is about the only change I noticed. Apart from the knowledge of knowing the valve won't stick!
If you mean about the spring changing when you open the throttle, that is just allowing the wire to do what it should do as it would normally open the valve with revs. Nothing to worry about. If will be slightly louder because it’s alsways open, esp 4-5k revs. Some find it also sorts out the fluffy ness a bit at that rev range
My solution on the mod after the idiotic routing finally rotted & broke the inner cable. I used a handlebar lever cable adjuster, spring & solder-less nipple. The result is a much nicer/deeper exhaust note off the stock system at the possible expense of being a bit “lumpy” around the 30/40 mph mark which, having just returned from a trip down the west coast of Ireland, I don’t even notice anymore.
