General => Douglas Motorcycles - General Discussion => Topic started by: Red on 23 Feb 2019 at 15:41

Title: Aero 600 Kick Start Return Spring
Post by: Red on 23 Feb 2019 at 15:41

I'm having problems fitting a new kick start return spring to my Aero 600. I obtained a new spring from club spares and fitted it as shown in the attached photo. Problem is I can't get sufficient pre-load on the spring to get the kick start to fully return. There seems to be only two studs where the outer part of the spring can be attached. To fully wind it a further 360 degrees results in the coils binding (in fact long before I reach that point) and I am sure the spring would break as soon as the kick start was used. It could also be attached to the other stud - at the 1 o'clock position looking at the photo of the outer gearbox cover, but coil binding is still a problem. Ideally if it could be attached to the stud at the 9 o'clock position that would seem ideal but the outer cover is not recessed for this purpose. I've also attached photos of the old broken spring and the new spring from club spares. If the new spring had the inner attachment in the same poistion as the old spring then again I think there would be sufficient pre-load. Eddie T very kindly suggested making up a bush with a larger diameter to fit on the kick start spindle where the spring wraps round. I've done this and this part of the spindle now has a diameter of 22mm and whilst this has made some improvement the kick start still does not fully return. Anyone got any other suggestions. Does the new return spring look correct? Any help will be very much appreciated, Thanks

Title: Re: Aero 600 Kick Start Return Spring
Post by: Red on 28 Apr 2019 at 12:54
In case anyone should still read this old post the problem has now been resolved. The spring provided by Club spares turned out to be for the 3 speed pre-war box. Another club member (Len Boydell) very kindly dismantled two 4 speed gearboxes he had in stock, which he thought had not been apart in the past 50 years. With these two return springs and my original broken spring we were able to obtain a good sample to copy and Club Spares had some made up. This I have now been fitted to my gearbox and the kick start works perfectly. My thanks to Len and our Club Spares man Dick Bradley.