Hi , I am nearing competion of a complete rebuild of a 1968 Thunderbolt, my problem is after fitting the kickstart spring which was a bit of a job at first but eventually on and fitted square, the cover was then fitted
and engine kicked over with plugs out after a few kicks the kickstart was sticking sometimes --- so I remove the cover and see that the spring has crept down behind the plateand engine case , has anyone had this problem and if so how to rectify I have bought 2 other springs with the same result , I also tried putting a spacer on the shaft behind the spring to stop it going behind but this stops the outer cover fitting flush.any help appreciated TIA
There's a lot of rubbish springs on the market. I find the only ones which are made correctly are from srm. With others the spring wire just bends and doesn't coil.
is the spring plate ok? the bent over top bit can wear or bend.
On some bikes there is a spacer in between the spring and shaft as when the spring turns it can move around, its just a case of trial and error , just long enough and not too short. Spacer needs a slot cut in it but not all the way through
Hi AllanG , As Stated I have bought 2 springs with the same results but will try SRM but as you say the springs do not function properly and are rubbish thanks for speedy reply
Hi Chas , The plate was ok but I bought a new one just in case , Yes the spring is moving down around the back of the plate and is trying to push the plate off the locating flats I fabd a washer for behind the plate but could not get the outer cover to fit as it was holding it off not to sure on what your saying about cutting a slot---thanks for speedy reply .
google , kickstart spacer there are a few examples on there.
some plastic, I favour, others Ally.
basically it stops the spring from distorting and moving.
Im yet to start rebuilding the A50 so bits in boxes everywhere, have been over 2 years but you should be able to design something to keep it in place.
Quote from: chaz on 10 Dec, 2023, 14:06
google , kickstart spacer there are a few examples on there.
some plastic, I favour, others Ally.
basically it stops the spring from distorting and moving.
Im yet to start rebuilding the A50 so bits in boxes everywhere, have been over 2 years but you should be able to design something to keep it in place.
With a decent quality spring you wont need to design anything.
Hi Allan G, I am sorting a spring ,will give srm a bell thanks.
Hiya, I may be taking this off down the wrong track but my experience was that I had a sticking kickstart every 5-6 swings.
When I searched through this forum, the consensus seemed to be, yeah they do that. I took a close look at the mechanism where the Kickstart ratchet meshes with the pinion. it appeared to me that every so often the teeth of the 2 items were meeting with the tops of the teeth hitting each other straight on and jamming. i tried filing the first tooth on the ratchet with a bit more of an angle but that didn't work and I wouldn't advise that. Then I bought a new pinion and that helped a little but not much.
For the moment I am living with it but it drives me nuts! I guess the next move is to buy a new ratchet and shaft. Expensive I think.
I didn't notice any displacement of the spring though and without actually taking the cover off I'm struggling to imagine how that would jam it.
I'll be very interested to see if your new spring fixes the issue. I will have to rethink my own investigations.
I'm not sure this is very helpful but hopefully thought provoking?...
Best of luck, Glenn
i always find that if you pull the spring in tension with the right hand attached to molegrips on the spring tap and the left hand holding a screwdriver push the spring tab plate towards the engine . it helps to felt tip the flat for alignment . then with your other hand place a long thin screwdriver on the left side where the spring catches and lever it out of the way and push on the plate . with another hand spare you can easily pull the spring over to the left by using a suitably sized screwdriver as a lever on the spring then push with your right hand molegrips. ten minute job.
:) :) :) :)
jamming kick starts not unusual.
When you kick it over dont let the kick start come all the way back to the to, until it starts thus the cam and cog will remain in mesh
Clutch spring. I find that if you put the anchor washer in place then put a jubilee clip around the shaft tight up to washer, the washer stays correctly butted up whilst you fit the spring, Wiich is relatively simple with a length of nylon cord. (para cord)
Mike 8) 8) 8) 8)
Hi,
There was a previous post about this with a design for a tool to help. Try the search for 'kick start spring'.
Dave.
solved my kickstart issues by greasing bushes and rubbing down high spots, then arc welding the half tooth , recutting the slot and filing the weld to make a higher tooth than standard. it doesnt have to be factory finish but high enough to push and line up the ratchet with the second tooth.
[quote author=GlennA65 link=topic=17951.msg97161#msg97161 date=1702313974 it appeared to me that every so often the teeth of the 2 items were meeting with the tops of the teeth hitting each other straight on and jamming.
[/quote]
Hi Glenn. I had exactly the same problem on a 1968 Bonneville that I was rebuilding. It turned out to be caused by the new kickstart pinion that I'd bought. The teeth on the new pinion hadn't been cut as per the original design. The new pinion had straight cut teeth that ended in a small flat surface - basically it looked like a standard gearbox pinion. It would jam every two or three uses of the kickstart lever. The proper profile for the teeth is much more complex. The correct profile isn't straight, but curved - the faces of the teeth are convex and end in a knife edge. I contacted the supplier of the new pinion I'd purchased and he said that manufacturing a pinion with curved teeth is very complicated and the only company that used to do it (based in Coventry) has now stopped doing that sort of work. He managed to find a few of the pinions with the correct teeth profile so I bought a couple. I think your best option is to find a good original pinion, even if it looks a bit worn.
Regards
Tony
A65 pinions don't tend to be a problem. However ensuring the first tooth meshes properly and either misses or allows the half tooth to push the pinion to the right position so that the first full tooth engages properly is crucial. On some occasions I have had to file a bit off the half tooth when using some of the NOS quadrants I bought some years ago. Not much but just enough so that it misses at the point it needs to. With that I've yet to have a kickstart jam since doing it.
Quote from: Tjwood on 13 Dec, 2023, 12:14
[quote author=GlennA65 link=topic=17951.msg97161#msg97161 date=1702313974 it appeared to me that every so often the teeth of the 2 items were meeting with the tops of the teeth hitting each other straight on and jamming.
Hi Glenn. I had exactly the same problem on a 1968 Bonneville that I was rebuilding. It turned out to be caused by the new kickstart pinion that I'd bought. The teeth on the new pinion hadn't been cut as per the original design. The new pinion had straight cut teeth that ended in a small flat surface - basically it looked like a standard gearbox pinion. It would jam every two or three uses of the kickstart lever. The proper profile for the teeth is much more complex. The correct profile isn't straight, but curved - the faces of the teeth are convex and end in a knife edge. I contacted the supplier of the new pinion I'd purchased and he said that manufacturing a pinion with curved teeth is very complicated and the only company that used to do it (based in Coventry) has now stopped doing that sort of work. He managed to find a few of the pinions with the correct teeth profile so I bought a couple. I think your best option is to find a good original pinion, even if it looks a bit worn.
Regards
Tony
[/quote]
Thanks Tony, I forgot to mention that. Yes that is why I bought a new pinion, because the tops of the cogs were flat and the replacement was more more profiled. I still think it had a slight flat on it. As I said it has helped but no solved it. maybe I 'll get a file to the first couple at least next time I open that area up. I'm interested in what Eddie says too. Me messing about with a welder on precision teeth, what could possibly go wrong!
Hi All, Thanks for all your usefull, fast replies--- I purchased a new SRM spring and fitted it and it seems to be working ok some very interesting helpful answers there which will come in handy if a problem arises later
Once again thanks for all your help .
May I wish you all a very merry christmas and a happy and healthy new year