G: Gearbox (Twin) G87/1 Kickstart Return Spring Replacement

[Cyborg]

Vic,
What’s the story on the outrigger plate on the end of the crank? I’m assuming you tossed the oil feed quill in favour of something that seals better. Also the alloy plug just to the rear of the 1/2 time pinion?

 

[delboy]

The original question was, whether the spring was correct?
To me, it looks that the "U" end has been formed incorrectly.
Regards, Delboy.

 

[Graham Smith]

I got two springs from The Spares Company, and they're identical.

Maybe they have a faulty batch?

 

[Bill Thomas]

Don't think so I have had mine for some years with the closed end.
Just stick one on !.
I like to carry a Bungy strap , That would get you home.

 

[Bill Thomas]

That's funny, just seen on Ebay Kickstart spring with both ends closed off !,
He is one our top blokes from years ago and sells NEW Vincent bits .

 

[oexing]

That alu plate over the half time gear is a dam for having a higher level of oil in the timing chest, so the old drain hole was plugged and a new hole a bit higher up is meant to raise the level - or so I believe. Time and road tests will tell but this will be not before next year. The oil feed into the crank end is a hardened and spring loaded turning with a 45 degrees taper sitting on the crank end, no extension into the crank then. I have seen that elswhere, don´t remember but liked that a bit - to be tested again.

Vic

 

[greg brillus]

The long open end of the spring is so you can install it on the top peg easily.........The kickstart levers bounce up and down quite a lot on road bikes, the newer kickstart levers are heavier than the originals making the issue worse. Not sure about a road bike but on a racer blanking off the lower timing case return hole like Vic has done results in massive amounts of oil churning around in the timing chest, this can make oil leaks from anywhere in that area worse........It is a total waist of time as none of this extra oil gets to the cams and followers where it is needed most.

 

[oexing]

Well, Greg, we´ll see. Massive oil around there is just my plan and I don´t expect no oil mist to get to followers then. Any lathe and gearboxes like an certain oil level so why not - when all else is as should be .

Vic

 

[The VOC Spares Company Limited]

The open end of the spring was as a result of many requests so that the springs could be changed without removing the cover several years ago.
The sharp bend on the open end of the spring was removed in consultation with the spring manufacture to conform to "best practise" to relieve the possible failure stress point. this was changed about 18 months ago.

 

[BigEd]

For what it is worth I had two springs break over a lot of miles. My guess is that the spring was stretched too far when at the bottom of the kickstart stroke. After the second one broke I fitted the loop from the end of the broken spring to the new spring to make it longer my theory being that if the spring was stretched less it was less likely to break. The (obvious?) downside is that the kickstart isn't held up to the stop quite so firmly but this didn't seem to have an adverse effect. How easy it is to be able to change the spring without removing the gear cover I can't comment on as it is something I have not tried.
The revised profile of the bend on the open end will most likely have improved things considerably.
I have now removed the kickstart and all the attendant parts so the chance of the return spring breaking is reduced to zero as I have an electric start fitted. The downside of this is the cost. A new spring is easy on the wallet but the electric start is easier on the leg and knee.