Scooterotica

^... MBD sells a modern version of this very tool

bristolmod wrote:
It COULD be that the internal lever is bent and not showing any signs (yet) of stress or fracture. That would mean that the operating mechanism (i.e. the K/S piston) was not completely parallel with the gear it engages with. Which in turn means that it will "fail" earlier than it should - hence 4 "failed" pistons so far.

Chris

My money is on this: Paneer Indian shaft . New shaft in pre-mod chaincase just jams the piston on the 1st gear before reaching the teeth. If it DID start the engine then the damage to the piston would be wear from the other side of the teeth + you would have heard the grating noise and not gone further. IMHO

Yanker wrote:

bristolmod wrote:
It COULD be that the internal lever is bent and not showing any signs (yet) of stress or fracture. That would mean that the operating mechanism (i.e. the K/S piston) was not completely parallel with the gear it engages with. Which in turn means that it will "fail" earlier than it should - hence 4 "failed" pistons so far.

Chris

My money is on this: Paneer Indian shaft . New shaft in pre-mod chaincase just jams the piston on the 1st gear before reaching the teeth. If it DID start the engine then the damage to the piston would be wear from the other side of the teeth + you would have heard the grating noise and not gone further. IMHO

Ok, so how will I know which shaft to order to replace the one I have?

alanscottj wrote:

Yanker wrote:

bristolmod wrote:
It COULD be that the internal lever is bent and not showing any signs (yet) of stress or fracture. That would mean that the operating mechanism (i.e. the K/S piston) was not completely parallel with the gear it engages with. Which in turn means that it will "fail" earlier than it should - hence 4 "failed" pistons so far.

Chris

My money is on this: Paneer Indian shaft . New shaft in pre-mod chaincase just jams the piston on the 1st gear before reaching the teeth. If it DID start the engine then the damage to the piston would be wear from the other side of the teeth + you would have heard the grating noise and not gone further. IMHO

Ok, so how will I know which shaft to order to replace the one I have?

Missing my point Alan, I meant early shaft in later or mended case, that would result in the teeth barely engaging. A GP shaft would be the correct one.

Missing my point Alan, I meant early shaft in later or mended case, that would result in the teeth barely engaging. A GP shaft would be the correct one.[/quote]

Ok, I know that my side casing is a later one as I bought it new last year (a polished one), the shaft I bought from Cambridge Lambretta, they said it was a GP one. So what do I need to be asking for when I phone a supplier? A late model GP shaft?

Thanks

alanscottj wrote:Missing my point Alan, I meant early shaft in later or mended case, that would result in the teeth barely engaging. A GP shaft would be the correct one.

Ok, I know that my side casing is a later one as I bought it new last year (a polished one), the shaft I bought from Cambridge Lambretta, they said it was a GP one. So what do I need to be asking for when I phone a supplier? A late model GP shaft?

Thanks [/quote]

In that case it's probably all ok but might be worth checking, I did say it was a long shot

What about a stronger spring?

Have had a few Serveta's in where they had used the same spring(selector) for both selector and piston from the factory. Piston won't be pressed onto gear with enough pressure and hey presto! slippage and wear.

dirtyhandslopez wrote:What about a stronger spring?

Have had a few Serveta's in where they had used the same spring(selector) for both selector and piston from the factory. Piston won't be pressed onto gear with enough pressure and hey presto! slippage and wear.

The first thing that CamLam suggested on the phone this morning - suggested I try a competition spring. About to order one if I can find one as CamLam have ran out!

Next on the to do list is stick a bit of plastecine onto the end of the piston to see if it is connecting to the first gear or not (should be able to judge by the imprint left when I fit it together).

I may have a go at modding the shaft by elongating the gap where the location pin sits so that it pushes the piston out further. I'll see how i get on with a stronger spring first though

I fitted new kickstart mechanism recently and the slot in the arm was tight at the bottom end.

Obviously I just fettled it a wee bit and it was fine.

Sorry for not mentioning earlier but I'd forgotten until you mentioned this.

This could be the problem!





Checked out my last kickstart shaft and the one I have in at the mo and they are both bent! I am hoping that this is the problem, surely they must be straight? Both have a definite bend to them. That would answer why when I swapped the shaft a couple of months ago it worked perfect for a while and maybe the new one bent over time and the problem with chewing up the piston starts all over again???

Anyhoo, I am currently waiting for the postman as I ordered a new Tino Saachi k/s/s from CamLam yesterday. Hopefully this one will be straight and remain so