Spanish Lady

[dickie]

The recommendation for a GP crank seems reasonable, though I've never witnessed a failed Li taper crank.

Really?

That looks to me like corrosion cracking. That's when corrosion causes a minute crack which propagates over an extended period. IF that were the main cause of li style cranks failing, then it would go a long way to explain why they didn't fail on 70s race engines; they simply hadn't had enough time to deteriorate by then.

[carlos fandango]

Dose the flywheel look like a std type ? Or have five triangle holes ? The triangle one is the electronic type , the std looking one is points.
Both types have ac or dc variants
Both have red coils ...although differnt types
The five pin reg. if for dc output.......but , you may have an ac stator ?
Ive got an ac and a dc type electronic stator , and from memory the ac has 3 wire and the dc has 4 , ill check when i get to work

[Rob64232]

Hi,

In 1981 I gave Dave Webster my brand new Jet 200, the complete scooter, with 300 miles on the clock for him to build me a Yamaha DT pistoned 200.

He said I needed a GP crank or i'd snap the smaller tapered one of the Jet. I said 'it's brand new it will be fine' [spotty 18 year old questions a top Lammie racer????? the joys of youth].
As I was leaving he just said '1500', I asked what he meant and he said 'miles before it went 'bang'. Ha Ha! he was wrong....it was only 1200.
If you ever met him you'd know what a sarky bugger he could be, he wasn't surprised to see me back.

It wasn't just a one off, another local lad had the same conversion on a new Jet with the same result, only his occurred quicker than mine. Two new scooters so no fatigue issues.
It may just have been Dave's conversions, anyone who ever had one will know what I mean.

Rob

[coaster]

Back in 1971 a mate bought a brand new SX200 that had been stood unsold in a Felixstowe dealers shop for a few years. He fitted a Royspeed 225 Barrel, Royspeed 50mm Big Bore exhaust and a 30mm VBA Delorto more or less as soon as he got it and he snapped the crank within the first 60 months or so whilst thrashing down the A12 2 up. That was the only snapped one I recall but then that was a very quick SX and it was ridden very hard.

[Adam_Winstone]

Even the official Home Workshop Manual acknowledges this as being an issue so I don't think that anyone should be in any doubt of it being a fairly regular happening. Indeed, it must take quite a high number of failures for a supplier to put such a failure into text.

Adam

[carlos fandango]

Li taper shearing is something im interested in .
So not wanting Scooterlam to blow a fuse ( pun intended lol ) ill start another thread

[Scooterlam]

Li taper shearing is something im interested in .
So not wanting Scooterlam to blow a fuse ( pun intended lol ) ill start another thread

You didnt tell me they had fuses.