Li engine with GP crank.

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onefortheroad
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I'm setting about my first Lammy engine build and despite owning 4 of them over the last 13 years the most I've ever done is change a kickstart shaft. I've decided it's now time to stop being a fanny and have a go!

I have an old completish series 2 engine which I am taking most of the parts from. I am transferring them over to a bare series 3 casing (I am told most parts will swap over?) with the obvious new gaskets, seals, bearings etc and anything else it needs.

I thought I'd take the opportunity to fit a gp crank. My question is what would I need to change if fitting a gp crank to an LI casing? Are the bearings different?

Thanks

Dan
Tractorman
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The flywheel side bearing is bigger and so you leave out the ring that sits between the seal and the bearing. Don't forget the flywheel.
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coaster
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Tractorman wrote:..................... Don't forget the flywheel.
Were you planning on going electronic too? either way, as Tractorman says, you will nee a new flywheel to match the bigger, stronger taper on the GP crank.
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HxPaul
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Make sure its not a SIL gp crank with Indian bearings...........could last 2 weeks,2 months,2 years,but sooner or later(usually sooner) it will go "bang".
Scooterdude
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I quite like the mec cranks, Harry Barlow checked mine and found it to be spot on. Glasgow Lambretta are selling them for around a hundred quid.
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onefortheroad
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Cheers lads.

Yes I'm thinking electronic kit so it would basically be

GP crank
GP flywheel bearing
GP type electronic kit
Everything else the same?

I've read here http://www.scooterhelp.com/tips/engine/ ... .seal.html and in stickys that you have to take the inner part of the flywheel bearing off the crank taper and match the new one? Is this necessary and would a new crank such as the MeC one come without one on?

Thanks again
Tractorman
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New cranks don't come with that part of the bearing.
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HxPaul
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onefortheroad wrote:Cheers lads.

Yes I'm thinking electronic kit so it would basically be

GP crank
GP flywheel bearing
GP type electronic kit
Everything else the same?

I've read here http://www.scooterhelp.com/tips/engine/ ... .seal.html and in stickys that you have to take the inner part of the flywheel bearing off the crank taper and match the new one? Is this necessary and would a new crank such as the MeC one come without one on?

Thanks again
You will have to get a new flywheel bearing because you're changing from standard taper to GP taper.The inner bearing race has to be pushed onto the new flywheel.Dont use a naked flame to heat up the inner race,as in the scooterhelp instuctions because the heat will alter the molecular structure of the race and it may spin eventually on the crank causing the bearing to fail.
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coaster
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HxPaul wrote:..................The inner bearing race has to be pushed onto the new flywheel
I think you meant 'crank' ;)

The trick is to put the crank in the freezer overnight and warm the bearing tract with a hot air gun and it should just drop onto the crank with no more than a light tap. Warming the mag housing in the oven and freezing the outer bearing race with installing the outer races but too hot will melt the oil seals.
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HxPaul
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Yes,sorry about that :?
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