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Anything related to Lambrettas... ask tech questions, post helpful info, or just read and learn.
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double h
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Posts: 170
Joined: Sat Nov 15, 2014 12:29 am
Main scooter: SIL GP 200
Location: Dumfries SW Scotland
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Sat Jan 19, 2019 6:44 pm

johnny650 wrote:ok .................sorry my suggestions were of no interest to you . Good luck anyway
They are, was at 22 now at 19. Cheapo electronic ignition kit ,if all else fails I'll fork out for a quality kit.

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double h
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Posts: 170
Joined: Sat Nov 15, 2014 12:29 am
Main scooter: SIL GP 200
Location: Dumfries SW Scotland
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Thu Jan 24, 2019 4:28 pm

This may not be helping.Image

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garry inglis
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Joined: Tue Jul 21, 2015 8:04 pm
ebay user ID: garry52uk
Main scooter: ts1 230 and rb200
Location: darlington
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Thu Jan 24, 2019 7:47 pm

failing head gasket is that plug all the way in

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double h
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Posts: 170
Joined: Sat Nov 15, 2014 12:29 am
Main scooter: SIL GP 200
Location: Dumfries SW Scotland
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Fri Jan 25, 2019 5:13 am

garry inglis wrote:failing head gasket is that plug all the way in
Aye the plugs all the way in, it's in the machine shop now to get sorted.

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double h
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Joined: Sat Nov 15, 2014 12:29 am
Main scooter: SIL GP 200
Location: Dumfries SW Scotland
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Sat Feb 02, 2019 2:17 pm

Fun in the sun. Air leak found.Image

hendy
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Posts: 803
Joined: Mon Jul 07, 2014 10:34 am
Main scooter: lambretta li 125
Location: Tyne and Wear
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Sun Feb 03, 2019 11:26 am

Where?

Adam_Winstone
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Main scooter: Lambretta GP
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Sun Feb 03, 2019 12:16 pm

No, as Holty immediately stated, this will not be the issue with not pulling 4th gear.

If yours has the original li150 4th gear ratio of 5.2:1 then that represents the same 4th gear ratio that the GP200 runs. Q: Is your GP150 top end putting out the same power spread as the GP200..... A: No. As such, your gearing is too long and I'm expecting to hear that it is great in gears 1-3 but then struggles to pull 4th (?).

Adam

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double h
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Posts: 170
Joined: Sat Nov 15, 2014 12:29 am
Main scooter: SIL GP 200
Location: Dumfries SW Scotland
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Sun Feb 03, 2019 12:32 pm

hendy wrote:Where?
Sorted when I took the pic. Was one of the nuts ,New gasket with silicon.

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double h
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Joined: Sat Nov 15, 2014 12:29 am
Main scooter: SIL GP 200
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Sun Feb 03, 2019 12:38 pm

Adam_Winstone wrote:No, as Holty immediately stated, this will not be the issue with not pulling 4th gear.

If yours has the original li150 4th gear ratio of 5.2:1 then that represents the same 4th gear ratio that the GP200 runs. Q: Is your GP150 top end putting out the same power spread as the GP200..... A: No. As such, your gearing is too long and I'm expecting to hear that it is great in gears 1-3 but then struggles to pull 4th (?).

Adam
Aye you are correct. There's a big jump from 3 to 4 but my thoughts were if a Spanish s2 top end could pull it surely a Gp should.?

Adam_Winstone
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Sun Feb 03, 2019 1:42 pm

^... don't worry, that is a VERY common mistake to make. As power from standard motors went up, so did the rev range that they operate at, with the dear ratios being lowered (higher number) to suit:

LI125 = 5.7, GP125 = 6.1

LI150 = 5.2, GP150 = 5.7

TV200 = 4.4, SX200 = 4.8, GP200 = 5.2

... which clearly shows the changes to gear ratios over time. Also note that any other changes that you've made to the engine spec, by way of bigger carb or free flowing pipe (e.g. later SIII or clubman) will have further compounded the issue by pushing power higher up the rev range, making it even less likely to pull 4th.

Good luck getting this sorted.

Adam

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