Gear jumping ....weak selector spring ??

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225worb
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Ive just stripped a servetta 150 gear box due to it jumping out of gear under load. New sliding dog, spring and ball bearings purchased ready to fit thinking the sliding dog would be worn ...
With closer inspection the sliding dog looks absolutely fine with plenty of life left slight edge wear but ok...there is resistance still when moving the selector through all gears but how much should there be ??
inner gear services are undamaged too..(and fitted correctly )
Could the selector spring lost tension ?? Ive a replacement as mentioned so inclined to go ahead and hopefully resolve the problem..
Thanks in advance Nik
alanscottj
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A new spring sorted my jumping gear :D
Lambretta Series 2 Rat - RB260, SuperTourer, Cyclone 5 gearbox 😎👍
hendy
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Cables too tight? Obvious but we all make mistakes.
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GTFOMWSC
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Its the spring alright had it with mine replaced it and its not jumped since.It was ok until you got to about 45 then kept jumping out of 4th, thrash it in 3rd it would jump as well.Easy check is the length compare it to a good new one and it will be about 2mm shorter.
the man don't give a f@@k
Muppet
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Main scooter: SX 150 running in

225worb wrote:Ive just stripped a servetta 150 gear box due to it jumping out of gear under load. New sliding dog, spring and ball bearings purchased ready to fit thinking the sliding dog would be worn ...
With closer inspection the sliding dog looks absolutely fine with plenty of life left slight edge wear but ok...there is resistance still when moving the selector through all gears but how much should there be ??
inner gear services are undamaged too..(and fitted correctly )
Could the selector spring lost tension ?? Ive a replacement as mentioned so inclined to go ahead and hopefully resolve the problem..
Thanks in advance Nik
ya can use a kickstart piston spring instead
C’est la vie
225worb
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Posts: 137
Joined: Tue Apr 28, 2009 6:09 pm
Main scooter: Vespa 225, Falc , 230 S2
Contact:

Right .....sliding dog out and slight wear on the lugs ...ive replaced it anyway
The selector spring was 5 mm shorter than the new replacement .....so thats now been replaced...
Thanks for the advice ...updates soon !!!
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