Scooterotica

having a bit of a binge toniht regarding posts so i apoligise! but anyone know know why my scoot would rattle in neutral but when warm but when i pull in the clutch i have no rattle ! i am no mechanic and am a novice with lambretta engines! but when when cold i dont get the rattlein neutral and gear changes are sharp and crip! when the engine is warm i get the rattle only in neutral but if i pull the clutch lever in it goes! also when engine is warm sometimes particularly at high revs sometimes i feels like its clunking into gear! like the clutch doesnt fully engage! im wondering if its something todo with thickness of plates and them expanding when they get warm menaing that the clutch doesnt work properly! if anyone has any thoughts orcan explain in laymans terms howclutch works etc it ouwl be appreciated
thanks in advance

Re first item:- the rattle you can hear is the gear box end plate shim which has worn to where it SHOULD be checked for excessive wear and replaced, but in practical terms this is not always necessary or practical for reasons of getting someone to do it (labour costs). If you listen to other Lambretta engines you will probably realise that they others do it as well, mine does. I check the end plate shim clearance ONLY when the transmission cover is off and if the gap is really excessive (not often)I replace the shim by calculating the excess play difference plus the thickness of fitted shim and fit a thicker shim.

Not really sure about your clutch problem, you may be right about the temperatures but also check the oil level in the gearbox. Any Lambretta workshop manual will give instructions on the procedure. If you have a (Slimstyle Series 3) lambretta then 'Sticky's' book is highly recommended. You'll learn a lot very quickly

You're problem sounds like the kick start plunger is deployed a little too much when the kick-start is up. The two teeth on the kick-start plunger are rattling on the first gear's teeth. When you pull the clutch in, the gear box stops turning and the noise stops.

thanks for your replys, Hen you say the endplate shim do you mean the gearbox shim? last august i went to change the clutch plates and investigate the rattle and found i had excessive gap between the gearbox shim and end plate, but found the cause was a rear hub bearing had gone. changed that for an MB one. was told i would probably need a smaller shim (about 1.2 i think) than what was originally in it (a 1.5) but still needed a 1.5 shim. anyway! the engine was reassembled by someone who knows what they are doing who was on the island for august bank holiday (which i was extremely greatful for there help) as when i put it back together i couldnt enegage gear properly as the crown wheel sat to high so wouldnt spin freely! why i don't know can only think its because replacing all the new bearings gearbox end through everything out slightly! as i said the bike runs well apart from this rattle! ive checked the back wheel and no play what so ever! so im enclined to go with knowledges suggestion, but how do you solve it knowledge? is it just a matter of replacing the plunger or do i need to try something else? the kickstart is on the splines that gives very little kick anyway and if i remove the kaick start the shaft does not move any further round if than when the kickstart is on if that makes sense

so im enclined to go with knowledges suggestion, but how do you solve it knowledge? is it just a matter of replacing the plunger or do i need to try something else? the kickstart is on the splines that gives very little kick anyway and if i remove the kaick start the shaft does not move any further round if than when the kickstart is on if that makes sense

Do you have the end-plate with the built-in ramp, or is the ramp bolted into the inside of the side casing? If it is the latter, you can adjust the point at which the plunger is deployed. I suspect this is the problem (deployment) rather than the components. I think Sean did a recent article on this conversion from end-plate ramp to bolt-in ramp. Search the forum.

Once correctly adjusted, there should be as much "kick" as before, if not better.

Knowledge wrote:I think Sean did a recent article on this conversion from end-plate ramp to bolt-in ramp.

It was one of Jason's superb 'how to' guides: http://scooterotica.org/forum/viewtopic.php?f=5&t=2286

Quick tip.
When I'm putting a trans. together, I usally check shim clearance withouth the dowels or christmas tree fitted. Make taking it apart and puting it back together again a whloe lot quicker and easier.

thanks for replys yes it is the GP type with the ramp on the end plate, i have seen the article your on about so think i will have to wait till next time the engine is apart and make get the modification done
thanks again

Try taking the rubber kickstart bump stop out until then. It'll let the kickstart go up a hair and may solve the prob.

cheers for that dirtyhandslopex. been thinking about this and dont think it will make a difference due to the fact that i have pulled the kisckstart off the splines the other weekend and it did not return up pass the bump stop! any other suggestions