Clutch slip only in 3rd/4th

[joolz]

Hi Guys

New SIL GP200 with 500 miles to press...

Anyway in 3rd and 4th (when warm) if I put a bit of power on too quickly the clutch slips. Its ok if I build it up gently.

I have adjusted the cable so it's 'slack' (as much as I dare) to no avail.

Because its only on 3rd/4th I am guessing its a cable thing (full twistgrip rotation etc)... but adjustment did nowt

Any ideas or seen this before?

I'm wondering if its worth spending £7 and getting some uprated springs... good idea????

Thanks for any help chaps

Julian

[goldeneye]

could be the kickstart shaft rubbing on the clutch top plate, causing the slip, you can grind it down a tad from inside the cover. just fit some vespa springs around the outside of the original ones, cures most slip in standard or mild tuned engines (and most TS1"s!)

[joolz]

could be the kickstart shaft rubbing on the clutch top plate, causing the slip, you can grind it down a tad from inside the cover. just fit some vespa springs around the outside of the original ones, cures most slip in standard or mild tuned engines (and most TS1"s!)

Thankyou kind sir

I have seen the Vespa tip in Stickies book and it seemed like a damn good idea... Any idea which ones though? I know nowt about Vespas having only ever owned Lambrettas.

Its a shame that the spring stiffness isn't quoted by suppliers then you could have half a chance of working things out.

Cant wait to get tinkering tbh but will wait a few weeks methinks (and you have me pondering on the crank now too ..... curses)

[coaster]

I had the same problem with my tuned 225 engine, Uprated springs cured the clutch slip but mad the lever action unpleasantly heavy, an MB dogleg lever sorted that though

[goldeneye]

joolz, pm your address, and i"ll send you some vespa clutch springs to fit round your lammy ones, i"ve got a canny few spare. they make the lever a bit stiffer, but you get used to it. nylon lined cable will help.

[bsso78]

If its a new engine straight from the crate that hasnt been stripped then the problem is likely to be the clutch plates,the springs are usually ok for a standard engine but the clutch corks arent really cork its more like silly putty and wont grip even if you nail them together.
As Monsieur Goldeneye says the kickstart shaft can rub on the top plate so its worth whipping it out and grinding it back a bit

[joolz]

Brilliant advice chaps .... really great... thanks

Looks like i'm gonna get my hands dirty (for the first time in 20 years )

Having the clutch action a bit stronger is a plus --- A workout combined with ride...

Ohh it also means purchase of Lambretta tools - another plus.... In the old days I used to compress the clutch with a ring spanner attached to the casing ---- I had other 'bodges too' --- only ever had a flywheel removal tool at my disposal. Did the rest with spanners screwdrivers and hammers (for full engine rebuilds)

Mr Goldeneye - Thanks for the kind offer - its greatly apreciated

Julian

[rog60]

If its a new engine straight from the crate that hasnt been stripped then the problem is likely to be the clutch plates,the springs are usually ok for a standard engine but the clutch corks arent really cork its more like silly putty and wont grip even if you nail them together.
As Monsieur Goldeneye says the kickstart shaft can rub on the top plate so its worth whipping it out and grinding it back a bit

When my SIL engine was new had the same problem, changed to surflex 'B'plates and uprated springs. much smoother and still going strong at 4800miles

[joolz]

Ok guys so another question or 5

I can get these Surflex corks for about £15 OR a 5 plate assembly (steels/cork/springs) for £38

So is a 5 plate worth it?

My engine is bog standard but I do have a shiny expansion and carb to nail on over the winter

Not sure if the 5 plate kit has stronger springs...

This stuff as a random search to give you the idea




and




Ta

[tony]

Clutch slip will occur in the higher gears first as you are putting more load on it.. so its a sign it needs sorting.
A simple test is to get up into 4th.. slow rpm and nail the throttle open.. here is where it will start to slip.. just as the motor begins to get on song and starts to create its torque.