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clutch problem

Technical help for Series one, two and three Lambrettas. Models include the Li, Li Special, TV, SX, GP, Serveta and API/SIL models

clutch problem

Postby peejay » Sat Feb 24, 2018 1:39 pm

hi guys
currently running (for 3 years) an AF cassette clutch (road version) in my series 2.

motor is RT 225, 30mm carb, AF bigbore

although it's no rocketship it does get off the line pretty quick.

this clutch is good for at least 25bhp (motor was dynoe'd at 16 bhp)

old age is catching up with me and this clutch is just too much for me to use in any sort of traffic.

just for the record i'm running another motor with early moggie 225 in an over the top modmobile (clutch is standard surflex and standard spring layout) and i can guarantee 10,000 trouble free miles before i would change it as a matter of course

so any suggestions as to what should i do?

do you think the standard set up would be ok (maybe change it at 5,000 miles?)

any help appreciated :)

PeeJay
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Re: clutch problem

Postby Adam_Winstone » Sat Feb 24, 2018 1:49 pm

Hi Peejay,

What gears and sprockets in the RT?

If running something like SX200 or LI150 with 15/16/17 front sprocket you could consider fitting a GP200 box and bigger front sprocket, which in turn gives your clutch an easier life and does not need such strong springs.

Adam
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Re: clutch problem

Postby peejay » Sat Feb 24, 2018 2:34 pm

hi Adam

i have SX200 46/15 in the RT motor.

the springs in the AF clutch are the ones that it comes with, i've tried all the different levers with little change, i really need much softer springs to get any benefit.

is there a slightly stronger spring available for the standard clutch?
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Re: clutch problem

Postby Adam_Winstone » Sat Feb 24, 2018 3:36 pm

OK an expensive fix but if you really do end up suffering, do have a read up in the later editions of the Official Home Workshop Manual in the section of transmission components where they go into the range of spring strengths fitted to different models. If you do, you will note that by changing the GP200 sprockets to 18/47 Innocenti managed to fit the weakest springs to their most powerful model. If you follow this through logically, moving to a 19 front should help even further.

You could consider both 4 and 5-plate options for a standard'ish clutch too.

IMO we have all got into the habit of fitting tough springs because the most gearing that uses 15 or 16 front sprockets will need them to cope with a higher BHP motor, whereas we really should be looking more to Innocenti's solution.

Best of luck with it.

Adam

PS - I don't have an answer for the softer AF spring query, sorry.
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Re: clutch problem

Postby ULC Soulagent » Sat Feb 24, 2018 3:49 pm

What about using the bgm super strong clutch springs!! They come in strong/medium/soft versions providing they fit your af setup.im using the medium springs in my 240 Ts1 and it’s reasonably light. The lightest I’ve tried is my mb crownwheel, surflex 4 plater with mb springs on my bgm 195 S2 with yam lever and nylon lined cable. Can pull lever in with my baby finger which surprised the hell out of me.
Shane
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Re: clutch problem

Postby peejay » Sat Feb 24, 2018 5:06 pm

thanks guys for your replies :)

i have fitted the BGM nylon lined cables which helped a little bit and tried the MB yamaha lever but my fingers are too short to gain anything from it :?

think i'm gonna go back to a standard set up but experiment with the springs and will report on my findings :)
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Re: clutch problem

Postby mr mugello » Sat Feb 24, 2018 8:48 pm

I bought an MB dog leg lever. Short length version that they sell now, not sure if these would be any different to the Yamaha version though finger distance wise.. Ruddy dropped the price now since I bought mine, only £9 now ! Fitted cam lam ultimate soft springs, which I would not recommend as still very strong. MB lever was an improvement on being shorter distance to operate.
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Re: clutch problem

Postby rossclark » Sat Feb 24, 2018 10:33 pm

Would the casa side case make a difference looks like it has a ratchet rather than a simple lever for the push rod?
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Re: clutch problem

Postby peejay » Sun Feb 25, 2018 12:28 am

rossclark wrote:Would the casa side case make a difference looks like it has a ratchet rather than a simple lever for the push rod?


the thought did cross my mind Ross, i'm not ruling anything out but i'll go back to basics first and try a couple of sets of springs :)
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Re: clutch problem

Postby Fast n Furious » Sun Feb 25, 2018 3:14 am

Make sure the clutch operating cam that pushes on the thimble isn't worn. If it is, change it for a new one (dead cheap). The shape of this cam is critical to how the clutch feels.
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Re: clutch problem

Postby bike grim » Sun Feb 25, 2018 6:17 am

That really surprises me as I have an AF casttte in 2 scooters (tuned TS1 and Rapido 225) and they are very easy at the lever, as easy if not lighter than the clutch on my standard dl125. I also have a 7 plate LTH in my big motor and that is lighter than them all when combined with a lambro clutch lever and a good thick cable outer.
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Re: clutch problem

Postby peejay » Sun Feb 25, 2018 9:33 am

Fast n Furious wrote:Make sure the clutch operating cam that pushes on the thimble isn't worn. If it is, change it for a new one (dead cheap). The shape of this cam is critical to how the clutch feels.


i've not removed the casing yet but this just might be the problem, thanks for the tip, i've never changed one and would not be looking at that as a possible factor.
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Re: clutch problem

Postby peejay » Sun Feb 25, 2018 9:46 am

bike grim wrote:That really surprises me as I have an AF casttte in 2 scooters (tuned TS1 and Rapido 225) and they are very easy at the lever, as easy if not lighter than the clutch on my standard dl125. I also have a 7 plate LTH in my big motor and that is lighter than them all when combined with a lambro clutch lever and a good thick cable outer.


i've been riding this scoot all through the winter and this problem has gradually got worse, out on it on saturday (30 mile trip) was enough for me, had to change my riding style from boy racer to old git mode just to save a few gear changes!

i have another scoot with same AF clutch (probably only ridden 1,000 miles on it) which hasn't been ridden for ages which i moved in the workshop on saturday afternoon and pulled the clutch in, well what a difference, so much easier to operate

maybe it is wear on that cam, i'll be looking on monday

thanks for all your help guys :)
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Re: clutch problem

Postby Fast n Furious » Sun Feb 25, 2018 3:54 pm

It really can amount to a combination of things and usually and incorrectly the clutch springs themselves get the blame.
Clutch springs only need to be strong enough to do the job of preventing the clutch slipping under maximum load. Any stronger, and its a waste of time and effort.
Like Bikegrim says:- This shouldn't happen with an AF cassette clutch. I have one on my TS1 and can pull it in with only 2 fingers.
Admittedly, it does use a quality, nylon-lined, thick Bowden cable correctly greased and routed throughout. It does have bearings on the pivot point of the lever. The lever is a modified Yammy SR125. There is no slop in the clutch pivot shaft and the cam on the end of this shaft is newish. Attention to detail is the key to a nice clutch!

Hope this helps.
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Re: clutch problem

Postby peejay » Sun Feb 25, 2018 4:27 pm

Fast n Furious wrote:There is no slop in the clutch pivot shaft and the cam on the end of this shaft is newish. Attention to detail is the key to a nice clutch!

Hope this helps.


attention to detail, i'm on the case :)
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Re: clutch problem

Postby peejay » Sun Feb 25, 2018 9:36 pm

cam does centralize

Image



should there be a second washer to take up the excessive slack?

Image



there is a flat spot on the cam

Image



there is a wear groove in the thrust bush


Image



wear on bottom edge of cutout

Image



and wear on the outside

Image



can't see anything wrong with the cassette which slides in smoothly under pressure from a clutch compressor

Image



Image



chain needs adjusting!

Image


i will of course change the cam and thrust bush but to be honest i was hoping they were worn even more

probably about 7,000 miles from new
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Re: clutch problem

Postby holty » Sun Feb 25, 2018 10:56 pm

new cam and brass bush needed , the cam looks too far to one side, there should be a circlip and washer above the cam , on the shaft, that might want a thicker washer to get the cam nearer to the center, as fast and furious said these 2 items can realy improve the clutch action.
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Re: clutch problem

Postby Fast n Furious » Mon Feb 26, 2018 1:01 am

Some old skulduggery might be at work here????
To me..... the wear on that cam aint right for a GP.
Looks like that Cam started out its life in an SX/Li.
You can see the distinguishing wear point where it contacted with the thimble, then after it, the wear, where it contacts with the GP thrust bush.

Anyway Peejay, keep us apprised of the improvements your'e about to make. Valuable lesson for a lot of people to be had here maybe.
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Re: clutch problem

Postby peejay » Mon Feb 26, 2018 7:10 pm

Fast n Furious wrote:Some old skulduggery might be at work here????
To me..... the wear on that cam aint right for a GP.
Looks like that Cam started out its life in an SX/Li.
You can see the distinguishing wear point where it contacted with the thimble, then after it, the wear, where it contacts with the GP thrust bush.

Anyway Peejay, keep us apprised of the improvements your'e about to make. Valuable lesson for a lot of people to be had here maybe.


gonna check my servicing record in the morning, i'm sure the cassette was fitted into brand new indian cases and GP cover when the engine was first built so what you see is how it was supplied to me from new, i like a challenge!
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Re: clutch problem

Postby peejay » Thu Mar 01, 2018 2:58 pm

hi guys
progress has been made

new thrust bush is on the left


Image

new one is .75 mm taller (top of bush is still below the ali casing)

also fitted new cam, there is no room to fit a spacer between the top of the cam and the casing, it prevents the thrust bush from centralizing

fitted the side casing back on and i can now pull the lever in at least 6 times in rapid succession, probably max of 4 before

it's still not as easy as the same set up on the other scoot but much better, as soon as the snow has gone i'll roadtest and let you know :)
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