Hi Members

Went for a ride on Sunday and last set of lights before home I did a big bunny hop and now I have a gear/clutch issue.

The rest of the way home while in gear I had a grounching sound and even if I pull the clutch leaver in I am still in gear.

Adjusted the cable in and out for 30 minutes and could not improve. In neutral all ok.

I put it in gear and it "drags" and makes a noise,like it is not fully engaged or disengaged. If I pull the clutch leaver in while in gear it does not disengage. Cannot push the bike.

Also I put the bike on its side and while in gear I can spin the wheel about a 1/4 turn before I feel resistance. Is this normal? I would assume when in gear I should not have any free turn.

Any assistance/advise would be greatly appreciated.

Thank you,

Mal

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Sorry to bring bad news, but it sounds serious to me. I'd start by getting your hands dirty and having a look at the clutch. It may have experienced a "spontaneous uncontrolled disassembly".

Good luck!

Thanks, we'll look at that!

Hi Marilyn, yes it does sound like the clutch has been damaged rather than a broken cruciform. You say you can spin the wheel 1/4 turn when in gear. There is a bit of play as the gears take up slack but that seems like too much. One hopes that the woodruff key slot on the crank shaft hasn't been torn open. It happened to a scoot of mine.

You can service the clutch without taking the engine out of the frame. You will have to lay it down on the engine side and take off the rear wheel. However to make access much easier, you should remove the carburettor and airbox first. Then take out the lower rear suspension mount bolt. This will allow you to swing the motor further out of the frame. The clutch cover is held in place by 3 bolts. The main danger of this method of clutch removal is that the woodruff key could slip inside the gearbox. If that happens you will have to open up the engine cases. If you pack some clean cloth around the crank shaft, this could lessen the danger. Unfortunately to remove the clutch you do need some specialised tools, one to hold the clutch, a tool to remove the castellated nut and another to compress the clutch plates. 

With a problem like this its always a good idea to check the Cush gear. This is the largest gear within the gearbox and it contains a number of springs within it which cushion the impact of gear selection. With age these can get broken and the thing gets jammed and can't do it job which is one of protecting the transmission from mechanical shock.

Gosh, all this sound so complicated doesn't it? Just take it to one of our sponsors, Roberto - The Vespa Wizard. 0419 365 507. He can pick it up from your home.

Good luck, David

How to dismantle a Vespa clutch.

https://youtu.be/Q2pcHhlxbxs

Thanks David,

Wow that sounds like a challenge!

I'll have a chat to Neb and we'll decide whether to order some tools and get our hands dirty or give Roberto a call :)

Thanks,

M

Hi All Thanks for the assistance thus far

Removed rear wheel, clutch and found,

NO woodruff key. Looks like it was there but no longer as there seems to be a little damage on the clutch pack slot.

Also I have a "stop" point on the main gear and a noise when I rotate by hand. Please see video.

Any help of what the issue is would be greatly appreciated.

here is a YouTube link to the video.

https://youtu.be/XofL4jDMJXw

it ‘IS’ doing weird things! 

A.

As a first port of call 
non disengage - Clutch plates renew - rebuild your clutch
change your woodruff key, clutch cover seal and clutch cable while at it - as a matter of course.

either if it’s a standard motor or tuned pay attention to the clutch plate tabs, burning of scoring to the cork on the plates. it might be just age wear, mal adjustment or low gear oil  - replace, adjust and check - your good to go! 

Look at the clutch bell and retaining circlip check it’s condition - wear or chews replace you whole clutch unit - it’s still a cheap exercise.... GPS or SIP as suppliers will be your friends 

remember not to drop the woodruff key down into the gear space! This can be tricky to remove unless you have the engine out of the frame (you’d turn it upside down to retrieve it! 

the following is more exotic...

B. Check any excess brass file on the inside of the clutch cover

- this May tell you if it’s more than just too much kms use, and clutch grab issue (Thump gear change, springs in primary gone). Brass file would suggest clutch Plunger excessively wear oil thinned with fuel from crank seal over heat. 

your up for a total engine rebuild all seals and Bearings (change the cruciform) 

C. while you have the clutch out and on your bench.

inspect for damage visual the primary cog and retaining plates 

for damage (scoring, rivets pop, or bulging) 

This would indicate also a Bearing seals rebuild Is on the cards (change the cruciform) 

By the way, there are books on the subject 


how to restore CLASSIC LARGE FRAME VESPA SCOOTERS 

Rotary Valve 2-strokes 1959 to 2008 

your illustrated guide to body and mechanical restoration 

by Max Paxton 

..... 

thanks John, we'll take a closer look.

As a ‘book‘ it’s the visual go to 

if you run into problems post them either here 

or https://m.facebook.com/groups/801517836545625?ref=bookmarks

oh your plates for your primary look to be a recent replace going on the non original rivets 

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