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Has anyone had a rear wheel lock up when shifting gears?

Was going 15-20mph and shifted into 2nd about to turn a corner and had a lock up at the rear which resulted with me and the Vespa on the floor...

Happened so fast, but I tried to hit the rear brake and of course nothing happened and the next thing I know, I'm skidding down the road... on the side, bunch of road rash, but at least safe...

Thought it might have been oil on the brakes or on the floor, but would've just coasted through it...

Vespa started up straight away... and managed to make it back home

Wondering if it's there's a problem with the gears and cruciform?
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Ouch - Are you OK? Sucks going down. I don't have any ideas, just wanted to check on you....
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qascooter wrote:
Ouch - Are you OK? Sucks going down. I don't have any ideas, just wanted to check on you....
All good, I think could've been worse... nothing broken sore though from going down...

Vespa has a Bunch of cosmetic scratches on the legshield, side panels, the mudguard has some (wanted to change it anyways..) but mechanically it seems ok so far...

Thanks for asking, appreciate it! Still typing messages... lol

I'm thinking maybe it's the gear selector? Ive had a few times where I'm bombing along, I have the clutch pulled in, I'm about to change gear, I hit a small bump in the road, and I hear a clunking sound like it's changed gears but of course on the handlebars I've done nothing... then I shift into the gear I want (usually 2nd to 3rd...)
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Damn 108, sorry to hear.

Sounds like maybe a clutch issue ... maybe selector, possibly gears need shimming. Were you downshifting from 3rd or upshifting from 1st? Did you maybe miss the shift and end up in first instead of second?

I'd start by getting the rear wheel up in the air. Shift up and down through the gears and see if you can re-create it.

Btw, transmission lockups are the worst. There's nothing you can do. Clutch is useless. Going around a turn was the worst possible time. Glad your ok.
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SoCalGuy wrote:
Damn 108, sorry to hear.

Sounds like maybe a clutch issue ... maybe selector, possibly gears need shimming. Were you downshifting from 3rd or upshifting from 1st? Did you maybe miss the shift and end up in first instead of second?

I'd start by getting the rear wheel up in the air. Shift up and down through the gears and see if you can re-create it.

Btw, transmission lockups are the worst. There's nothing you can do. Clutch is useless. Going around a turn was the worst possible time. Glad your ok.
Yeah, felt pretty helpless... trying to remember if I tried pulling the clutch back in after the lock up... might not have done that, because I have just released it... my gut says I did, because I'm pretty good with clutch actions... but can't remember...

It was shifting from 1st to 2nd, then I usually turn the corner then pull the clutch back in as there's a traffic light right after the corner to prepare to stop... I didn't even make it to the turn but was leaning in to prepare for it... this is all downhill...

I have a feeling I won't be able to recreate it with the wheel off the floor because it's downhill, the Vespa seems pretty solid when I have it level... Revving the engine to 8000rpm and it didn't jump into gear...

But will give it a try and see if anything comes of it...

It might be the clutch... I know my pressure plate is pretty worn from the actuation arm and bushing rubbing against it... 6 years and not changed it... but I'm not sure if it has anything to do with the lock up...
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Possibly something in the gear box broke free and got stuck in the gear? Ie the plastic oil guide or something else? Only suggestion i got.

Glad you are ok!
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Something in there
I had a clutch basket Crack. I replcaced the clutch but didn't notice the anything missing. Somehow a small piece got loose and found it's way in between the gears. Insta-thunk-stop. Fortunately I was not moving (at a stop light). Wheel locked solid. Unaffected by pulling the clutch. Roll bike backwards, small clunk. started right up. Rode home at 2mph. Found the piece now gently tucked in between two gears but not mashed in the teeth.

Sounds like based on your experience, I got pretty lucky. I hope you didn't get too banged up.
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Not our week is it. Pretty unlucky. Hopefully nothing banged up beyond repair.

I wouldn't ride again until you know what it was. probably don't feel like it anyway.
Could easy be the gear selector. They have a few ways of missing gear. With it off, hold the gear arm and see how much play there is before the handlebar moves.
Other is the cruciform coming loose. Slider should be tight.
Spin the wheel in neutral to check if it's bent. And no clicking.
Worst case something metal loose in the gearbox. Magnetic plug will find that.
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Yikes, my sympathies and my worst nightmare. I had something similar... going about 32 mph on a straight away and was shifting from 3rd to 4th. Back tire completely locked but I was able to stay upright... scared the ^&%# out of me but all safe. I couldn't figure out what caused it as the scooter was fine afterwards, got me home. I was thinking that I missed the gear, releasing the clutch too early. I would double check the gearbox for a foreign object.
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swiss1939 wrote:
Possibly something in the gear box broke free and got stuck in the gear? Ie the plastic oil guide or something else? Only suggestion i got.

Glad you are ok!
Yeah pretty sore now after the adrenaline has gone... lol

Could totally be a possibility that something got stuck, because it was pretty sudden after the clutch release... looks like a fish around the gearbox and clutch will be needed...
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67GT125 wrote:
I had a clutch basket Crack. I replcaced the clutch but didn't notice the anything missing. Somehow a small piece got loose and found it's way in between the gears. Insta-thunk-stop. Fortunately I was not moving (at a stop light). Wheel locked solid. Unaffected by pulling the clutch. Roll bike backwards, small clunk. started right up. Rode home at 2mph. Found the piece now gently tucked in between two gears but not mashed in the teeth.

Sounds like based on your experience, I got pretty lucky. I hope you didn't get too banged up.
Hope it's not the clutch basket! The MMW served me pretty well so far, I bashed the crap out of it and it's bullet proof...

But joking aside, total get your point, I have a suspicion it might be a loose gear tooth will have to have a look...
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Jack221 wrote:
Not our week is it. Pretty unlucky. Hopefully nothing banged up beyond repair.

I wouldn't ride again until you know what it was. probably don't feel like it anyway.
Could easy be the gear selector. They have a few ways of missing gear. With it off, hold the gear arm and see how much play there is before the handlebar moves.
Other is the cruciform coming loose. Slider should be tight.
Spin the wheel in neutral to check if it's bent. And no clicking.
Worst case something metal loose in the gearbox. Magnetic plug will find that.
Definitely not our week mate...

Feeling even more sore as the day goes on.

With the gear selector, is the play with the dog teeth? Even with the correct selector cable tension it could still pop out right?

Had some clicking when I parked the bike in neutral... light noise... I thought it was just the axel spinning noise... wasn't loud, like a child tapping something not even that loud... it's more like a sticker stuck to the tire noise...
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chilidog wrote:
Yikes, my sympathies and my worst nightmare. I had something similar... going about 32 mph on a straight away and was shifting from 3rd to 4th. Back tire completely locked but I was able to stay upright... scared the ^&%# out of me but all safe. I couldn't figure out what caused it as the scooter was fine afterwards, got me home. I was thinking that I missed the gear, releasing the clutch too early. I would double check the gearbox for a foreign object.
Sounds about the same...!

I did think might it have been a seize? Had a soft seize before... But I wasn't going fast and the clutch would've responded if it was seized.

So still not figured out what happened?
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Sorry to hear about your spill, 108. Glad to hear you're mostly ok. Take it easy and heal up quick, and fully. In the man time, I'd say could be something broken/locked up/soft seize/frozen bearing/gremiln/whatchamacallit... only one way to know for sure... crack that sucka open and get at it! Good luck!
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108 wrote:
Jack221 wrote:
Not our week is it. Pretty unlucky. Hopefully nothing banged up beyond repair.

I wouldn't ride again until you know what it was. probably don't feel like it anyway.
Could easy be the gear selector. They have a few ways of missing gear. With it off, hold the gear arm and see how much play there is before the handlebar moves.
Other is the cruciform coming loose. Slider should be tight.
Spin the wheel in neutral to check if it's bent. And no clicking.
Worst case something metal loose in the gearbox. Magnetic plug will find that.
Definitely not our week mate...

Feeling even more sore as the day goes on.

With the gear selector, is the play with the dog teeth? Even with the correct selector cable tension it could still pop out right?

Had some clicking when I parked the bike in neutral... light noise... I thought it was just the axel spinning noise... wasn't loud, like a child tapping something not even that loud... it's more like a sticker stuck to the tire noise...
That faint clicking noise sounds just like it. If the cruciform gets bent it can catch 2nd and 3rd at the same time. Take the selector off and check it all over.
The cables won't stop the gears jumping, however tight they are.
If you can hold the cruciform between 2nd and 3rd and spin, then it's not bent.
Usual issues for the clicking are, the slider has come unscrewed. The gear selector pawl has heavily worn it's pivot. Selector arm is wobbly on its pin. Incorrect quantity of gaskets to adjust into neutral. And if it's none of these the selector box is from a different model.
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Jack221 wrote:
That faint clicking noise sounds just like it. If the cruciform gets bent it can catch 2nd and 3rd at the same time. Take the selector off and check it all over.
The cables won't stop the gears jumping, however tight they are.
If you can hold the cruciform between 2nd and 3rd and spin, then it's not bent.
Usual issues for the clicking are, the slider has come unscrewed. The gear selector pawl has heavily worn it's pivot. Selector arm is wobbly on its pin. Incorrect quantity of gaskets to adjust into neutral. And if it's none of these the selector box is from a different model.
So had a look at spinning the wheel in neutral. if you can hear the faint scrapping noise thats what i heard last time... Cant find where the noise is coming from, thought it might be the brakes, but pressing on the brakes makes no difference.

https://youtu.be/GMCnhzWA67c

Heres me going through 1st to 4th:

https://youtu.be/THZ8tftnJ0o

I managed to feel a spot between 2nd and 3rd where it doesnt engage the drive shaft (not in the video)... its like a fake neutral... could that be a problem? happened too with the handlebar and not just with the slider rod.

Gear selector seems to be solid at the paw and with the arm, no huge freeplay but the pivot that engages the slider is pretty loose... or is it suppose to be like that?

https://youtu.be/_XH6r32rzPU

Not a lot of play on the sliding rod, doesnt seem to be bent, and the driveshaft doesnt seem bent either:

https://www.youtube.com/watch?v=9QHudUPp3RU

ordered some new clutch parts... will pull the clutch off and have a look... might end up splitting the cases as well anyways and have a look to see if theres any bits in floating around...
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Think I see the pawl pivot moving. If you take out the spring it's easier to see. Replacement is in the refurb kit.

Cruciform still on tight?

Clicking is the cruciform not sitting in neutral.

Magnetic sump plug will pick up anything in there.
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Jack221 wrote:
Think I see the pawl pivot moving. If you take out the spring it's easier to see. Replacement is in the refurb kit.

Cruciform still on tight?

Clicking is the cruciform not sitting in neutral.

Magnetic sump plug will pick up anything in there.
Forgot to mention the cruciform is tight... tried re-tightening, it didn't move (I understand it's reversed threads)

Wondering if the shimming is wrong... the driveshaft is from another engine, but I didn't reshim or check alignment, was assuming it was the same considering they're the from the same type of lusso engine.

Paw pivot? The areas circled in green? Had some play, some slight play, but nothing significant... seems acceptable

Also attached a picture of the plug... the shavings are less than 20kms but nothing bigger came from it...

Oh and the oil in the videos (if you can spot it... is the same as the plug, less than 20kms and new 10w40 jaso ma oil

Just extra info
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Oh, thinking it's not a seize because I remember picking the Vespa back up and the engine was still running in gear, the back wheel was still spinning with the engine running...

Also some extra info for sleuths ...
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is it possible you shifted from 2nd to 1st thinking you were shifting 1st to 2nd? I've done that scared the crap out of me.
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hibbert wrote:
is it possible you shifted from 2nd to 1st thinking you were shifting 1st to 2nd? I've done that scared the crap out of me.
I'm pretty good with engine braking and feeling clutch action before it's happened... so doubt it... it was a proper skidding lock up, rather than "oh shit, extra revs..." lol...
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108 wrote:
Paw pivot? The areas circled in green? Had some play, some slight play, but nothing significant... seems acceptable
The pivot with the slot in the top. Is possible to get the spring out with pliers, then you can really see how much play there is. They always wear here. The video seems like yours is too loose.
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Jack221 wrote:
108 wrote:
Paw pivot? The areas circled in green? Had some play, some slight play, but nothing significant... seems acceptable
The pivot with the slot in the top. Is possible to get the spring out with pliers, then you can really see how much play there is. They always wear here. The video seems like yours is too loose.
Double checked the paw and arm... seems pretty solid... no huge play. first 3 secs of the video I'm using a decent amount of force... no wriggle

https://youtu.be/pQzM5hxT7zg

Im thinking of clutch off next and see if a magnetic rod can fish anything out of the crankcase but might wait for the clutch pressure plate to arrive first...
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108 - first up - sorry man - that is brutal.
Glad its just some bruises and skin that will heel - without breaks.
Doesn't mean it doesn't suck.

Can you recap the incident and what happened afterwards as specifically as possible?
- You shifted in to second - and when you let out the clutch it locked up.
- But when you went to pick up the scoot - the rear wheel was spinning and the motor was running.

All - Sime66 did a spread sheet break down on what turns and when between gear box and crank shaft that could be helpful here. I looked but couldn't find. Anyone know where that is?

108 - If it locked up when you shifted - that would have stopped the motor - momentarily anyway - I think. The fact that it was running and spinning when you realized you were on the ground sounds like something jammed - and then released - to me.

As painful as it is - I would be hard pressed not to split the cases personally - and have a very close look - for both foreign objects - as well as any cracked rods, seats, or gear teeth.

I think Sime's chart could be helpful in coming up with a theory that would fit the bill from your symptoms.

Sorry again - and glad you are bruised but not broken.
Take it easy - fall like that takes some time.
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charlieman22 wrote:
108 - first up - sorry man - that is brutal.
Glad its just some bruises and skin that will heel - without breaks.
Doesn't mean it doesn't suck.

Can you recap the incident and what happened afterwards as specifically as possible?
- You shifted in to second - and when you let out the clutch it locked up.
- But when you went to pick up the scoot - the rear wheel was spinning and the motor was running.

All - Sime66 did a spread sheet break down on what turns and when between gear box and crank shaft that could be helpful here. I looked but couldn't find. Anyone know where that is?

108 - If it locked up when you shifted - that would have stopped the motor - momentarily anyway - I think. The fact that it was running and spinning when you realized you were on the ground sounds like something jammed - and then released - to me.

As painful as it is - I would be hard pressed not to split the cases personally - and have a very close look - for both foreign objects - as well as any cracked rods, seats, or gear teeth.

I think Sime's chart could be helpful in coming up with a theory that would fit the bill from your symptoms.

Sorry again - and glad you are bruised but not broken.
Take it easy - fall like that takes some time.
Thanks CM2, still feeling super sore even after 36hours... lol the bruises... surprised to see the road rash has no stones... not the most pleasant picking stones out of your skin... lol

Yeah, so the more i think about it, the more i remember.

So just riding over to the spot i usually do the carb runs. theres a loop of about 1km i do before i get there, its a good warm up test, as anything happens, i can push it home. So this road i had the wipe out on, I've ridden down 1000 times or more, its the road i ride to work on. The road turns right, goes down hill for about 100metres, then takes another right, before hitting a set of traffic lights.

So at the first right, im in 1st gear as its an uphill slope before going downhill, I take the turn, its all good, then the road starts downhill, i shift to second, give a twitch of gas which makes it quite fast, im about 50metres on that downhill and I release the clutch and it locks up... then its a little hazy, but i THINK i pull the clutch, nothing happens, i definitely hit the front break to try slow down, hit the rear break which did nothing but push the vespa to lean to the left, and wobble wobble and the vespa is on its left side sliding down the slope with me just to the left of the vespa. My immediate reaction was "What the hell happened to the clutch?"

Dusted myself off, bike is leaning on the clutch side of the handlebar, I step over it to pick the bike up and to my surprise, I notice the engine is still running, I usually look to see if its still running and if theres fuel pouring out, and notice too the rear wheel is still moving (not momentum it was spinning pretty evenly)... pick the bike up and it stalls. I vividly remember it stalling when the rear wheel touched the floor (but actually shouldnt it have stalled if its in gear because theres no throttle??)

push the bike to one side, talk to a bunch of people and kick started it to see if it would run and it started first kick, got a little adventurous and started riding down the road, then it occurred to me i should probably push it... stopped did a visual inspection, clutch still works etc, then i realised im a little far out kicked it again and slowly rode it back home... went through all the gears fine... had the leg shield rubber flapping about but all seemed fine.

So did the videos yesterday after family commitments, it was driving me crazy to not know what it could be... but seems all to be fine...

I feel like it might be a primary tooth broke off... ive had that before... but the previous time, i was pushing it hard 1st to 2nd gear, and i heard it break that time... you could hear the tooth rattle around too...

Looks like i'll be splitting the cases... kinda dont want to do it, especially after spending the time doing the leakdown test etc and i spent a lot of time to make sure the gasket was on the small side of the crankcase properly to avoid oil suckers, and its one of those fancy BGM gaskets too (im not buying anything from Scooter center for a while)...... also just rethinking the need to rewire the ignition (it was a splice job that i never ended up adding connector properly... urghh... but looks like we might be splitting cases together... lol!

To be honest, the driveshaft, gears and primary are all taken from another engine, old, but i never used before... stock parts... the reinforced set was stuck in another rotary engine setup... lesson learnt, but honestly i wouldnt have done it any other way.... I'll probably gut that engine and transfer everything over...

Interested to see the chart. Not quite sure if its applicable, but good to have new insights.
⚠️ Last edited by 108 on UTC; edited 1 time
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Oh man - that's tough - and so easy to second guess.

The part I am struggling with:
- cause of event seems to have transpired when clutch was released.
- That means wheel was engaged with motor, motor was running, but wheel was locked.
- Only scenario that comes to mind: it was somehow still in 1st gear.

Did you coast a little/pick up speed before letting clutch out?
I guess I would go have a close look at cruciform & or play at shift box as you have done.
I've certainly caught first when I thought I was in second more than once - but never on a down hill...
Maybe combo of catching first - for what ever reason - plus brake - and scoot got out from under you super quick.

Best I can offer - not much ik - my trick for cleaning cases that makes it a breeze.
These YELLOW roloc devices in an air grinder or drill take off gasket but don't harm the aluminum surface. I hate gasket scraping...

https://www.amazon.com/3M-07527-Roloc-Bristle-Grade-Yellow/dp/B000FW2M2C
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charlieman22 wrote:
Oh man - that's tough - and so easy to second guess.

The part I am struggling with:
- cause of event seems to have transpired when clutch was released.
- That means wheel was engaged with motor, motor was running, but wheel was locked.
- Only scenario that comes to mind: it was somehow still in 1st gear.

Did you coast a little/pick up speed before letting clutch out?
I guess I would go have a close look at cruciform & or play at shift box as you have done.
I've certainly caught first when I thought I was in second more than once - but never on a down hill...
Maybe combo of catching first - for what ever reason - plus brake - and scoot got out from under you super quick.

Best I can offer - not much ik - my trick for cleaning cases that makes it a breeze.
These YELLOW roloc devices in an air grinder or drill take off gasket but don't harm the aluminum surface. I hate gasket scraping...

https://www.amazon.com/3M-07527-Roloc-Bristle-Grade-Yellow/dp/B000FW2M2C
Thats the thing, something i cant answer too, is "was it the clutch release that started it, or it was just by chance that it happened when i released the clutch..." I'm leaning more towards it was the clutch release that started it...

Yup, so 1st gear, added some a little throttle, 2nd gear, add throttle, released... lock up... So maybe it popped back into 1st? not ruling it out...

Never had gears pop in and out... had a friends PX which wouldnt go into 2nd easily and would go striaght from 3rd to 1st...

its just gut feeling that it got jammed too... also the cruciform might be pretty worn now... its gotten a proper hammering from the carb tests, honestly hope i find something in the cases...

I'm the opposite, love scrapping gaskets... its like therapy... lol

What i hate is using new gaskets... feel its such a waste...

Oh wanted to ask what you use to take photos of inside the cylinder? a probe with a light?
UTC

Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: UTC
Posts: 4437
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
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Location: London UK
UTC quote
108 wrote:
Jack221 wrote:
108 wrote:
Paw pivot? The areas circled in green? Had some play, some slight play, but nothing significant... seems acceptable
The pivot with the slot in the top. Is possible to get the spring out with pliers, then you can really see how much play there is. They always wear here. The video seems like yours is too loose.
Double checked the paw and arm... seems pretty solid... no huge play. first 3 secs of the video I'm using a decent amount of force... no wriggle

Im thinking of clutch off next and see if a magnetic rod can fish anything out of the crankcase but might wait for the clutch pressure plate to arrive first...
Thats not it. It's not the main arm it's the small one on top. Checked the video again. There is play in it. I can see it. Is much easier to see with the spring out. Get yourself a gear selector refurb kit.
https://www.sip-scootershop.com/en/product/selector-arm-selector-box-top_12135800

With the thick gaskets on good casings, I don't use sealer anymore. So much easier.
OP
@108 avatar
UTC

Ossessionato
PX 200
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Ossessionato
@108 avatar
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UTC quote
Jack221 wrote:
108 wrote:
Jack221 wrote:
108 wrote:
Paw pivot? The areas circled in green? Had some play, some slight play, but nothing significant... seems acceptable
The pivot with the slot in the top. Is possible to get the spring out with pliers, then you can really see how much play there is. They always wear here. The video seems like yours is too loose.
Double checked the paw and arm... seems pretty solid... no huge play. first 3 secs of the video I'm using a decent amount of force... no wriggle

Im thinking of clutch off next and see if a magnetic rod can fish anything out of the crankcase but might wait for the clutch pressure plate to arrive first...
Thats not it. It's not the main arm it's the small one on top. Checked the video again. There is play in it. I can see it. Is much easier to see with the spring out. Get yourself a gear selector refurb kit.
https://www.sip-scootershop.com/en/product/selector-arm-selector-box-top_12135800

With the thick gaskets on good casings, I don't use sealer anymore. So much easier.
Ah I think I know what you mean...!

The small arm holding the paw teeth

Does the small arm play affect the switching that much? I thought the spring and teeth were the important parts of the operation.

Will have another check and see...
Forum member supplied image with no explanatory text
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UTC

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UTC quote
Glad you are OK!

Watching with interest to see if splitting the cases solves the mystery.
OP
@108 avatar
UTC

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@108 avatar
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UTC quote
Went to double check the small selector arm play, it has some, but it's no more than 0.5mm (if that)

Here's a video of my thumb pushing the arm towards the right side of the engine...

https://youtu.be/gchPzOIYDbQ

How do you service the small arm? Seems straightforward but I couldn't unscrew the small screw on a spare gear selector that I had lying around

But went to try something, which was to put it in gear and pulled the clutch without the engine running and roll the bike along... (tried 1st and 2nd, then rolled it more and put it into 3rd and 4th)

Seems like there's a lot of drag as soon as I engage gear, even with the clutch lever pulled in. The drag seems to disappear after rolling the bike a bit... reappears after I release the clutch lever and pull back in... seems like it might be super sticky clutch plates or the clutch isn't disengaging properly...

Drag feels a lot like the beginning of my lock up...
⚠️ Last edited by 108 on UTC; edited 3 times
OP
@108 avatar
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UTC quote
Birdsnest wrote:
Glad you are OK!

Watching with interest to see if splitting the cases solves the mystery.
Thanks man... not sure I'll find anything... but will be doing some upgrades when I do split it..
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UTC

bodgemaster
63 GL, 76 Super (x2), 74 Primavera (x2), 79 P200, 06 Fly 150
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bodgemaster
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UTC quote
Start with the clutch ...
@mjrally avatar
UTC

Veni, Vidi, Posti
73 & 74 Rally, 76 ET3, 80 P200, 06 PX150, 61 Ser 2, 65 Silver Special, 90 V5N 50, 01 ET2, 2015 HD Road Glide Special
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@mjrally avatar
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UTC quote
Yep. Check the clutch. See if it blew/ loosened up on the crank.
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UTC quote
Quote:
How do you service the small arm? Seems straightforward but I couldn't unscrew the small screw on a spare gear selector that I had lying around
Have experienced the same thing. No chance the small arm screw will come on done. (Used all my tricks)

Does anyone have some specific experience with success in unscrewing that little screw?
UTC

Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: UTC
Posts: 4437
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Jet Eye Master
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Joined: UTC
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Location: London UK
UTC quote
108 wrote:
Went to double check the small selector arm play, it has some, but it's no more than 0.5mm (if that)

Here's a video of my thumb pushing the arm towards the right side of the engine...

How do you service the small arm? Seems straightforward but I couldn't unscrew the small screw on a spare gear selector that I had lying around

But went to try something, which was to put it in gear and pulled the clutch without the engine running and roll the bike along... (tried 1st and 2nd, then rolled it more and put it into 3rd and 4th)

Seems like there's a lot of drag as soon as I engage gear, even with the clutch lever pulled in. The drag seems to disappear after rolling the bike a bit... reappears after I release the clutch lever and pull back in... seems like it might be super sticky clutch plates or the clutch isn't disengaging properly...

Drag feels a lot like the beginning of my lock up...
Is not that bad. There is wear but fairly average wear. However, with higher power in the 30+ bhp range, really don't want any play in anything gearbox related.
That closes the investigation on gear selecting for the cause of the lock up.
Clutch is either on, off, grabbing or slipping, but no state will lock the rear wheel enough to fall off and leave the engine running.
Something loose in there. Primary catching on the clutch, can you rule that out?
UTC

Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: UTC
Posts: 4437
Location: London UK
 
Jet Eye Master
PX221 MHR, O tuned PX200, PX181 Quattrini and some motorbikes
Joined: UTC
Posts: 4437
Location: London UK
UTC quote
charlieman22 wrote:
Quote:
How do you service the small arm? Seems straightforward but I couldn't unscrew the small screw on a spare gear selector that I had lying around
Have experienced the same thing. No chance the small arm screw will come on done. (Used all my tricks)

Does anyone have some specific experience with success in unscrewing that little screw?
Screwdriver in slot and turn usually does it. Have to get the hammered over casting off first though. They really don't want them to come undone.
OP
@108 avatar
UTC

Ossessionato
PX 200
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@108 avatar
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UTC quote
Jack221 wrote:
charlieman22 wrote:
Quote:
How do you service the small arm? Seems straightforward but I couldn't unscrew the small screw on a spare gear selector that I had lying around
Have experienced the same thing. No chance the small arm screw will come on done. (Used all my tricks)

Does anyone have some specific experience with success in unscrewing that little screw?
Screwdriver in slot and turn usually does it. Have to get the hammered over casting off first though. They really don't want them to come undone.
So cut the arm off and then unscrew? I imagine need the vice grips on it...

Was wondering if an impact driver would work, but don't have a bit small enough
OP
@108 avatar
UTC

Ossessionato
PX 200
Joined: UTC
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Ossessionato
@108 avatar
PX 200
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Posts: 2305
UTC quote
Jack221 wrote:
108 wrote:
Went to double check the small selector arm play, it has some, but it's no more than 0.5mm (if that)

Here's a video of my thumb pushing the arm towards the right side of the engine...

How do you service the small arm? Seems straightforward but I couldn't unscrew the small screw on a spare gear selector that I had lying around

But went to try something, which was to put it in gear and pulled the clutch without the engine running and roll the bike along... (tried 1st and 2nd, then rolled it more and put it into 3rd and 4th)

Seems like there's a lot of drag as soon as I engage gear, even with the clutch lever pulled in. The drag seems to disappear after rolling the bike a bit... reappears after I release the clutch lever and pull back in... seems like it might be super sticky clutch plates or the clutch isn't disengaging properly...

Drag feels a lot like the beginning of my lock up...
Is not that bad. There is wear but fairly average wear. However, with higher power in the 30+ bhp range, really don't want any play in anything gearbox related.
That closes the investigation on gear selecting for the cause of the lock up.
Clutch is either on, off, grabbing or slipping, but no state will lock the rear wheel enough to fall off and leave the engine running.
Something loose in there. Primary catching on the clutch, can you rule that out?
Yeah I didn't think the play was that bad... the play on my other spare gear selector is pretty bad... you can fit a toothpick into the hole where the pin goes in...

Looks like I'll be fishing around the clutch... will be using a small mechanics mirror to see if I can spot anything, but I'm contemplating splitting the cases to swap out the primary and driveshaft
OP
@108 avatar
UTC

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@108 avatar
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UTC quote
SoCalGuy wrote:
Start with the clutch ...
MJRally wrote:
Yep. Check the clutch. See if it blew/ loosened up on the crank.
Looks like its the next point of call to pull the clutch.

Its been bulletproof so far the CR80 plates arent too old i reckon between 300-500kms on them, most of that on a rotary setup.

I'm hoping its the primary...
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