Ser 3, how to reduce 150cc to 125cc

[Paulusgnome]

I have purchased a Ser 3 Li150 from a dealer who imports from Italy, all good, paperwork all done etc....however I want to reduce the engine capacity from 150cc to 125cc to allow me to ride on 'L' plates after taking my CBT, can this be done DIY & taken to an engineer to certificate? If not, what's the cost to have it done, the engine runs & is good?

[MickYork]

Find a 125 barrel (stud spacings are the same) and piston and swap them over. A letter from a reputable dealer/garage will be enough for DVLA. My friend did it last year, no problems. Might be an idea to check with the garage first to see what they require (you don't want them stripping the engine down).

everything's DIY but that depends on the person doing it......buy a "Sticky's" manual and you're half way there.

Maybe a mornings work if things go ok.....price dependant on labour charge and cost of parts.

[Knowledge]

To be honest, I would submit an application to the DVLA stating that there has been a change of capacity,. See if they come back and ask you for proof. They probably won’t.

It is up to you if you actually change the capacity. I have forgotten how many times I have asked on this forum if anyone has ever had an over-sized barrel checked, either by DVLA, the police of an insurance company. There has always been a deafening silence.

And while I am on my soapbox, why does no one make a performance 125 cylinder conversion? A standard cast iron 125 barrel is a liability on a modern road (and a standard 150 is no better).

The very best advice is to pass the motorcycle test, for all the right reasons.

[citydaz]

I recently got a 215cc kit fitted to my other scooter by a dealer.
Wrote to the DVLA to tell them, figuring whats the big deal going from 200cc to 215, since i have already passed my test and there is no change in tax, but the buggers wrote back saying they needed a letter from the dealer confirming the change.
No big deal getting this done, but to my mind im not breaking any law since its insured as a 215cc and i have told them its a 215cc.

[Tractorman]

I changed up to 225 when I fitted the sidecar and contacted them and they just accepted it.

[dickie]

To be honest, I would submit an application to the DVLA stating that there has been a change of capacity,. See if they come back and ask you for proof. They probably won’t.

It is up to you if you actually change the capacity. I have forgotten how many times I have asked on this forum if anyone has ever had an over-sized barrel checked, either by DVLA, the police of an insurance company. There has always been a deafening silence.

And while I am on my soapbox, why does no one make a performance 125 cylinder conversion? A standard cast iron 125 barrel is a liability on a modern road (and a standard 150 is no better).

The very best advice is to pass the motorcycle test, for all the right reasons.

I've never owned a 125, but I didn't pass my test until I was 23. Does it make me a bad person? Who cares? Maybe things have changed but they never checked in the 80s/early 90s.

[Paulusgnome]

Many thanks for all the responses I've had, I now know there are various options..........but taking the 'least line of resistance' I'll just submit a change of capacity to the DVLA, see what that brings forth thanks again to: Knowledge, Dickie & MickYork

[Rich Oswald]

For whatever reason, the DVLA seem more concerned about going up in CC rather than down. As always with DVLA it is pot luck depending on their agent who processes it.

Rich'

[Paulusgnome]

Thanks Rich, my V5 is in the post.............I'll let everyone know the outcome.........

[Knowledge]

Good one Paul.

Keep posting on this, and anything other questions you might have.

We are all here to offer our (differing) opinions.

[citydaz]

DVLA returned my V5 today,
With the original cc re-instated.
Since wimbledon has just started Im tempted to start play "V5 change the cc" tennis with them!

[davla]

Changed the CC on my V5C from 150 to 200 no problem. Just wrote 200 on the change section, signed and send it off. Came back updated in about 10 days.

[Fast n Furious]

Technically, the DVLA require notification with evidence of any change in engine CC.
What they don't clarify is the tolerance.
EG. a standard 200 is actually 198.455cc. So... depending on where you draw the line..... the 200cc rating on your V5 is wrong to start with!
Back in the day, 67.4mm was the maximum oversize with an AE piston making it 206.963cc. Did we notify this change? Did we hell. Never crossed our minds.
So..... at what point would you or should you notify?
Has anyone got any genuine "falling foul" horror stories to regale regarding oversized cylinders?

However..... converting down to 125 would be an issue, simply because it invites a change of tax band and that automatically raises eyebrows sometimes.

Lets hope they never introduce an "over 200cc" tax band.........That would cause some bother.

[burnside]

I recently changed the cc on the V5c for one of mine from 125cc to 205cc (along with a colour change) just with a note explaining what changes had been made and that they were done by myself, I got it back without any questions asked....not sure why they would question an increase in cc more than a decrease? But I do think it is luck of the drawer

[Paulusgnome]

Hi all, just got my V5 back from DVLA, changed from 150cc down to 125cc, I didn't have to supply anything to verify it ie; explanatory letter, engineers reports, inspection certs......got the same engine/chassis numbers, next step is my CBT test, insurance, L plates..........Whoops!! and of course rebuild 'Etta' the Lambretta, named after one of my favourite female soul singers.........once a Mod, always a Mod........thanks for everyones help with this.

[EddieStone]

I'd seriously consider using this an excuse to get your license. It might not cost much more than buying a barrel, head, cylinder and piston and paying someone to fit it and get it running properly. A 125cc Lambretta is dangerously slow and that will spoil your enjoyment of it.

By getting your licence you'll be able to carry a pillion, increase the capacity of your bike whenever you like and ride on motorways. In Europe there's a 150cc minimum to ride on main roads (the reason they make 150s rather than 125s) so if you ever plan to ride there then riding a 150 is useful.

I'd save the money spent on reducing the capacity of your scoot and get your licence, it's only ever going to get harder to get it!