LCGB Forums

Afternoon a bit off a dilemma last year I attempted to ride to eurolambretta well I did quit well I got from lancing to Barcelona on the way I had about 10 break downs on the way eventually missing the ferry when back home took off head checked the piston a couple off tiny marks on it gave it a clean and barrel then had it dynoed it’s a jet 200 engine 25 mm dellorto mb pipe and it’s 4 th oversize that’s as much as I know . Running fine starts first kick and runs today I get 10 miles out off Worthing cuts out on me no skid just loss of power as on the Spanish trip any ideas ?

Loads of ideas......

Gummed up rings can cause loss of power. Worth taking the barrel off and having a look. Check bore and piston clearances while you're at it.

Could be stator breaking down......easiest way is changing for another stator.

What's your fuel flow/rate ? get a litre/pint container and check flow rate.

carb' could be an issue...blocked jets, sticking float, etc. Give a clean and check for anything amiss......

air filter may need cleaning, have you tried running open mouth ?

What's your plug colour like ?

Plenty more suggestions but that should be enough for now.

Stator.

Thanks have checked carb etc does the stator break down when hot ? Or randdomly

Just had dynoed when cooler weather and was running fine but the same as in Spain when warmed up bit off pressure and would shut off no skid no force on the engine just clutch and coast out the way then start back ion mad feels like ran out off fuel

I had something very similar. Chased around with carbs, jets etc as it seemed like a fuel issue. Changed stator and problem sorted.

I would post a link to thread but don’t know how Search ‘dying engine’ if interested.

Tony did your scooter cut out when warm or any time??

kilsh1968 wrote:Tony did your scooter cut out when warm or any time??

It was always after the engine had warmed up but could be after five or ten miles when it cut out. Some days I managed to get to work without it dying at all but the next day it would be back. Just done the C2C on it at the weekend and apart from refusing to start due to a duff plug on day one it ran for 500+ miles without issue.

Tony,

Re the above post. You do not have a problem, you have a Lambretta.

A simple check is that the petrol cap breather is not blocked, I know of someone who changed all of the above and would still cut out...his waterproofs under the seat was blocking the breather on petrol cap...been fine ever since!

Similar thing happened to me yesterday.
Had been difficult to start a few days ago but was fine before and since, first kick every time.
Yesterday she fired up as usual then about 6 miles into the ride home it felt like it was losing power then just died.
Plug a nice dark brown but dry looking, nice enough spark. Fuel flow to bowl fine, jets not blocked, compression seemed okay.
Tried bumping her but nothing apart from the odd backfire.
Pushed her to a petrol station, tried new plug and cap, green wire out, unscrewed filter and easy start down the carb. All I got was a few loud backfires out of the exhaust when kicking.

Anyway, would a failing LT coil still give me a decent looking spark or should I be looking elsewhere first?

Marty ULC wrote:Similar thing happened to me yesterday.
Had been difficult to start a few days ago but was fine before and since, first kick every time.
Yesterday she fired up as usual then about 6 miles into the ride home it felt like it was losing power then just died.
Plug a nice dark brown but dry looking, nice enough spark. Fuel flow to bowl fine, jets not blocked, compression seemed okay.
Tried bumping her but nothing apart from the odd backfire.
Pushed her to a petrol station, tried new plug and cap, green wire out, unscrewed filter and easy start down the carb. All I got was a few loud backfires out of the exhaust when kicking.

Anyway, would a failing LT coil still give me a decent looking spark or should I be looking elsewhere first?

What Engine Marty ?

Gt 186
I see you've suggested it might be the reeds on another forum. Cheers, will take a look tonight.

Marty ULC wrote:Gt 186
I see you've suggested it might be the reeds on another forum. Cheers, will take a look tonight.

It happened to one of our lads same set up 8 miles
From home

Marty.
Could be a sheared woodruff key on flywheel. Well worth a check.

As Mick sez,
+1

Okay story so far.
Checked cdi connections, all good, attached spare and she just backfired, it was dark so the I saw an impressive flame coming out of the pipe
Multimeter readings on stator spot on.
Flywheel off, woodruff key looks mint as does the stator, no obvious burning /chafing /looseness all the connections look to be sealed.
Looked down the manifold as best I could and it looks like the reeds are still in place.
The flywheel was very easy to turn by hand though so I wonder is my next job to pull the top end off rather than try my spare stator?

I'll check the reeds properly first.
Hopefully that's it I can't afford another wrecked barrel this close to euro.

Marty ULC wrote:I'll check the reeds properly first.
Hopefully that's it I can't afford another wrecked barrel this close to euro.

Marty reed block off first its looking that way

Ring peg has come out, left a deep gouge on the inlet side and looks like it's pushed the piston against the opposite wall of the barrel fusing the rings into their grooves.
Less than 3.5 thousand miles on the kit.