LCGB Forums

Hi Guys can anyone give us a clue regarding MPG, I am running a Mugello 198, 28 Dellorto, Power jet with a Augsto 6000. When I first had the Lambretta up and running I was doing around 65miles on a standard tank. Now I am getting around 45 miles a tank a big difference of 20 miles.

The jets are all fine as it has been dyno'D by Chiselspeed, they reported no problems just needed a little fettle on the powerjet.

Had a look around, no spillage from tank or weeps.

Did have a breath sweet on it but makes no difference if on or not, took of as side panel was squashing the elbow on this, (Was still doing 65 when had this off as well).
I do ride full throttle everywhere as do not get out on it much! But then I was doing this in the early days, still get 65 out of it!

Pain in the Backside to keep stopping all the time.

Any Pointers? Thanks in advance.

This must be stumpy a lot of people! As no ideas......

Del.

I have read and re-read your original post. Are you saying that something was changed on the scooter, and now it only does 45mpg? If so, what was changed?

Or are you saying that you have changed nothing, and the scooter is now doing less mpg?

It sounds like your dyno guys richened up the topend via the power jet to keep the fuel mix in the safe rich zone.
Cos you ride it flat out, then expect to consume a lot of fuel, but be reliable enough to have fun on and still expect it to get you home with the piston in one piece.
Fun + Reliability = Deep pockets.
Unreliability = No chuffin fun and even deeper pockets.
How do you like to spend yer money?

Fast n Furious wrote:It sounds like your dyno guys richened up the topend via the power jet to keep the fuel mix in the safe rich zone.
Cos you ride it flat out, then expect to consume a lot of fuel, but be reliable enough to have fun on and still expect it to get you home with the piston in one piece.
Fun + Reliability = Deep pockets.
Unreliability = No chuffin fun and even deeper pockets.
How do you like to spend yer money?

never a truer word said, concerning Lambretta's.

Surely it was running right on the edge getting 65 mpg ,

Hi guys.

Reply to Knowledge, I have changed absolutely nothing!

Fast n furious. I can see what you are saying and makes sense just a right pain in the backs*** to keep stopping, rode to Skegness rally at weekend 51 miles round trip, full tank + 2 litres. ... Crazy. Fuel light was on solid ( Camlam fuel sensor) so had to be steady last 2 miles.

Mel, I have blown 2 pistons before! Hence reason I took it to Chiselspeed to check over.

Was hoping if I renewed slide and jets etc etc might make a difference.

Delboyli150 wrote:Hi guys.

Reply to Knowledge, I have changed absolutely nothing!

Fast n furious. I can see what you are saying and makes sense just a right pain in the backs*** to keep stopping, rode to Skegness rally at weekend 51 miles round trip, full tank + 2 litres. ... Crazy. Fuel light was on solid ( Camlam fuel sensor) so had to be steady last 2 miles.

Mel, I have blown 2 pistons before! Hence reason I took it to Chiselspeed to check over.

Was hoping if I renewed slide and jets etc etc might make a difference.

Ok ... well that does sound a bit steep.
I did have a similar problem with a TS1 that was running with a 40 year old 34mm Amal. Man could it use juice.
The carb was just worn past its best use by date.
The new replacement TMX35 proved it so.
Maybe you need a new carb? They do wear, especially on tuned motors and because its usually wear in the carb body that ultimately lets them down then its generally not worth considering throwing money at them. Bite the bullet and just fit a new one complete.

Cheers, think I am going to have too!

At the moment I am running a 28 Dellorto, not sure to change smaller or go bigger!

Any idea guys?

For a 200 .........28-30mm will keep it tractable and easier to setup and manage than say a 34-35mm.

Cheers Fast,

Been thinking I have only had the Carb around 4 years no more than 15k miles,

Do you recommend using same size jets needles etc or start from the beginning.

As you ask nobody in particular....

Having played about with various carbs over many years & tried to glean as much as I can from tuning books/web sites, I have no doubt that the only real advantage of round slide carbs such as the venerable Dell’Orto PH range only offer the advantage of availability & vast knowledge available from the likes of Lambretta Forums.

However, personally, although I own a couple, there are much better products on the market.

I’m sure you don’t necessarily want to buy the best/most expensive of Dell’Orto’s flat slide carbs, but, there are excellent alternatives. I don’t (yet) run a PWK carb but many do & although they may be a relative minority in the Lambretta field, those that do can probably feel quite smug in their choice as they are a very wise choice, based on price & performance.

Jetted correctly & derestricted (if necessary) the OKO/Koso/Chinese copies do yield performance & efficiency beyond the round slide equivalent.

If you have any doubt about that, check out the many Forums for other two (& four!) stroke engined makes of bike & you will see that they are extremely popular elsewhere....

I've seen similar impressive results from these newer named brands. Probably because they are so new? A bit of research on jets and needles availability would be wise if you're considering a purchase.
Tuned lammy's give carbs a very hard time and if your steed is doing or has done the mileage, then it deserves decent carburation service just like your crank or your piston. These newer brand carbs are quite cost conscience, They may not be as hardy long term but.... you can afford replacements more often!

Hi has anyone got any recommendations for alternative carbs? Regarding the above.

Running a Mugello 198, JL3 along with a Augusto 6000, everything else has been upgraded as well.