TS1 jetting query

[TS1-200]

Been running my TS1 in various guises for 15 years or so current setup is 60 mm crank, 116mm rod,Racetour piston, 34 mm Delly, NK pipe, performance is good, query, I have been plagued by a mid range light throttle opening (45- 55 mph) spluttering which I have put up with, but chatting to someone recently he suggested I try a weaker atomiser, currently DQ268, K38 needle top clip, 170 MJ. On his suggestion I have fitted a DQ266 atomiser and I must admit it is better, obviously weaker but how much a change is this mixture wise, done some low speed plug chops and seems fine, any advice, will have to get out on the by pass to do some proper plug chops.

[Warkton Tornado No.1]

Lambretta large block engines, by being compromised massively due to developments over the years whilst Innocenti stuck rigidly with the basic crankcase, crankshaft & over-square arrangement, shake like a sh*tt*ng dog, particularly when tuned by increases in capacity &/or PPM.

Therefore, the needle of the carburettor rattles around in the atomiser.

Both get worn in no time.

Lambretta enthusiasts seem to overlook this fact, but I’ve made such oversights myself.

Often a fresh needle & atomiser will restore the performance of an engine that has become rich.

However, IMHO, the Main Jet size you quote as 170 sounds HUGE to me. I would have expected the MJ to be in the 140 - 150's but 'horses for courses' & all that