tdi-rick
Addicted to ArboristSite
As the boys above have alluded to, inertia (weight of rotating/reciprocating assembly, particularly the distance from the crank centreline to the OD of the mass) has a huge bearing on acceleration, as does the LS and transition circuit on the carburettor.
Everything is a compromise. Like everything else, increased inertia and the flywheel effect have pro's and con's.
The con is acceleration, the pro is perceived torque, the greater the inertia, the better an engine can maintain torque under load at a given revs.
Seeing as no one has flywheel, clutch and crank weights and dimensions, has anyone had a serious play around with the LS circuit on the 5100S ?
All initial acceleration tuning on a two stroke engine is done on the LS circuit, the LS is generally enriched until the engine 'snaps', if you go too far it stumbles. If it's too lean at low revs, it just accelerates slowly.
Yes, yes, I know the 5100 revs to 14,500, but when you snap the throttle, the LS/idle and transition circuits supply the fuel from idle revs until there is sufficient velocity across the main jet to drop the pressure enough to allow fuel to flow. (venturi effect)
If this depression equates to somewhere between 10,500-12,500 RPM, all the fuel requirements below this must be met by the LS and transition circuit.
A combination of LS tuning and pop off pressure adjustment may overcome some tardiness in acceleration here, if indeed that is what causes the 'lack' of acceleration.
Everything is a compromise. Like everything else, increased inertia and the flywheel effect have pro's and con's.
The con is acceleration, the pro is perceived torque, the greater the inertia, the better an engine can maintain torque under load at a given revs.
Seeing as no one has flywheel, clutch and crank weights and dimensions, has anyone had a serious play around with the LS circuit on the 5100S ?
All initial acceleration tuning on a two stroke engine is done on the LS circuit, the LS is generally enriched until the engine 'snaps', if you go too far it stumbles. If it's too lean at low revs, it just accelerates slowly.
Yes, yes, I know the 5100 revs to 14,500, but when you snap the throttle, the LS/idle and transition circuits supply the fuel from idle revs until there is sufficient velocity across the main jet to drop the pressure enough to allow fuel to flow. (venturi effect)
If this depression equates to somewhere between 10,500-12,500 RPM, all the fuel requirements below this must be met by the LS and transition circuit.
A combination of LS tuning and pop off pressure adjustment may overcome some tardiness in acceleration here, if indeed that is what causes the 'lack' of acceleration.
