Missing the sound of two strokes at modern MX races?

[Rusty]

True, but the smokeless oils just don't smell right 

[tony27]

Rusty this EFI multi point bike, was it a twostroke and what year was this...
They do have production efi two stroke Ski doo's correct
Brett

Was about 2005 from memory & yes it was a 2 stroke.  And yes Skidoo has some trick smokers.  Suzuki, Yamaha and Mercury make 2 stroke EFI outboard motors that are so smooth they make the 4 strokes seem as rough as an old steamer.

One of the things that totally cracks me up is how it is put forward that the compressors are more environment friendly - total BS.  Class for class - a 450 puts out more emissions than a 250 smoker and a 250F puts out  more than a 125.  The thing with the smokers is that, well - they smoke and that leads people to believe they are not good for the environment.

Not to mention the amount of waste oil & engine parts they consume or the extra amount of resources used in producing them in the first place.
 
Not 100% sure but isn't direct injection banned by the FIM which removes a lot of the advantages emissionwise for a 2 stroke, in theory with direct injection you would use a metered oil pump for the bearings etc  & only introduce the fuel after the exhaust port was closed stopping any loss into the exhaust which would also improve economy.
Wasn't the Bimota Vdue meant to have originally been planned to run direct injection but got changed to carbs very late in it's development due to lack of money to sort the set up properly?

[Rusty]

Not sure if it is banned or not - haven't read a FIM rulebook in years.  If it is, I would expect a certain 4-choke company to be at the forefront of that happening.

As far as technical aspects of the trick smokers I got to play on - I was told nothing and my phone was confiscated while I was still in the people mover we arrived in before we sighted the bikes.   However, after a crash - accidently on purpose on the far side of the track  -  I did note what looks like an oil reservoir while I was checking the bike over carefully prior to remounting.

[Slakewell]

IMO the FIM banned direct injection on GP bikes in the 80's to stop costs getting out of control. The reality was the last 250 GP bikes the works models had more or less electronic carbs that cost more than fuel injection anyway. Given that most two stroke scooters have FI and most outboard motors have as well. The FIM should allow direct FI. Honda would hate the two stroke return so it may pressure FIM. If KTM and others just do it anyway I think they sell like cold beer.