2009 second gen with 51k. Planning on doing a Sohn adapter and letting it burn 2 stroke oil, and running a good synthetic in the crankcase. My question is, are the updated oil injectors sufficient, or would premixing in addition still be beneficial (assuming “normal” grand touring type driving, not track or racing usage). I don’t have a problem with the exhaust, but if there’s any engine longevity to be gained by yanking off the cat, then off it comes.

Everything I’ve found seems to be a reaction to the shortcomings of the first gen engine, were these issues sufficiently addressed in the second gen?

 

You'll have a hard time making the Sohn adapter working on a series 2... The OMPs are not compatible and there's nowhere to install a series 1 OMP. You'll need an oil safe pump that can generate 10+ PSI of oil pressure with a 10 PSI pressure regulator and then fittings to plumb to the OMPs, then return the excess oil to the oil tank. It's a rather pricey proposition.

I'm premixing 1/2 Oz per gallon for normal use and 1 Oz per gallon for hard use on my S2.

Removing the cat isn't necessary, but you can sell a stock cat for ~$1000 right now and do a catless midpipe but it smells pretty bad. If the stock cat fails and clogs it's not worth anything and can kill the engine. To prevent that failure, make sure your ignition system is in good shape.

 

As mentioned above, there is no way to fit a SOHN on a series 2. It uses a different OMP setup with 2 pumps. You are better off just premixing the gas. The main issue with the series 1 pump was it only lubricated the sides of the apex seals and not the middle. It was found a high percent of apex seal failure was lack of lubrication to the middle of these seals which accelerated wear in the middle. This is why the second OMP and third injection port were added to address this problem. Whether or not this solved the reliability is questionable. Series 2 engines fail similarly to series 1. I would still premix in a series 2 at 0.25 - 0.5 Oz FD rated 2 stroke per gallon to both provide the extra lubrication while preserving the cat.

 

Fantastic! Good info thanks