Neutral shifting is OK for the first 10 minutes of riding, then it's hit or miss after that. I have to squeeze the clutch hard to get it to bite. Honda guy told me this is a Suzuki thing but I don't buy it. Any advice? ???
Honda guy is jealous. Check the adjustment (free play < .5") on your clutch. Also make sure clutch linkage and clutch cable are clean and/or lubed as specified in the almighty manual. Your SV should shift quite smoothly...
That was going to be my question. Remember that the engine and gearbox share oil and if the oil is past it's best then shifting is going to become difficult. The fact that it only becomes an issue after the bike is warm indicates that the viscosity agents in the oil have broken down to the point where they can't do their job properly anymore. Go do an oil change, check your clutch adjustment and you should be laughing.
That's a very important point that I forgot to mention. DO NOT ever overfill the oil. This is not good with the pressure increase on internal componentry, especially given the revs the bikes operate at.
You may wish to consider using a different type/brand of oil. I'm not familiar with Shell Rotella (Probably under a different name here) but ask around.
Rotella is great oil, imo. Make sure you have the right level + or - and then make sure your clutch is properly adjusted as mentioned already. I played with my clutch adjustment at the handle bar today and got the bike shifting with much less effort then I was previously using, I was suprised at how little of an adjustment made a nice difference.