I am finding it getting harder to also volunteer my time and money towards the sport. Being retired I need to watch what I spend. In the past I would pay for the odd items out of pocket for our club and not other submitting the receipt. A trip to our shop is 60km round trip and diesel is creeping higher and higher weekly. This BS in the US needs to stop so all can go back to normal. 

I dont notice much difference from a 129 to a 137 but I sure like the fact that the 137 has another set of Linq clips.    That alone is reason for me to go with the longer track.  

And pull start a 2 stroke if equipped with pull cord

2 stroke or 4 stroke?   Front end weight makes a difference.  FWIW. Had a 146 Pantera 7000 and the "flickability" between it and a 137 ZR9000/7000 are marginal. Ride was good with both, probably a bit better with the Pantera. The Pantera did push more in the corners tho, even with the 2up seat and bags off. Added note, my wife preferred driving the Pantera than the ZR7000iACT she has now.    Can't compare to a newer 2 stroke as I have no experience on them. I still miss my old Sabercat 700. Worked great everywhere. Bonus is you can actually pick up a 2 stroke if it gets stuck.😉      

If anything I would tip toe into at 137 - think 129 to 146 may be too much and could prove to not be to my liking. I am a guy who likes very little change - and usually am quite comfortable sticking with what I know works and what I know I like. Going to a 137 would be a huge thing for me mentally