I am surprised by the 136" track (unless this was added later). If it truly is a '99, I own the 121" version of that very sled. The 1999 MXZ 700 was a mid year release of the new 700 twin. Published numbers at the time put the hp at 126 which was about 4 hp more than the production 700 in 2000. It had the "new" ZX chassis but the old SC10 rear suspension with ACM. Lots of folks put on the ETS kit to get the fully coupled performance that came stock in 2000. I have ridden both and honestly can't tell the difference. This motor has been rock solid for me and surprises an 800 in 1000' every now and then. I paid $6200 for mine as a leftover in 2000. All in all....no complaints here.
1999.5 MXZ 700
1991 Formula Plus (It just won't die!)