i've got a grubee starfire gt4 with at least 1500 miles on it, probably a lot more. been going strong for 4 months (i think) only major probs was 2 busted chains (not my fault, just crappy chains.)
i have about 100 miles on my engine probably but most of the riding is short 1 mile rides around my yard so the engine dosen't really get that hot. I use about 32:1 but only add 1 liter at a time,(easier to mix) the more gas you add the (leaner mix) the more speed you will get, but it may seize up or hurt the engine. Also use 2 stroke motor oil it is often sold in small bottles and is specifiably to run in a 2 stroke engine
My last one lasted for over 8000 miles,currernt one has about 1500 on it.I ride daily around 15-20 miles or so.Except for break-in,im WOT every time I ride.Had to change the magneto on the first on,so far so good on my current one.I just recently started on build 14.Pulan Synthetic from Wal-mart at 32:1.
my original MB i had over 2500 mile BGF and ran. 34t rear sprocket max ever toped was 41.3 no bull the some decided to steal it just 40 miles a 1 month of work to fit the engine on a trek 6000 and SBP tuned pipe. my second kit right now and i have almost 400 but the thing im worried about it the chrome coting on the inside of the cylinder is chipping off has any one else had this problem with grubbee engines?