One thing everyone needs to remember to ask is.
How much hp will I gain?
With most trail sleds with few mods going from .070 to .060 squish will pick up 1~2 hp. Thats added to all the power band with maybe a 10% chance of a poss problem from that mod.
Now go from .070 to .050 and gain 2~5hp and now the odds jump to say 40% to 60% that some problem or issue may come from that mod.
Same with jetting. Going from 143's to 141's is a 2~3hp gain, 10% odds some issue may come from it.
Going to 143's to 135's is a 3~5hp gain, but the chance of a problem went WAY up.
Going to the edge on both may give you a total of 10hp gain, keep it safe and still have 6hp.