Does breaking the engine in -- in the winter worse for it than in the summer
the winters here our About 20-40 F here

Heard someone talking about it is hard on it
just wondering because i just broke in my grizz with 21 hours

 

Breaking a motor in in the winter is fine as long as you allow a little warm up time before you ride. The number one thing during break in is to avoid excessive heat build up inside the engine due to excess friction as parts wear in. This should be easier to due in cool weather. Just don't run it hard in deep snow. Also 10w30 oil is a good idea during break in because it flows better in tight clearances. Just check the level often. You should probably change the oil and filter now (you said 21 hours) and again around 50 hours. Then change it at least every 50 hours. Hope this helps. Enjoy, the griz is an awesome machine.

 

Just changed oil in it today and used a Fram oil filter with yamalube 10w30
don't like the idea that yamaha put the filter to the side so oil drips all down the engin
still love the grizz

 

It's an ATV. It will get much dirt, filth and muck on it if you pleasure it like most other riders. The small amount of oil from the filter isn't squat.