Changed mine in my Z800 at 75 miles then again at 200. Along with the differential fluid each time. Going to go from the recommended intervals from now on. I also changed to the UNI filter. At the 75 mile period. Should have been 74.9 miles sooner. Lol.
My plan is to change engine oil & filter and diff oil at 50mi and again at 150mi then go to engine oil & filter at every 500mi and diffs every 1000mi unless I start doing a lot of trail riding then I would space it out more. As for now it will be doing mostly what the book calls "severe use" for prolonged low speed/long idle time (spraying pesticides and stuff) and heavy towing (pulling a trailer gathering brush and whatnot). All the things I think would fall in the category of things you expect a four wheeler to do. But what do I know, I didn't write the book LOL.
I just did my first service at 46mi and had already put in a uni air filter at around 8-10mi.
I was very disappointed to find that the rear diff was 1/2" below the fill hole and none of the pivot points on the rear swing arms had grease in them. I'll be letting the dealer know about it tomorrow.