I use an Outerwears prefilter with my K&N. No power decrease, it helps keep tiny bits of water out and really catches the dust before too much of it touches your filter. I couldn't see going without one.
Thanks for the info. Yellow650, any reason why you didn't go with a K & N prefilter?? Also, any experience with the k & n only? That is the only modification I have (other than ITP radials). It definately increase my low end> easier to wheelie, as well as my top speed>61mph. How can you tell if the spark plug color is ok> reflecting any changes in the carburation?
The Outerwears prefilter IS the K&N prefilter. They are the same product.
If you buy a K&N it will have Outerwears printed on it (at least they used to), it's just that K&N is selling it to you.
If you didn't change the muffler to an aftermarket unit, you shouldn't have changed the mixture much at all.
Spark plug color is a bit hard to establish. It should be tan to light brown, without any traces of white on the deposits. White means too lean. Use a brand new plug and run it hard for at least 1/2-3/4 mile. Shut it OFF without letting is coast down in speed. In other words, hit the kill switch while running wide open and brake to a fast stop. IF you let is slow down on it's own the plug color with change. Also check it after a normal ride, but here used the kill switch also.
With different gas blends around the country and in different parts of the same
state even, spark plug color is not as reliable of an indicator of mixture as it used to be.
The absolute best way to determine mixture is a ring of brown to gray deposits on the insulator, but this is very difficult to see properly. Take the plug out and look down the insulator with a very strong flashlight. If you see no ring around the plug insulator you are too lean. The closer the ring is to the tip of the plug, the richer you are. Ideally, the ring should be 1/4-1/2" below the tip.
Of course, the easiest way is performance. If the bike runs really good and does not overheat on long strenuous rides, you should be OK.
First time I changed my plug it was black from the tip almost all the way up the threads. It seemed to run OK. I don't know if it will wheelie or not. To old to find out... Just use it for trails at Windrock. Don't like to go real fast so don't know top end. I do sometimes blow it out but not alot. At that time we adjusted the valves and they were a half turn out according to the book. That was last week and I have ridden it once, only for about an hour or so and only maybe 9 miles. Seemed OK. What would the black plug indicate? Too Rich????
Sorry if I asked in the wrong place...