im getting a trailtech computer and i dunno what to put in for wheelsize for my kfx400.. does anyone know what to put in?

 

it should come with instructions on how to measure the tire.

 

Use a flat, hard surface (e.g. driveway, sidewalk), and a piece of chalk or a marking pen.

Mark the sidewall of the tire and the ground at the same point. Roll the vehicle one full revolution until the mark on the sidewall returns to the ground (Tip: for best accuracy, have someone push you while your weight is on the vehicle.) Mark the ground again.

Use a tape measure to calculate the distance between the two marks on the ground. If the measured units are inches, multiply by 25.4 to convert to millimeters.

front wheels of the KFX400: 1676mm is the correct number to put in on stock tires , I install these speedos at work all the time , the best metod of doing it is like it states above but if you have new stock tires on your KFX400 then you can go with 1676.
hope this helps you.

 

oh i did it the other way where u measure the height of it then converted that to millimetres and then times that by 3.14 and i got 1491 or something around there

 

You did it right but you have to multiply that number by 25.4 not 3.14