I got a 95 Kodiak 400 the other day has been sitting for 2 years.Guy says it ran when he parked it so I drained fuel,cleaned carb and put new plug and battery in it.Nothing,will not start,does crank over fine.I think the compression is low(going to test today)what should it be?If it is that how hard is it to put a new piston and ring in it.Also,what is the plug gap supposed to be?Thanks for any help.