I have a 3700 AV in Craftsman grey rhat runs when it runs, but hard starts at times. Good spark, just cleaned carb and put in new diaphrams. I can't seem to tune the hard start out. Actually got it going the other day and tuned it like a beast. 1 pull start and idled great. Then 30 minutes later it wouldn't start. I"m guessing it would start better with more compression. Anyone know what the spec for compression on this saw is.