It finally stopped raining here long enough to mow for the first time and the grass is very thick and tall. I serviced, greased, tightened bolts-all the things done before first mowing. My 18G started right up and went through the grass with no problem. My 20g, the one that had all the problems last fall with the pto replacement at the Gravely dealer, started ok and mowed ok. After shutting it off so I could test drive my Troy-bilt Horse tiller, I went to start the 20G to put it in the barn and the starter just spun quickly but would not engage the flywheel. I found by trial and error if the starter gear is moved back and forth on the shaft a few times the starter will engage properly-but only once.When you try again after the first start the gear will once again not engage. The starter is new from Pats Small Engine Parts, and it was only used last fall to start it to take it back to the dealer so they could install the proper pto parts. I am guessing 5-10 starts on the starter. Has anyone had this problem before? The battery is fully charged, and I lubed the starter shaft with graphite spray and the teeth on the flywheel appear to be ok(the tractor has very low hours). Any help would be appreciated.