I am having issues with my 2006 honda trx500fe electric shift (800 miles). It will not shift from neutral to 1st or 1st to 2nd or back to neutral at times, other times I have no issues. If I rock the atv a little while pushing the button it will then shift. I took it in last summer to an atv shop to have it looked at and standard maintenace done but nothing was found? Any ideas?