My brother inlaw replaced a rod in this engine (with no manual) and after assembly, he says he can only get it to backfire with the choke out. I was wondering if he could have got the camshaft/crankshaft timing wrong? He said he ligned up the marks. Is it that simple? This engine (1995) has electronic ignition, so there is no points, correct? Is there some other timing I should be concerned with? I was just going to make sure the gas is good and the plug is gapped a .30. I also noticed a post here "Its possible there was some trash in the float bowl thus when you flipped the engine around working on it some got in the main jet,I have had this happen.Clean the carb. out and see what happens,If this doesn't do it explain in better detail what its doing." I will do this as well. Hope someone can answer my questions: Cam/crank timing? No points to worry about? Any additional timing to be concerned with? Any other troublshooting tips? Thanks much for any help.