Small Engines (Lawn Mowers, etc.): string trimmers, string trimmers, bolens

Question
1st---What is the gap for the ignnition module on a Bolens BL 250?
2nd---Ryobi 790r will not rev up like it should and it makes a knocking sound like a rod but everything is tight
with no sign of wear.

Answer
 Hello Lanny:

 1- The Gap is .010in. 2- Check the Exhaust Port for Blockage. Check the Muffler and Spark Arrestor Screen for Blockage Also. Check the Top of the Piston for Carbon Built Up. and Slapping the Top of the Jug. Hope this Helps. I am here if you Require more Assistance. Let me know what Happens, Please. Thanks.

 Good Luck

 Respectfully

 John