Knocking in mower deck or belt clutch when engaging blades, motor bogs / slows down

Check that the blade brake is disengaging. Slip belt off blade spindles and check that they spin freely. Check underside of deck for clogged grass, ropes, wire, etc.

Looks like your mowers have a little age on them. I recommend that you remove the decks for inspection. I bought one recently that the deck was rusted out in the middle causing it to flex and throw the belt. Check for good alignment all around and make sure that the blade guides around the pulleys are as they should be. If not that will cause them to eat the belt. Make sure everything moves as it should including the blade engagement mechanisms.

I hope this helps you get going.

I have a YTH 150 with a similar problem. The mower has an electrically powered clutch which is activated when you engage the blade button. If the drive belt has no tension on it, engaging the clutch doesn't do anything because the drive wheel will just spin but the blades won't. Look for broken tension springs on the mower deck and replace.

check the belt as it bound, if you do not think so then take it off(the belt) and engage the PTO if it does not die then it is: the belt, pulley, or blades are/is the reason why it is stalling Tim

Hi and welcome to FixYa, I am Kelly

See this link and locate your deck:
http://opebycrigby.tripod.com/decks/jddeck.html

Make sure you have the belt routed correctly. ALSO make sure that you do not have it flipped 180 deg over the idler.

I recommend that you unhook the belt from the mower deck pulleys and try rotating the blades. A bad blade bearing can cause a belt to heat up. Of any of the blades are hard to turn by hand that blade bearing will need to be replaced. Check the idler pulley also.

If after checking the above you continue to experience a problem just respond here and I will help you.

Thanks for choosing FixYa,
Kelly

It's possible the repair folks didn't properly reinstall the mower deck belt. Check that it's in place, and under good tension. If that's OK, look at the wires to the mower engagement switch (PTO switch) and make sure the connections are on tight. Then check the motor pulley where the PTO clutch is, making sure those wires still in place.

Could be a broken belt, loose belt (stretched) or something is under the mower deck jamming the blades. (stick for an example)

few reasons will try to narrow down first start it and put in neutral and deck disengaged release clutch if bogs then fuel problem the carb may need adjustment or repair or fuel filter needs replacement----if no bog step on clutch no put in gear release clutch if bogs check drive belt -upper belt on engine pulley and check for binding an idler pulley problem -debris -or rear unit binding -needs service-drive pulley damaged-rear locked--if not bogging in gear step on clutch engage deck release clutch if bogs need to check deck -belts-pulleys -mandrels -bearings and for bent or binding blades good luck

No permanent solution, but you probably can get by once by "riding" the clutch engagement lever - pushing it only part way forward and holding onto it.

Tim, first turn key on engage and disengage blade button. See if you can hear the clutch making a clicking noise. If not check switch., if not your problem is in the clutch.