View Full Version : Blades won't turn off on Bunton WB
04-10-2010, 09:30 PM
I have a early to mid 90's Bunton Walk Behind and the blades will not turn off. It is a pull start and the blades are engaged when i start it even though lever is in the off position. Any suggestions would be greatly appreciated. :usflag:
04-10-2010, 09:46 PM
I'm assuming it's a hydraulic clutch, in which case it's probably a bad switch.
Try unhooking one of the cables and see if it will let go.
But you said a lever?
What the hell ...
Have you tried pulling it the other way to see if it will disengage the belt?
I mean you're going to have to pull the deck cover off and see what is down there,
the entire mechanism isn't too complicated, might just be stuck or a piece broken.
04-10-2010, 09:50 PM
Electric Clutch or manual? Makes a big difference. I have owned both (Buntons) I can help you - but need to know which.
04-10-2010, 09:55 PM
I'm no mechanic by any means but here is what I am seeing. The lever is connected to 2rods down to a tensioner pulley??? When you engage this lever the pulley then tensions the belt from the crankshaft to the middle blade. Then another belt is underneath the middle blade spindle which runs to the other two blades. When I try and pull start the mower the belt from the crankshaft to pto to middle blade spindle is turning therefore all blades are turning as I am trying to start the machine.
04-10-2010, 09:56 PM
04-11-2010, 09:21 AM
04-11-2010, 09:38 AM
OK there are several belt guides along the path of that middle belt (from the engine to the middle pulley/spindle). There are two on the deck near the pulley and there are a couple underneath the engine deck. My guess is that one of these have loosened up and moved out of place..... or that the belt has slipped over one of these guides.
Check the belt path to see that this has/has not happened. If it has, you'll need to loosen the guides with a wrench and then re-position them. To do this you'll need to engage the blades and then adjust the guides so that they are about 1/2 inch away from the belt (when tight/engaged). When the blades are then disengaged, these guides will them force/slack the belt off pulleys. This adjusting process is not an exact science - you may need to play with these adjustments to get the slack and tension just right.
Note: There is also a threaded rod that runs down to the bellcrank on the deck (that tensions the belt). There is an adjustment here that you can play with too. You'll need to pull the lynch/hitch pin out and loosen/tighten the nut - again, you'll have to play with this adjstment.
Post your results/questions back here. Hope this helps.
04-11-2010, 09:54 AM
If all else fails, take it to the shop.
04-11-2010, 10:47 AM
OK, here is what I have. I am assuming the belt guides are suppose to be outside of the belt itself, which they are. I played with a few adjustments and it looked like the tensioner pulley on the deck was possibly contacting the belt a little too much. So I had my wife push back the tensioner pulley so there was no tension on the belt at all. I started the mower and it started pretty much as it should but the belt is now sqeeling where the belt goes underneath the engine. So I guess I'm trying to figure out why this belt/pulley are turning when I start the mower???
04-11-2010, 12:04 PM
Is this a new belt or has it been replaced recently?
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