Bunton Twister - blades making contact

   / Bunton Twister - blades making contact #1  

thartweger

Bronze Member
Joined
Nov 28, 2008
Messages
58
I have a Bunton Twister. It is around a 1997. I recently purchased some blades to be put on the mower because that ones that were on it were really worn badly. The old blades were worn so much, they are 1/4 inch shorter then their original length. I am assuming they are this much shorter due to comparing them with the new blades i ordered which are 21" blades, although when I measure them they arent a full 21 inches, although I dont think they are supposed to be. The model number on blade matches the one I purchased that show having the exact specs as the OEM blades.

OK, now that I have made sure I purchased the correct blades, I begin to install the left and right sides. I cannot yet install the center because they were on backorder and have yet to ship it. Either way, this is a good thing because here is the deal. I should have just rotated the blades under the deck first to see if they were touching, but they were real hard to move so I just installed the LH RH blades at 9 and 3 and left the center blade at 6 and Noon thinking that would keep them timed or w/e. I started up the mower and engaged the mower deck it the lowest of RPM's. I hear clanking, I shut it down.

Im now anrgy, lol.

After the anger subsided, I sat down and began to think that it might be a warped deck, but after dropping it down to the pavement flat, it all looked symmetrical to me. So I am seriously thinking now that a spindle is bent. I have never had this issue, so I figured id look for help. I cannot find anything on a Bunton Twister anywhere really. I do have the parts manual. Original OEM spindles are the price of what NASA would probably put on a rocketship.

I have noticed that the blades when turning them arent always flush with the bottom of the deck as they should be. Sometimes the blades willl travel up into the deck while the other side of the blade is coming below the deck.

I noticed the LH blade drops below the deck on the backside of the deck. This blade doesnt touch the center blade but appears spindle might be bent?? Also keep in the mind the middle blade hasnt been replaced yet, so they may touch when the new one is in.

I just now went out and double checked the RH blade, the one that was clanging with the center. I have since then ground the center one down and cut for now till I can get it figured out. Either way, back to the point. The right hand blade starts to come up inside the deck at about 8 o' clock. Which to me would mean the spindle is pushed in that direction as well?? If this is the case is this what would be making it hit the center blade?

As far as the center blade goes I have not checked to see if it goes up and below the deck. It could very well be bent towards 4 o' clock, I do not know yet.

With all this being described, are my blades hitting due to the fact of a bent spindle? Are my blades too long even though they are within specifications of OEM blades? Could my deck be bent and I just not see it?

Obviously now that I was questioning whether or not the issue on the LH side wsa normal or not, I now realize it isn't due to the fact that the RG side is completely different. I do know though that all my other decks that I can remember the blades are flush right? Either way I will let you guys decipher. Hopefully somone has some helpful inforrmation. Also, if you know where I might be able to find a spindle for this, let me know too. It IS a 61 inch deck and I do see sealed spindles for sale on the net for 61" decks I just dont know if they would work. I would assume they would being as the blades for such decks are all the same length, but again I have no idea.

I have been getting into tinkering with alot of things lately and I am loving the learning experience. Have yet to encounter this one nor have to remedy it. We will talk to ya later. I am going to go possibly take one off.
 
   / Bunton Twister - blades making contact #2  
problems like this are exactly what scares me about buying a used ztr mower: or about any used mower to be honest: folks can think they are taking really good care of a piece of equipment an still have issues like this that they don't know about. good luck, i am looking forward to your solution..hope it turns out cheap an easy.
heehaw
 
   / Bunton Twister - blades making contact #3  
It sounds that you have one of two possible problems. One is that the spindle bearings are going out and you have some slop in them causing the blade to move from side to side. The easiest way to check this is to remove the belt that rotates the blades and check the blade movement by moving one end up and down. You should have no or very little movement up and down at the blade tips. If you do then you will need to replace the bearings in the spindle or the whole spindle. If you have movement, then align with the other blade and see if you can get them to touch buy moving up and down.
Number two on the list is more difficult to find and that is a bent deck where the spindle is mounted at. I just repaired a JD deck that had this problem and I had to remove the whole deck to find this out. I removed the spindles and checked mounting holes with a straight edge. I then had to reinforce the mounting holes with more metal to straighten it out.
Good luck, and lets us know what you find.
 
   / Bunton Twister - blades making contact #4  
Looks like you are getting good advice here from "Johnagain", but since you only have 2 new blades the best thing to do is mount the 2 new blades on spindles next to each other and check if there is a measurement issue - the correct blade for your unit depends on the model - simple way to check is if it has a metal gas tank by the opperators feet then you need the pl4207 blade(21") or if it has plastic fuel tanks over the wheels you need the pl7441 blade (20.5"). both blades have a 5/8 center hole. and should measure 2.5" in width.
If the deck skin is bent it can usualy be bent back with a large 3" pipe about 4' long with a chain or strap about 10" from the end. bolt the chain to the spindle bolt hole closest to the bend and bend it back straight.
Just one more note when measuring the blades-measure from cutting tip to cutting tip on an anglethis is the longest measurement you can find on the blade.
GOOD LUCK, i hope the blade measurement issue is the problem - its a lot easier to change the blades out.
 
   / Bunton Twister - blades making contact #5  
FYI, a mower blade is measured from tip to tip.
Below are directions shameless copied from Hyperparts.com:
Measuring Lawnmower Blades:
  • Measure the length diagonally from cutting tip to cutting tip.
  • Measure the width at the widest part of the blade.
  • Measure the center hole.
Measure_blade.jpg

HTH

Aaron Z
 
 
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