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want to change lawnmower engines


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07-11-08, 08:24 AM   #1  
want to change lawnmower engines

i would like to change engines on my lawnmower.the briggs 14.5 on a mtd(42 inch cut) is blown.i have a murray 12.5 (40 inch cut)briggs that runs well.i asked on another place and it said to take measurements of bolt patterns etc.i did that and as far as i can see everything will match up except the (i think this is what this is called)output shafts have different lenths.they are different lenths below the deck.one comes down like 4&3/4"the other 7&a half.now i put a socket up in the shaft&a bolt?nut is in there.so they do come off,right?so can i hopefully just switch them?any help here would be great.i never did this before but i'm up for the challenge!then if i can get this done i can figure out the what gets wired where.thanks

 
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07-11-08, 03:34 PM   #2  
Posted By: puckett59 everything will match up except the (i think this is what this is called)output shafts have different lenths.they are different lenths below the deck.one comes down like 4&3/4"the other 7&a half.
There's more to changing an engine out than just wheather the mounting holes will match.If I read your post right,what your saying is;the crankshafts are of differant lenths.

if one sticks down 3-3/4" and the other 7-1/2 your pulley's wont line up this being so then NO,they won't enterchange.

You'll need to switch chranks,if you can.Or get another engine with the same lenth cranksaft.

 
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07-11-08, 05:03 PM   #3  
not sure if thats the crankshaft.what im talking about is what i thought hooked onto the crankshaft.is it called a pully.its where you put the belts on.1 for drivebelt the other below it belt to turn the bades

 
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07-11-08, 05:07 PM   #4  
reread your post.can't see the crankshaft.pulley still on both engines.the measurements i gave were for i guess the pulleys.how do you take the pulleys off?then i could see if i could change 1 pulley with the other,right?thanks

 
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07-11-08, 05:52 PM   #5  
You'll have to remove the pulleys with a puller first, Then check the crank length & diameter as different units use different pulley types, but inside they may be the same,, Roger

 
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07-11-08, 08:38 PM   #6  
Both engines should have the same bolt pattern and crankshaft dimensions. You'll need to use a 5/8" socket to remove the bolt up in the hole in the pulleys to get them off.


"Who is John Galt?" - Ayn Rand (Atlas Shrugged)

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07-12-08, 01:38 PM   #7  
thanks for info...question,is the bolt a regular bolt or left handed bolt?

 
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07-12-08, 11:29 PM   #8  
Regular right hand threads.


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07-13-08, 06:48 AM   #9  
thank you...wish me luck!

 
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