Briggs and Stratton 31r976-0016-g1

David357

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Recently purchased this engine to replace a Kohler cv15t motor that took a dump few weeks ago on my 04 john deere g15 commerical walk behind mower. Iam needing help to find out what diameter and length of self tapping bolts to use to mount this Briggs and Stratton 31r976-0016-g1 17.5 hp intex engine to mower. The holes are smooth right now with no threads cut. Seen somewhere online that it's a 3/8"-16 x 1 1/4" self tapping bolt needed . Can anyone verify this for me ?

Thanks David in Texas
 

slomo

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I would use a real tap on the threads. Same size as the mounting bolts. Use plenty of cutting oil when cutting threads.

slomo
 

David357

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Okay but what size bolts ?
 

StarTech

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Yes 3/8-16 x 1 to 1.25 long self tapping is what they use.

For tapping aluminum DON"T use cutting oil; instead, use 70% or high rubbing alcohol. Taps can jam using oil when tapping aluminum.
 

David357

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I would use a real tap on the threads. Same size as the mounting bolts. Use plenty of cutting oil when cutting threads.

slomo
Yes 3/8-16 x 1 to 1.25 long self tapping is what they use.

For tapping aluminum DON"T use cutting oil; instead, use 70% or high rubbing alcohol. Taps can jam using oil when tapping aluminum.
Thanks alots
 

slomo

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Yes 3/8-16 x 1 to 1.25 long self tapping is what they use.

For tapping aluminum DON"T use cutting oil; instead, use 70% or high rubbing alcohol. Taps can jam using oil when tapping aluminum.
WD-40 works perfect cutting aluminum threads. Friends dad owns a machine shop. Learned that trick from him. Some metals, best to use certain oils when cutting threads.

slomo
 

StarTech

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Hate to say this but after a few broken taps that had to be cut out with carbide bits I no longer use any oil when tapping aluminum. I have even broken them using Tap Magic tapping oil.

Just use whatever you want as long as you are prepared to cut out a broken tap as tap extractors don't work either once you break one off in aluminum.
 
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