Briggs 5 HP flathead with 1 inch crankshaft

#1
I have a 5 H.P. B&S, model #135202 that has a 1 inch crankshaft with a scored bore. For my application I need a 1 inch crank. Am I correct in believing that typical B&S 5 H.P. engines that have a 3/4 inch output shaft are actually 1 inch in the block and turned down after the crank passes through the side cover? Or, putting it another way, can I use my 1" crank by putting it in a B&S 5H.P. block that once had a 3/4 inch output shaft?
 
#2
Im prretty sure the 1 inch drive strarted on the 8hp models not sure if you can switch cranks what about your side cover is it 1 inch almost all briggs 5hp motors have 3/4 shaft are you sure you have a 1 inch shaft on your motor now..:grind:
 
#3
I have a 5 H.P. B&S, model #135202 that has a 1 inch crankshaft with a scored bore. For my application I need a 1 inch crank. Am I correct in believing that typical B&S 5 H.P. engines that have a 3/4 inch output shaft are actually 1 inch in the block and turned down after the crank passes through the side cover? Or, putting it another way, can I use my 1" crank by putting it in a B&S 5H.P. block that once had a 3/4 inch output shaft?
Look up therestorekid on here. Checking back in the archives, there was a discussion on that- the bearings aspect.

Izzy, the 5HP was available (from the archives) with a 1" shaft. For sure the 6 has one, since I'm looking at it right now. :wink:
 
#6
Yes you are all good.. You have it rite... :thumbsup: (on the bushing engines) the output shafts are all 1 inch at the journal, then neck down to whatever.. some like yours are 1 inch all the way out, most neck down to 3/4.. some are 5/8...

One the ball bearing pto engines.. the OLDER ball bearing engines.. like up till the early mid 80's engines are a 3/4 inch crankshaft ALL THE WAY TO THE cam gear.. The ID of the bearing is 3/4..

The later motors, the ones with square air filters, have a 1 inch I/D on the bearing.. As long as YOU DON'T HAVE, a pre 86 ball bearing crank, you could ad a large bearing and sidecover to an existing crank..
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A side cover you can change, the biggest problem would be the FRONT journal in the block.. There are aluminum standard, DU bronze bushing, and ball bearing blocks too.. If you had a ball bearing block, you would ALSO NEED the $90 dollar bearing... But as long as you HAVE the bearing, all the front journals should measure out the same....

Briggs are pretty easy to interchange cranks in.. They are pretty standardized...
 
#7
Restored Kid, thank you for the info. To make it simple this a later model engine and does not have ball bearings. Can I simply install the crank in another block and transfer the side cover that came on the 1 inch output shaft engine and call it a day?
 
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