calling all briggs experts

[Mike 0]

Can anyone tell me how to know what size shafts are on briggs vertical motors from model, type and code numbers? I've tried the briggs site with not much luck although I do have the crankshaft numbers. i'm trying to determine if the shafts on 2 different motors are the same before removing them. 12.5 twin crank #393382 12.5 single crank #693653 As always thanks for any help, Mike

[MarksA-C 93]

I think they should be the same, im not positive...

[andrewk 0]

I'd need the type before I could look it up...

[Dark 0]

all lawn tractors have the same out put shaft diameter riders use a different size and engines from power equipment Ie. generators, tillers water slurry pumps and etc.. if the shaft you are trying to use is the same length and width (usually 1" for lawn tractors)you can pretty much bet it will work. Lawn tractors run a standard 1" output shaft that is why you can use Kohler, Briggs and Tuchumsa for re-power and use the same pulleys

[Al 6]

Hi, Some of the Sears tractors use crankshafts that are 1" near the main bearing and 7/8" near the end. These units use a special pulley that is stepped. Before you count on using a Sears engine, determine what crankshaft it has. Briggs has a crankshaft spec book. Mine is not really current and I don't know if it is available on line or not. I do have the latest Kohler crank spec books though. Al Eden

[Mike 0]

Thanks Guys, I am actually committing a bit of blasphemy, I want to put a 12.5 briggs froma simplicity into a bolens. The bolens had this odd 12.5 twin in it, and I have a perfect 12.5 single from a regent with a blown hydro. Just want to make sure it will work before I take them both out. The bolens has an electric pto clutch on the bottom of the engine pulley. The engine numbers are below, thanks again guys! 12.5 twin mod 404707 type 011701 code 86111312 12.5 single mod 289707 type 011301 code9306104D

[Mike 0]

Briggs customer service came thru......... Crankshaft # 393382 is tapped at 7/16-20, has a 1/4" Keyway, is 1" in diameter and 3-11/64" in length. Crankshaft #693653 is tapped at 7/16-20, has a 1/4" Keyway, is 1" in diameter and is 3-5/32" in length. Am I correct in thinking that they will interchange and the 1/64 difference in length shouldn't matter? Thanks, Mike

[Dark 0]

??you havent installed that yet?? gee 1/64th off ....I think your idler pully is probably off at least that much lol

[firefoxz1 1]

These engines have different bolt patterns. Some frames have both patterns drilled in so you maybe OK there. The stack pulley should be OK.

[Mike 0]

Well before I actually switch engines I am going to try and replace the blown valve seat in the 12.5 twin. Just wanted to make sure I have a backup plan. Thanks, Mike