Outdoor Power Equipment and Small Engines - B&S Flywheel Key Issue
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geogrubb
07-23-08, 02:29 PM
I have an issue with a B&S 128602 0445 E1. The flywheel key has been sheared twice, the first time the guy hit a stump and when he replaced the key I'm sure he didn't torque it down enough, anyway I found it setting in the trash so now have a new treasure. The crank has a chunk busted out as does the flywheel. My question is if I set the new key at the front of the key slot where there has been no pressure on either the crankshaft or flywheel can I put something like locktite on the flywheel and crank surfaces to help hold it in place after I torque it down. Also what is the torque setting for the flywheel nut. Thanks and have a good one. Geo
flopshot
07-23-08, 05:15 PM
if the keyway is blown out forget it. loctite won't help.
rogerflies
07-23-08, 08:22 PM
Just so we'll have all the replies in one thread:
Here's a chart showing the torque on the flywheel nut is 55 foot-pounds;
http://www.small-engines.com/torque.html
For sake of comparison, a typical wheel lugnut is torqued 70-80 foot-pounds.
As far as the damage to the crankshaft and flywheel goes, I doubt it's going to last long regardless what you do. But the worst that can happen is that it'll shift, and the engine will quit.
I'd suggest using JB Weld to fill the voids before reassembling it. Carefully clean the parts with acetone. Install the key on the crank, and fill the void with the properly mixed JBW. You may have to use masking tape to keep the JBW from sagging. Let it cure, and then carefully file the JBW flush to the surrounding contour.
Test fit the flywheel to be sure it'll go on and seat properly.
Fill the void area on the flywheel with JBW, trying not to get any on the undamaged side. Use just a little too much, so it'll force its way into the assembly as it's tightened. Install the flywheel and torque it down. Let it cure for at least 24 hours before running the engine.
If it holds, you won't have to take it apart. If it doesn't hold, it'll be easy to get it apart. A win-win situation. :D
Here's a chart showing the torque on the flywheel nut is 55 foot-pounds;
http://www.small-engines.com/torque.html
For sake of comparison, a typical wheel lugnut is torqued 70-80 foot-pounds.
As far as the damage to the crankshaft and flywheel goes, I doubt it's going to last long regardless what you do. But the worst that can happen is that it'll shift, and the engine will quit.
I'd suggest using JB Weld to fill the voids before reassembling it. Carefully clean the parts with acetone. Install the key on the crank, and fill the void with the properly mixed JBW. You may have to use masking tape to keep the JBW from sagging. Let it cure, and then carefully file the JBW flush to the surrounding contour.
Test fit the flywheel to be sure it'll go on and seat properly.
Fill the void area on the flywheel with JBW, trying not to get any on the undamaged side. Use just a little too much, so it'll force its way into the assembly as it's tightened. Install the flywheel and torque it down. Let it cure for at least 24 hours before running the engine.
If it holds, you won't have to take it apart. If it doesn't hold, it'll be easy to get it apart. A win-win situation. :D
geogrubb
07-23-08, 09:25 PM
After closer inspection I found the flywheel is cracked at the keyway, so it was going to fail no matter what I would do. Thanks and have a good one. Geo