Flywheel tightens to 65 Ft. Lbs. .008" to .012" on air gap.

Walt Conner

Walt,any thoughts on the above condition that would be shearing the flywheel keys?

"1/2 in. socket wrench" ??? (long enough to get good leverage??) 65 foot pounds is quite abit. Get a cheater bar or move up to 1/2" breaker bar if you don't have access to a torque wrench. If it spins over good with the starter IMO you arn't getting the flywheel bolt tight enough. You may have to hold the crank from the pulley bolt while cranking on the flywheel nut.

"Walt,any thoughts on the above condition that would be shearing the flywheel keys?"

Improper torque setting.

Walt Conner

Thanks guys, I had already returned home when I started this post so next trip to work on it I will have my torque wrench. I should have been more clear, I was using a 1/2 inch drive socket wrench. Will let you know of the outcome.

I found the saame problem recently with a B&S engine on a Sears tractor. It had sheared the fly key, so, when i took it apart--there was the problem!! Somebody else had evidently lost the Delville washer, and just put in a flat washer, which didn't do much except allow the flywheel to loosen and shear the key!

Bellville washer...place it so the concave side (dish) faces the flywheel and the convex side(dome) faces the nut.

Mownie: for years, i have been calling that domed washer a "Belleville". I recently hd to go to the mower shop to buy a new one. They call it a "Delleville"!
By any other name, its still a domed locking device, used in place of a regular lock washer.
I would suppose that it has several ways of spelling and naming it, in different parts of the land. HMMM??

rustj, I have never seen/heard them referred to as Delville (and I thought you just inadvertently had hit the "D" key instead of "B"). I did a search for "Delville washer" (using various spellings) and was never directed to anything regarding "conical tension" devices. The name Delville came up often but never in the context of fasteners. Using "Belleville washers", however, will get you a bunch of "hits" in the subject of fasters. I include a link to just one site. As to the term "Delleville washer" at your mower shop, it would not be the first case of "misunderstanding a spoken word" (their hearing, not yours) or even a "typo" being repeated down the line until it seems to become something it is not.

Here is a link that might be useful: Oh Bellevedere, come heah boy.

Want to say thanks for the replies on this subject. I torqued the the crank bolt and realized I was nowhere near 65 ft. lbs. by trying to guess by feel. It Runs fine.

Hi I have a 9hp B&S vertical shaft model 28B702 engine. I recently replaced the flywheel with a used geared one so I could add a starter to it. I sheared a couple of flywheel keys until I noted a torque of 80 ft. lbs was needed, I did that but today while starting it backfired a couple of times and now will not start. So I need to pull the flywheel and change the key again I guess. I also did not pay attention to the Delieve washer but noted someone mention it had to be dish side down. I think 80 ft. lbs should be okay, but I think I saw somewhere it my be up to 100 ft. lbs torque. Thats quite a bit of torque I don't think I can handle that as I have shoulder issues. I"ll try the 80-85 ft. lbs first and hopefully it stays torqued. Could it be that the used flywheel need lapping so it fits tighter to the shaft? I cleaned the shaft and flywheel hole with some brake cleaner so it should grab better. Thanks for any suggestions

Hugo 138

to james sasaki

for the 28B702 engine series, the specified flywheel torque is 100 ft lbs. This information is from the single cylinder service manual and also from the Briggs power portal.