OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines RE Briggs and Stratton -Sprint Lx-40

Hi Guys,
Putting new set of rings in this motor.Any ideas how to screw off the cutting base from crankshaft.Is it left or right hand thread?
First time i have attempted this.
Modelno 10C902.
Type.2032E1
Code.98072155
Thanks
John

John, I've never personally seen or even heard about a mower with a screw-on blade plate. The blade plate is normally held by a boss that is pressed onto the crankshaft. Either the boss has tapped holes to retain the blade plate, or there is a tapped hole in the end of the crankshaft and a set screw holds the blade plate against the boss. All threads are right hand.

If you have already removed the blade plate and are now trying to remove the boss from the crankshaft so that you can take off the timing cover (oil sump, crankcase cover, choose your favourite name for it), in most cases the boss is a moderate press fit on a parallel part of the crankshaft, and you remove it with a puller after dowsing it in penetrating fluid for a day or so. In a few cases (Victa 2 stroke for instance) the crankshaft is tapered and you use a different technique to remove the boss.

If you post a picture of the parts you want to dismantle, we can probably be of more help, but it sounds like a normal Briggs & Stratton, that is pressed on and can be pulled off with a gear puller provided you soak some penetrating fluid into it ahead of time.

Thanks Grumpy,
Thanks for the advice.Inow can see what you are talking about.
For some reason can not uploard pic,s to this site. Will try again.
Regards
John.

Hi All,
Still having trouble removing Boss from this crank.
Is there a special puller i shoud be useing.
I have a three jaw reversible gear puller but it does not line up square on the boss.
Any ideas
regards
John

Looks like a masport/morrison boss on the end of the crank there, I would try gently heating the boss to try and get it to release, not too much heat though as you can destroy the bottom crank seal.

John, it would help if you could post the photo in its natural 186k format - the posted one is only 8k, and doesn't show much.

It appears it is a crossbar style boss, and would require a 2 arm puller, not a 3 arm. Usually you get both center parts with the puller, so you can assemble it with either two or three arms.

It also appears you may have a thread in the center of the crankshaft. If so you should put a bolt in it for the puller screw to bear on so the thread doesn't get ruined. The bolt needs to be long enough to allow the boss to come off the shaft for some distance before the boss hits the bolt head.

At the end of the day the thing you want to avoid most is damaging the thread up inside the crank.
Get a suitable 3/8unf bolt, something longer with a bit of shank on it. Screw that up in the hole so it has plenty of threads up in the crank but a good bit of the bolt poking out through the blade boss.
Get a nut the same size hex as the head of the 3/8 bolt for the nose of the puller shaft to go in, a small bit of grease or oil, your going to trash the nut. Hang a spanner on the bolt in the crank. When setting up the puller slide the spanner over the bolthead so it holds the nut as well. Spanner will do two things, hold the nut central on the bolt head and will stop the point on the puller shaft walking around on the bolt head. When you are winding the puller the spanner will hit one of the arms and that will stop the bolt screwing into the crank as you wind.
Then i stick a tyre lever down through the arms of the puller onto the body of the mower and start winding. It will either move or it wont.


Probably best to cut it off and buy a new one. I have had no luck getting them off in one bit, if you use a 2 leg puller and bolt you end up bending the plate anyway, it cracks it at the boss making it unsafe. I think they are $25-30 new, best i can work out from the pic its just a standard masport one.

Use a small grinder and cut in toward the keyway. Use a new key. You might have to cut both sides. Sit the shaft/motor on an anvil and try splitting the grinder cut open with a cold chisel.
Take care that you do not bend the shaft.



Cheers, Bob.