Recoil kickback not flywheel key on 4hp Briggs

[Ocean909]

Hello all..longtime lurker first time poster.

I have an old Briggs Quattro 4hp L-head that is ripping the recoil cord out of my hand. This mower had its blade come off at speed before it was stowed for some years. I expected a sheared flywheel key. Key Looks perfect. I checked to see if the valves moved at TDC and they are tight.

The mower will start and runs if I use a drill on the flywheel nut to start it but can't get it to go manually. Any thoughts on what else it could be?

Numbers are 10A902-2252-E1

Thanks to all.

 

[StarTech]

Camshaft ACR damaged most likely. Even the plastic cam assembly could have parts that slipped.


If I remember correctly I had to replace several these camshafts because the ACR gotten mangled and the engines had severe kickback on hand starting. But I have seen any in the last 5 years mainly because none engines come in the shop now due the customers changing what they use.

 

[ILENGINE]

You said the blade came off, has the blade been reinstalled. The blade acts like a flywheel, so if no blade it will cause kickback.

 

[slomo]

Agree with ILengine here. Need a blade and recheck the flywheel key.

 

[Ocean909]

Thanks for the replies folks. There is no blade installed so I'll try that next. Before I pull the sump and check the compression release as StarTech suggested, is there anything else that comes to mind? I truly appreciate the time taken to answer this post.

 

[slomo]

Think you will find, as ILENGINE said, you need a blade on her. That is the main reason you are getting your shoulder ripped out LOL. Torque the blade back on to factory specs. Should be golden.

 

[Tinkerer200]

Yeah, you need a blade. Brings to mind many years ago BIL brought his mower with similar engine. I pulled the flywheel and I could see just a mark on the key. I said there is your problem. He gave my that "You stupid idiot" look snearing. I replaced the key, all was well and he had a different look on his face.

Walt Conner

 

[Ocean909]

Finally got my hand on a blade and it did the trick. Thanks to all who replied.