Pull Start Kickback

[dennis]

I have a Briggs & Stratton Extended Life Series IC-Intek (10.5HP) engine on my log splitter. Engine model # 215802, type 0114-E1, code 050726 ZA.

I have used it for 12 years, change oil regularly, adjust the valves almost annually, and change air filter and fuel filter as needed, It has always started easily and ran great. Now, it has started to kickback hard when I start it cold. Once started and warmed up, it runs well, and if shut down, starts easlily with no kickback. I have not checked the flywheel key yet, but because it runs so well and starts easily when warm, I don't think that is the problem. I adjust the valves to specs, 1/4" past TDC. Before I check the flywheel key, and re-adjust valves, has anyone had this experience with this engine? Any other suggestions would be appreciated. I did put an inline shut off valve between the gas tank and fuel filter a couple of years ago.

[KE4AVB]

I would think the 793880 camshaft has failed. Check for your decompression bump on the valve. Should be on the exhaust on this one. The 793880 are prone for the ACR to break.

[Skywatcher]

Hi Dennis

The other valve related problems I've run into on this series of engine are the valve adjusters breaking and the rocker studs coming loose. The old style adjusters were made of pressed powdered metal and the end with the locking screw tends to break off. The new adjusters are way more beefy and appear to be machined steel as opposed to powdered metal. The other problem is the studs that actually hold the rockers onto the head can come loose. I have a ¼" drive 10mm crowfoot wrench that comes in real handy for tightening these studs. If I have to tighten the same stud on the same engine more than once, it comes out, gets cleaned and reinstalled with Loctite® high strength thread locker. Between this and what KE4 says, you should get this one figured. All the best,

Sky

[dennis]

Thanks for the information, Skywatcher.

[dennis]

Besides a broken ACR, could a worn lobe on the camshaft cause kickback? If so, could narrowing the clearance when adjusting the valves compensate for the wear, at least temporarily?

[KE4AVB]

I haven't seen any worn lobes on these yet beside the ARC actually stick out when in operation until up to idle speed. But think about it, Do you want to take a chance on broken metal just laying in the engine that could be bump up into the gear train? Easy enough to check for if broken as the decompression bump won't be there.

[Skywatcher]

Hi Again Dennis

A worn cam lobe will not affect the ACR action, the affected valve just won't fully open. Remove the rocker cover and the spark plug then check for loose or damaged valve hardware. Check the valve clearances as per normal procedure. Now, slowly rotate the engine in normal running direction and carefully watch the valves. The exhaust valve should open and close. As the exhaust valve is closing the intake valve should start to open, this is TDC exhaust stroke. Rotate the engine 180º, the intake valve should open and close, now you're at BDC intake stroke. Rotate the engine another 180º and watch both valves very closely. One of the valves (probably exhaust) should just start to open, then close again before you hit TDC compression stroke. This is the valve dumping some compression for ease of starting. If the valve does not open slightly, KE4 has hit the nail on the head, your ACR is stuck or broken.

You indicate the engine starts properly once warm, this would indicate the ACR is sticking and not broken yet. Either way, I would recommend replacing the camshaft before it does break and cause further problems. All the best,

Sky

[dennis]

Once again, thank guys for the helpful information. A piece of loose metal could really mess things up. I will check for the exhaust valve bump, and to be safe, put a new camshaft in this winter.

[hanz63]

You got it. That little ACR can do lots of damage. This year I've had a broken block (above the cam) , a broken drive gear on the crank and one that the guy continued to run to the degree that the little spring from the ACR found its way through the screen and into the pump enough to ruin the sump and pump.

[dennis]

Finally got back to the log splitter. Checked for the decompression bump on both valves. None. I guess I will have to replace camshaft. KE4AVB...You said that camshaft 793880 are prone for the ACR to break. Do you know of another camshaft for this engine that would work?