UPDATE. Turned flywheel by hand a few times. Very stiff. Part of turn is easier, then gets hard. On part of turn, hear a funny little noise from inside. Could be air escaping???

Tried to start a few times. Same as before. Starter engages. Nothing happens. Then after a second or two, the flywheel turns. Sometimes it only make a half-turn or so, then stops; if maintain key, it might turn again. Twice, flywheel turned 4-5 times; tried to quickly adjust throttle to fire off but unsuccessful.

Silly question , but you have ensured oil level is full correct ? Second question have you verified fuel filter is not restricted . 3rd question have you checked valve lash recently ? The noise could be normal compression / exhaust cycle .

Thank you ssewalk1. I should have mentioned the oil initially, but yes; the oil level is normal. You can be my straight man for your 2nd question. I do have a very important update...

Well, even though I almost hate to give credit to some of the worst acting possible by a couple of serious ignoramuses (https://www.youtube.com/watch?v=8PEUt_KAcYk) I removed my OHV cover and saw A problem. Whether it is the cause or a symptom is to be determined.

So the 1st thing I noticed were pieces of plastic in the OHV cover. These turned out to be pieces of the plastic "valve rod guide" (my own term) as seen in the 1st photo. The 2nd thing I noticed was that the valve rod was bent.

So the question is, "Can I simply replace these broken parts and cross my fingers, or is this motor shot???"

Appreciate the help and advice.

I pulled the other rod to inspect. It was not bent.

Thanks

Intake valve correct Aluminium ? Must determine what condition the valve is in . Also what caused the damage broken valve spring or rocker . The valve lash apparently was not adequate . On some Briggs adjustment every 100 hrs minimum .Worse case scenario you may want to remove the head to inspect the valve face and piston dome for damage .

So Tom your initial causation is the guide wore through the wall of the pushrod causing it to bend ? Valve train lash was not improper ?

Tomplum. Thank you for mentioning the "valve caps." I did 2 round discs in valve cover and valve compartment. They look like little magnets...but they're not magnets. I assume that they go on the end of the rod with spring (valve). Until you mentioned that, I had no idea what they were. When I look at parts page (https://www.jackssmallengines.com/jacks-parts-lookup/part/briggs-stratton/691843?gclid=cjwkcajw_ttxbrbseiwarqxymuogynawcohjcyqv-0j9fu3xbys5qnkgy1dyicty0mh9abqkmlnqixocgxaqavd_bwe) it is apparent that is what they are. Thank you.

Yes on the guide wear. I've seen it several times over the years. The wear probably could be accelerated by loose rocker studs. Or possibly excessive lash. Yesterday I did a head gasket on a 33. That one would have been another candidate for a push rod if it would have run out much longer.. It is a good practice to flip the push rods end for end when doing valve lash for this reason. At least the intake on these.

Yeah with the aluminium rods wear through would not take long and I thought valve lash when the op mentioned the unusual internal engine noise .

OK Guys. Great news.

I received my 2 push rods via Amazon yesterday. Today I (a) replaced my bent intake push rod w/new push rod and (b) replaced the push rod guide [plate] with one stolen off an older, mostly-dead Craftsman mower (since Amazon won't deliver the new push rod guide until tomorrow).

As an aside, I did note that the top (exhaust) rocker arm stud was loose and had backed out a bit (not sure how much). So when I replaced the push rod guide [plate] I snugged the 2 rocker arm studs in as much as I dared [didn't want to strip the aluminum hole threads].

My top valve clearance was pretty loose when I first looked at the valves the other day; now I realize probably due to the rocker arm stud backing out. Of course, the fact that the valve caps had fallen off (thanks tomplum) could have accounted for all or most of that slop??

I set both valve clearances to 0.004".

Put it all together and started it up first time!!

So here is my theory as to what happened...

1. The intake plastic push rod guide on the push rod guide [plate] broke. The aluminum push rod now scraped against the edge of the steel push rod guide [plate] until wore thin enough to bend. Of course, if the rod had bent first, it would likely have broken the plastic guide, but the push rod had a very nice, even wall thickness wear all the way around, so I think the former guess is correct.

2. The exhaust rocker arm stud backing out didn't help the motor, but I can't see how that would have caused anything else. Eventually, it would have stopped the motor too.

Thank you ssewalk1 and tomplum for your comments and moral support.

No problem Yard , keep an eye on the valve lash religiously on these Briggs Bud !

Excellent! Though I would go ahead and remove the rocker studs that were loose. Clean them and the threads in the head , blow them dry and lock them with red thread locker. .005" on the exhaust (upper) and .003 intake.

Absolutely on the Loctite for the rocket studs , since they have gone through numerous thermal heat cycles and could loosen again , good follow up Tom !