Briggs OHV single cylinder?

[Arkie]

Cannot get a compression release on the following engine by adjusting valve lash at .003 inches.

331877 1371 B1
code 090925ZD

Air cowling has following into
Briggs Platinum, 540cc, 21 gross hp, XRD

I'm adjusting by turning the flywheel CCW (looking down on top) to 1/4 inch of the piston past TDC. (per the Briggs service manual for a 330000)
If valves are adjusted to .003 it has compression lock-up.

I can set the valves to .0015 and get a release but the engine is not smooth when it starts and gets more unstable as the engine warms up. Cannot get a comp release at .0025.

I cannot see any rocker arm bump on either the intake or exhaust valve as I slowly turn the engine in either direction.
Should I see a rocker arm bump when adjusted at .003?
Is the comp release on the intake on this engine?
How do I check to see if this is a camshaft release failure? The rockers, springs and adjusters appear ok.

The engine came to me with this issue and I found both valves set at very minimum of .001 area and someone been adjusting before because the valve cover only had permatex gasket maker.

[KE4AVB]

The ACR is on the intake valve (closest to PTO end). If it don't bump at .003 then the camshaft has failed. Quite common on this series. And you need to replace because of all the broken parts inside the engine when they. Just note you might even need an oil slinger/governor. Of course sump gasket, oil seal, and if present oil pump o ring. These darn camshafts are bad design that Briggs has never tried to fix. They just makes too much off selling new camshafts to care.

And I only use RTV on these engine which what Briggs put a service bulletin out for. Just remember when applying RTV there must be no oil present, use a surface prep spray (preferred but not necessary if want the RTV to leak later), Install the rocker cover with screw finger tight overnight (don't start the engine), and then torque down to 65 in/lbs. Oil getting on the RTV before it is cured will cause it not to setup. Following this procedure I seldom ever have one to before I need to remove it again. BTW a heavy hammer and a one by four is how you shear the rocker cover off. Otherwise it is a pain to get those covers off. Of course you got to clean up the RTV.

And whatever you do don't buy one those aftermarket camshaft either. The ones I tried didn't fit right and I done had one to fail withing 6 months. On that one the ACR pin wore slap in two. Very soft metal.

[Arkie]

Very good info KE4AVB. Very good info about the Briggs common ACR issue on this engine and not to use the China clone kit.

Also good info about the sump gasket area leaking after awhile.. I've had experience with that area and the gaskets and gasket makers and too let the RTV cure before exposing it too oil. (good info, thanks)
I have some Yamaha bond that seems to work good.


Question?

This Briggs service manual says to turn the engine CCW 1/4 inch past TDC. (opposite the normal running direction)

Why turn the engine the OPPOSITE direction which it normally turns.

Using common sense logic I would think that the valves would be adjusted just past the ACR which would require CW rotation when looking at the flywheel????

Reason I ask about watching for a bump on the intake is I have a engine like this, oil pump and all for PARTS in storage, a non-runner. Wondering if I could check it by watching for a slight bump on the intake valve so as to get an idea if it's cam might be good instead of pulling the sump and cam to inspect.????????

[KE4AVB]

I tried that method of adjusting but always do in the same direction as normal engine rotation but I just keep falling back to adjusting one at a time. Just easier for me to do to old way. I reckon that is what I get for being an old fart.

[Arkie]

I tried that method of adjusting but always do in the same direction as normal engine rotation but I just keep falling back to adjusting one at a time. Just easier for me to do to old way. I reckon that is what I get for being an old fart.

What I'm referring to is on pg 21 of the Briggs single cyclinder OHV service manual. (How to adjust valve clearance, right hand column)
If 1/4 inch past TDC going CCW (backwards this would place the lifter on the ACR. (instead of after the ACR.

Wondering if this is a mis-print in the Briggs manual. (surely Briggs would not put out any wrong info in print)

[KE4AVB]

I know what the manual notes but my online in the downloads makes a note that it appears to be incorrect as it just don't make sense to have the possible ACR interfere. The manual is assuming that the tappet resets the ACR when the valve clearances are excessive which OHV are prone to have before adjustment.

[Arkie]

I'll put that red note in my printed manual.

I double checked it again this morning and it has no ACR at all. I have to trial and error (mostly error) and very carefully get the intake lash at about zero to get a release and run.
The intake valve is going to probably burn if the engine was run very much at that setting.

I check my spare parts engine in week or two and see if I can see a bump release on it. It has the head off therefore I cannot just feel for a lockup and no ACR.

Appears Briggs should have been forced to do a recall on these type design failures.

[bgsengine]

I'll put that red note in my printed manual.



I check my spare parts engine in week or two and see if I can see a bump release on it. It has the head off therefore I cannot just feel for a lockup and no ACR.

(

Easy- long screwdriver, or just a piece of 1/4 inch dowel rod down the pushrod galley on the tappet, you can feel for the bump as you observe piston, no?

[Arkie]

I'll put that red note in my printed manual.



I check my spare parts engine in week or two and see if I can see a bump release on it. It has the head off therefore I cannot just feel for a lockup and no ACR.

(

Easy- long screwdriver, or just a piece of 1/4 inch dowel rod down the pushrod galley on the tappet, you can feel for the bump as you observe piston, no?

I'll try that.

Thanks

[KE4AVB]

Ah I see where we were going wrong our thinking. It all about the point of view. It is CW when viewed from flywheel side but CCW when viewed from the PTO end. Now does this makes sense? So I got to clarify my manual notes.