Briggs 17HP Twin Intek - Broken Rods

[darrinster]

Model 407777 0128 e1

Broken/bent rods on the #1 cylinder. The exhaust rod was almost eaten. I pulled it out but something was clamping down on it. Picture of the rods.

Engine does spin with no knock. I tried running it on the one cylinder but it would not fire. Was getting spark. Valve guides have not moved.

I noticed really dark oil sludge in the valve cover. I'm guessing the oil was never changed.

Do you guys think the engine is worth saving? Anything else I should check?

 

[motoman]

You mean push rods? What does "eaten" mean. I think most here would say perform basic checks like compression (even cold) as a start.

 

[darrinster]

You mean push rods? What does "eaten" mean. I think most here would say perform basic checks like compression (even cold) as a start.

Yep push rods. The exhaust push rod almost went down into the engine.

 

[motoman]

I'm winging this cause I don't know exactly what engine you have so I will use my familiarity with Intek. When the pushrod is placed thru the hole and into the block area the Intek has solid mushroom-looking lifers. The lifters have dimples about .080" deep to accept the pushrod end. If you don't feel anything to stop the pushrod from going down into the engine it would seem you either by passed the lifter,or the lifter has broken and is no longer there . Next stopping point would be the cam lobe, but that has a shaped contour without a place for the pushrod to seat unless you happen to be hitting the base circle of the cam ...missing lifter . If only one pushrod has this problem measure where the good pushrod intersects head and compare it to the disappearing one.


Edit. I just noticed the pics. Sorry. Trying to push a bent rod down a straight hole will bind. Your broken one does look like something bit it. My intek had a chewed and broken pushrod. Were both broken pieces topside, i.e. you picked up the 2 pcs loose ? You tried the "good" pushrod in both positions?

 

[John R]

This doesn't answer your question but why is one push rod steel and the other one is aluminum?

Seems they would hold up better if they were both made from steel.

 

[darrinster]

I'm winging this cause I don't know exactly what engine you have so I will use my familiarity with Intek. When the pushrod is placed thru the hole and into the block area the Intek has solid mushroom-looking lifers. The lifters have dimples about .080" deep to accept the pushrod end. If you don't feel anything to stop the pushrod from going down into the engine it would seem you either by passed the lifter,or the lifter has broken and is no longer there . Next stopping point would be the cam lobe, but that has a shaped contour without a place for the pushrod to seat unless you happen to be hitting the base circle of the cam ...missing lifter . If only one pushrod has this problem measure where the good pushrod intersects head and compare it to the disappearing one.


Edit. I just noticed the pics. Sorry. Trying to push a bent rod down a straight hole will bind. Your broken one does look like something bit it. My intek had a chewed and broken pushrod. Were both broken pieces topside, i.e. you picked up the 2 pcs loose ? You tried the "good" pushrod in both positions?

The broken in half push rod was sitting inside the head (luckily). The exhaust push rod was on it's way into the engine, I managed to pull it out.

I will try the good push rods on the side that failed. I'll see if there is compression first.

 

[darrinster]

Bad news. The #2 cylinder piston is not moving.

Guess this will be a parts engine.

 

[BlazNT]

Sorry to hear that.

 

[bertsmobile1]

Split the cases.
The rods can fall in and get munched up in the gears.
Apparently fairly common so I have been told.
So look first. Chances are a little bit of the pushrod is stuck between the cam gear and the crank gear

 

[motoman]

If you search you may find a picture of the chewed up pushrod from my Intek in this forum. The part that went down the flea hole into the digestive track was broken like yours, but also had a lot of nibble marks where the gear was tasting before biting. :laughing: