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Why does my 21HP Briggs and Stratton engine bend exhaust valve push rods?

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They don't unless there has been work done and the head/s have been assembled incorrectly
check that the correct rocker is in the right place and that there is tappet clearance
check that the correct push rod is in the right place

Posted on Apr 21, 2015

Testimonial: "I discovered that the exhaust valve guide worked it's way up toward the rocker assembly, limiting the travel downward of the rocker, thus bending the rod. I staked the exhaust valve guide into both heads after pressing them back into their proper position. The engine runs fine for now."

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  • Bill Boyd Apr 22, 2015

    thank you for your explanation of the fault and how you fixed it. It is unusual for guides to come loose normally, and it started me asking the questions of why it should happen. basically I could think of only 3 explanations. one is poor lubrication allowing the valve stem to bind in the guide, two over heating of the head and engine ( possible mixture or spark timing and three faulty manufacture. It is not unusual when DIY's try to replace guides at home and get the dimension wrong but in a engine from new is most unusual. Thanks for the input as it helps increase my knowledge base

  • Eugene Rounds Apr 22, 2015

    Then this would have been an OHV engine and yes the valve guides do work loose on these sometimes. On the Briggs OHV Briggs don't even offer valve guides for these heads. I wish they did as it is need for rebuilds sometimes and only current option is a new expensive head.

  • Bill Boyd Apr 22, 2015

    talk with an engine re-builder engineering shop as guides come in all shapes and sizes. there is every possibility that there are guides that will fit or can be turned to fit the head. it may be worth while looking into


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What are the torques on a 22hp ohv briggs and stratton head and also push rods

VERIFY your engine model numbers
Briggs & Stratton Intek V-Twin
Engine Model Numbers 407777 and 44P777
Cylinders 2 (Dual cylinder)

ITEM N m (Newton metres) lb-in Spark Plug Torque 20 180 Back Plate (to cylinder) 11 100 Blower Housing Screws 9 80 Breather Screws 6 55 Carburetor to Manifold 7 65 Cylinder Head Bolts 25 220 Cylinder Shield 7 65 Crankcase Cover 23 200 Engine Mounting Bolts 48 35 lb-ft Electric Clutch Mounting Bolt 75 55 lb-ft Exhaust Manifold 16 140 Fan Retainer Bolts 16 140 Flywheel Nut 203 150 lb-ft Armature Mounting Screws 3 25 Intake Manifold Bolts 9 80 Rocker Arm Adjustment Lock Nut 7 62 Rocker Support Screws 11.3 100 Valve Cover Cap Screws 11 100 Carburetor to Intake 7 65 Valve Clearance (Cold) 0.10-0.13 mm (0.004-0.005 in)
WARNING: Uneven tightening will warp the head. Tighten Cylinder Head Bolts down evenly by hand. Then using torque wrench tighten in sequence, in 9 N m (80 lb-in) increments to 25 N m (220 lb-in).
Intake valve push rods are aluminum.
Exhaust valve push rods are steel.
DO NOT interchange push rods.

Removal and Re-installation sequence for bolt removal and tightening.





Mar 21, 2015 | Garden

1 Answer

Craftsman 16 HP Electric start 41" mower - on a overhead valve briggs and stratton two stroke engine the hollow push rod bent. We pulled the head and everything seemed in working order. The replacement...

On any pushrod engine you have to make sure that the timing is correct or nearly correct when first firing it up, if you had the cam in the wrong position the pushrod had no place to go when the cam lobe came around=bend push rod.

Sep 24, 2010 | Garden

1 Answer

Need valve settings for 14.5 ohv briggs


watch inlet valve open and close fully
set engine @ 1/4 past tdc on power stroke
sett inlet @ 0.003 thou and exhaust @ 0.005 thou

inlet valve is the one cloest to the muffler and ex is the other one

inlet has alloy push rod and ex has steel push rod

plug type is rc12yc

cheers hope it helps

here is web site

Aug 01, 2010 | Briggs & Stratton Garden

2 Answers

B&S V-Twin 24 hp has done 150 hrs and has now started to backfire a lot. Engine starts well

Take off the valve covers and check the valve lash. @ tdc on compression stroke then same on exhaust stroke the clearance between the rocker and valve should only be .001 to.003 in.Carefully adjust to this tolerance,may cure your problem. seems this is a common problem.

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Briggs motor bent one push rod

This is a vary commom problem with an Intek engine, I have a similar 21HP engine with similar issue. The valve is sticking in the valve guide, the valve guide usually slides in or out. If out, the guide can jamb against the keepers and not allow full valve opening, thus bending the rod. Fix the loose guide and tight valve before you put in another rod, or you will soon be putting more rods in. I think B&S should help everyone on this one. If the guide goes in, it can cause the valve not to close fully and cause a no run condition.

Sep 14, 2009 | Briggs & Stratton Briggs Stratton Intek V...

2 Answers

Briggs&straton model28n707 type0173-01 won't start

Ours did the same thing. It turned out to be a bent push rod. The intake valve keeps seizing after it's shut off. We free the valve, straighten the push rod and it will run till we shut off. Then same thing. Valve seizes and bends the push rod. We have a call into Sears to see if warranty will fix.....

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