Riding Mower

Repair guides and support for riding, or ride-on, mowers, also known as lawn tractors, of all types used in tending large tracts of land.

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Adjusting valves on a 17 hp briggs & stratton motor

I have a John Deere riding lawn mower. How do u adjust the valves on the motor & what size gauge should i use

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Which engine model is it? Is it a B&S 17hp OHV motor?

by oldturkey03

I think this #is right model#711777 or it's 11777

by sami

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gump 01, here is a general idea about some of the B&S engines. O could probably provide you with a bit more in depth information, if I would know which engine model you have. :" Adjust Valve Clearance

All Models - Except Vertical Models 110000, 120000 Early Production

NOTE: Check valve clearance while the engine is cold.

1. Turn crankshaft counterclockwise until piston is at top dead center on the compression stroke. This prevents the compression release from holding the valves open.

2. Insert a narrow screwdriver or rod into the spark plug hole as a gauge, then slowly turn crankshaft counterclockwise until the piston has moved down the bore by 1/4” (6mm).

3. Using a feeler gauge (A, Figure 41), adjust rocker nut to obtain the clearance as listed on the bottom o this answer.

4. Hold rocker nut and tighten the rocker ball setscrew (B) to the torque valve of 45 lb-in. (5 Nm).

5. Check clearance again and re-adjust, if necessary.

6. Repeat for other valve.

NOTE: On some models, the nut and setscrew are positioned above the push rod ends.

Block Image

Vertical Models 110000, 120000 Early Production

1. Using a feeler gauge (A, Figure 42) adjust the locking hex nut (B) to obtain the

correct clearance as listed on the bottom of this answer.

2. Repeat for other valve.

Block Image

- OR -

1. Loosen jam nut (A, Figure 43) at base of rocker arm stud. Then, using a feeler gauge (B), turn rocker arm screw (C) to obtain the correct clearance as listed on the bottom of this answer.

2. Hold the screw and tighten the jam nut to value 45 lb-in. (5 Nm).

3. Check clearance again and re-adjust, if necessary.

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MODEL 110000 HORIZONTAL SERIES

Valve Clearance – Intake .004 - .006 in. (.10 - .15 mm)

Valve Clearance – Exhaust .009 - .011 in. (.23 - .28 mm)

MODEL 120000 HORIZONTAL SERIES

Valve Clearance – Intake .004 - .006 in. (.10 - .15 mm)

Valve Clearance – Exhaust .009 - .011 in. (.23 - .28 mm)

MODEL 150000 HORIZONTAL SERIES

Valve Clearance – Intake .004 - .006 in. (.10 - .15 mm)

Valve Clearance – Exhaust .009 - .011 in. (.23 - .28 mm)

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Normal engine rotation is clockwise looking at flywheel side.

by ettinjon

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This information is wrong!! Top valve on this engine is EXHAUST! Bottom is intake

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Additional info:

I have a 17.5 HP Model 31C707.

Valve Clearance – Intake .003 - .005 in.

Valve Clearance – Exhaust .005 - .007 in.

I prefer to not stick anything metallic down the spark plug hole. A disposable chopstick works fine and makes it easy to mark at TDC, then put a second mark 1/4 inch farther out.

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What is the torque spec for the valve cover bolts?

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gump01 will be eternally grateful.

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