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

I have Briggs and Stratton 500 cc silver edition 17.5 HP motor on a craftsman Lt 1500 riding mower I need to know the valve torq spechs can someone please tell me them thanks

by jeff grant

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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.

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- 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.

Block Image

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

This info was very helpful. My 17.5 Briggs, was backfiring out carb. While I was mowing the machine bogged down, and started sputtering, backfired and I couldn't get it to start again. I checked spark, fuel, compression, took out plug, turned motor and no ugly noises. While trying to start, it seemed to have to much compression. It would only turn over on intake stroke. I took valve cover off, and the end cap in spring of exhaust valve was sitting in cover and lock nut had back out. I tightened lock nut, put cap on, and adjusted valves to specs. However I eyeballed the 1/4 inch past tdc. Tightened it back up, and still had same issue. To cover off again, and measured the 1/4 past tdc, readjusted valve to spec. Before putting cover back on, I turned it over and it fired right up. I shut it down, put cover on, tightened everything up, and she runs just like new. This info was helpful. If I can do it, anyone can.

by Matt Rice

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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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Should the exhaust vavle have the same amount of travel as the intake vavle?

If so what could be resticting the travel of the exhaust valve.

I ask because the original rocker on the exhaust broke. As well as the new one. The intake valve rocker is so loose it seems like it would almost let the pusb rod fall out. It has more travel than tbe exhaust vavle. Certainly more loose than the specs. But has not been touched.

31c707 model.

Perplexed.........??

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How to set the valves in a Briggs and Stratton riding mower model number31c707

0230.

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i have a 311707 model what is the correct adjustment the valves need to be and what should the rocker nut be torqued to

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I used a pencil for marking TDC and it must have been brittle because a portion broke off in the spark plug hole.

I manually rotated the cylinder but can not see it.

Will I have to disassemble the engine to get this out?

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cvherb

Stick a tube in hole & blow it out. If that don't work, roll it over a few times should should crush it burn & go out exh. Could take cowl off & spin with drill. If that don't work then pull head off. If it is just a little pencle might hold a valve off seat.

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gump01 will be eternally grateful.

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