Briggs OHV Valve AdjustmentArticle by mark Trotta

Through mechanically use and wear, tiny gas engines require valve adjustment from time come time.If her engine is not beginning or to run poorly, it might be the valves space not totally opening and also closing.

You are watching: Briggs and stratton 19.5 hp valve clearance


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To save your engine to run it"s best, valve clearance have to be checked and readjusted as component of periodic maintenance.The procedure because that adjusting valves ~ above Briggs OHV motors is usually the same for every models.

NOTE: Lawn mowers, lawn tractors, and also pressure washers all run at a short RPM level.Unless your engine is powering a gyeongju kart, over there is no need to change valves if they"re only out the spec by .001" or .002".

This short article describes how to adjust valves ~ above two different Briggs & Stratton motors.The first is a Craftsman push washer through a 7-hp motor, the second is a man Deere lawn tractor v a 19.5 hp motor.

Why Valve Clearance Is Important

If a valve has actually too lot clearance, that doesn"t totally open.This robs the engine of power.


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If a valve doesn"t have sufficient clearance, the doesn"t completely close. This enables some compression come escape through one or both valves.Aside from losing power, the influenced valve(s) may become overheated.

Valve Clearance Specs

Valve lash, or the space between the valve and rocker arm, different slightly indigenous engine to engine, so inspect the specs top top yours.Valve clearance specs can be found in one owners hands-on or shop manual. You can also find the specs online, however will require to know the engine version number.

NOTE: constantly check and change valves once engine is cold.

Set Up her Workspace

Rather 보다 kneel and also bend down while working, I prefer to lug the work up come a much more comfortable height.The less contorting you have to do, the much easier the organization will go.


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Briggs-powered Craftsman push washer (7 horsepower)

Tools Needed


3/8" socket (1/4" drive ratchet preferred)Spark plug socket (3/8" journey ratchet preferred)Feeler Gauge3/16" Allen key5/8" Open end wrenchLong screwdriver (optional)
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NOTE: You execute not have to drainpipe the engine oil prior to taking the valve covering off.

Remove Valve Cover

Here"s another advantage to propping increase the work-related to a far better working angle.The valve cover comes turn off with 4 3/8" headed bolts.The first time i took a Briggs OHV valve covering off, I only saw the 2 side bolts, and also after removed those two, proceeded to try prying off the still-bolted-on cover!


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Looking inside the valve cover provides you a good indication as to whether the engine oil was adjusted regularly.On this motor, i was pleased to see just how clean the rocker arms, valve springs and also valves were.

Remove Spark Plug

Removing the spark plug reduce engine compression, making that much much easier to traction the start rope to move the piston and also valves right into position.With the valve cover off and the spark plug removed, you deserve to pull the start rope and also watch the valves open and also close.

How To inspect Valve Clearance

There room two famous methods for checking valve clearances.The encourage procedure from most company manuals is an approach #1, whereby a driver is provided to gauge the piston"s variety of motion.

Method #1

Insert a narrow screwdriver right into the spark plug hole and also touch the piston. Traction the start rope and move the piston/valves. The driver goes up and also down accordingly. When the screwdriver sticks out the most, the piston is at the optimal of it"s travel. This is recognized as peak dead center, or TDC.

Move previous TDC until the piston has actually moved down 1/4".You will now have slack top top both entry (upper) and also exhaust (lower) rocker arms.


Check the valve clearances one at a time by put a feeler gauge between the each valve and rocker arm.Adjust as necessary (see "How To readjust Valve Clearance" below).

Method #2

For this method, friend don"t require to uncover piston TDC, but it will certainly take second step.You will begin with the intake next first, followed by the exhaust side.

NOTE: Some motors will have the intake rocker eight on the top.Some electric motors will have the exhaust rocker eight on the top.You can usually monitor the path of the input manifold (or the muffler pipe) to determine which is which.

Intake top top Top, Exhaust ~ above Bottom

Pull the start rope slowly.When the bottom rocker pushes the exhaust valve in, the top (intake) valve will have slack.You can now examine the intake valve clearance and change if needed.


After the intake side is done, traction the start rope slowly, and watch because that the peak rocker to push the input valve in.The exhaust valve will certainly now have actually slack.Check clearance and adjust if needed.

How To adjust Valve Clearance

Loosen the lock seed on optimal of the rocker arm by transforming it counterclockwise. Do a mental note regarding how tight it was.This will help when re-tightening.


Set your feeler gauge come the recommended setup for your engine.Remember the intake and also exhaust settings might be different.

Insert the feeler gauge between the rocker arm and the valve and check the clearance.

If the void is as well wide, take it an Allen vital to revolve the center adjusting screw clockwise in the rocker arm.You will certainly only have to turn the a very tiny amount.When the space is correct, the feeler gauge have to fit snug, however still maybe to relocate in and also out there is no binding.

Once the adjustment is completed, organize the Allen vital in place and tighten the rocker nut with an open-end wrench.

Remember when you loosened the lock nut, exactly how tight that was?The proper torque value is around 45 inch-pounds.Hold the rocker nut through a wrench and tighten the rocker sphere set-screw. Be mindful not come over-tighten it.


Using the same procedures, examine and change the exhaust valve.

NOTE: On some Briggs engines, the nut and also set-screw space positioned over the press rod ends.

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The valve clearance specs on my Craftsman pressure washer were:

Intake Valve .004" to .006"

Exhaust Valve .004" to .008"

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When done, double-check the settings before re-installing the rocker cover and spark plug.

Rocker covering Gasket

Inspect the old rocker cover gasket.If it"s not ripped or torn, re-use it.If it"s damaged in any kind of way, you can either replace it with a brand-new one (easier) or usage RTV gasket an equipment (messier).Be mindful not come over-tighten the bolts (a usual mistake).


Shop:Briggs & Stratton 691890 Rocker sheathe Gasket


After the engine is ago together, start it up and let it run for 10 minutes or so.This will burn off any residual grease and also oil. Then inspect the rocker covering bolts and re-tighten together needed.

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Adjust Valves top top Briggs Intek OHV

Adjusting valves on my Briggs-powered lawn tractor was comparable to the pressure washer.A minor difference was that the top valve to be exhaust, no intake favor the 7-hp motor.


Remove the bolts hold on the rocker cover.Remember the valve clearances space checked and adjusted while the engine is cold.


Since there"s no begin rope to traction on this lawn tractor, here"s one alternate means to move the valves.With the spark plug removed, seize the top of the flywheel screen and you deserve to turn the motor end by hand.


Exhaust top top Top, input On Bottom

When the bottom rocker pushes the intake valve in, the optimal (exhaust) valve will have slack.You deserve to now inspect exhaust valve clearance v a feeler gauge.

If not within spec, loosen/adjust rocker seed to acquire the wanted clearance, then re-tighten.Hold rocker nut and tighten the rocker ball set-screw come the proper torque worth (about 45 inch-pounds).

After the exhaust next is done, revolve the engine slowly, and also watch because that the optimal rocker to push the exhaust valve in.The entry valve will certainly now have actually slack.Using a feeler gauge, check valve lash.

If not within spec, loosen/adjust rocker nut to obtain the preferred clearance.Hold rocker nut and also tighten the rocker ball set-screw to the ideal torque value (about 45 inch-pounds).

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The valve clearance specs top top my john Deere LA110 lawn tractor were:

Intake Valve .003" to .005"

Exhaust Valve .005" to .007"

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After i was done with the valve adjustment, i double-checked my settings, climate re-installed the rocker cover through a brand-new gasket (Briggs # 272475s).


Shop:Briggs & Stratton Rocker sheathe Gasket

I also installed a new spark plug (Champion RC12YC) v .030 gap.