# [SOLVED] Briggs &amp; Stratton 19.5 HP Runs - no power



## rlray42 (Jul 14, 2014)

Over the course of mowing my acre lawn, riding mower slowly lost power to the point it could not drive the blades.

I checked the air filter, put in clean gas, new spark plug & cleaned out the carb bowl.. all for naught.. Engine runs fairly well.. Just no top end speed or no power to speak of..

Any suggestions?

Thanks


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## rlray42 (Jul 14, 2014)

*Re: Briggs & Stratton 19.5 HP Runs - no power*

I posted this to maybe be of help to someone else with the same problem...

I finally pulled the valve cover... (WARNING - Oil will run out)

The stud holding the intake rocker arm had loosened to the point that the intake valve was barely opening if at all.

An easy fix when I finally found the right spot!


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## Basementgeek (Feb 7, 2005)

*Re: Briggs & Stratton 19.5 HP Runs - no power*

Hi and welcome to TSF

If it is overhead valves, have you ever adjusted them ?

BG


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## rlray42 (Jul 14, 2014)

*Re: Briggs & Stratton 19.5 HP Runs - no power*

I have never had the occasion to adjust valves before. There are several places that give you the clearances online. 

In my situation I had to back off the adjusting nut on the rocker arm stud in order to get a wrench on the stud to snug it down.

Since I didn't have a feeler gauge handy, I just tightened the adjustment nut down until there was a little 'play' in the rocker arm when the valve was in the closed position. I would say a little loose was better than too tight. -- ??


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## Basementgeek (Feb 7, 2005)

*Re: Briggs & Stratton 19.5 HP Runs - no power*

You have to have a Feeler gauge to adjust the valves correctly, as you know. Adjusting valves is pretty much of yearly maintenance anymore.

BG


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## rlray42 (Jul 14, 2014)

*Re: Briggs & Stratton 19.5 HP Runs - no power*

Basementgeek - I sure hate to disagree with a moderator but my engine manual says valve clearance adjustment is only required if engine performance declines. That said - the valve clearances for my particular engine are; 
Intake Valve Clearance 0.003 - 0.005 in (0.08 - 0.13 mm)​Exhaust Valve Clearance 0.005 - 0.007 in (0.13 - 0.18 m


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## Basementgeek (Feb 7, 2005)

*Re: Briggs & Stratton 19.5 HP Runs - no power*



rlray42 said:


> Over the course of mowing my acre lawn, riding mower slowly lost power to the point it could not drive the blades.


Hence I said check the valves. Feel free to ignore.

BG


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## SABL (Jul 4, 2008)

*Re: Briggs & Stratton 19.5 HP Runs - no power*

Depending on usage of the equipment, it can be a yearly maintenance task. 

As for being too loose......loose valves will affect the compression release needed for easier cranking. Many people have replaced good starters thinking they were bad when the engine was hard to turn over.


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