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Stuck exhaust valve


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#1 dadmotown OFFLINE  

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Posted January 20, 2011 - 05:56 PM

I have a Briggs 7.25hp engine in my B-1 Allis. The exhaust valve is stuck and what is the best way to free it. I have the head off right now. Thanks.

#2 caseguy OFFLINE  

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Posted January 20, 2011 - 06:31 PM

It may sound a little violent, But you'll want to use the spray lubricant of your choice (Aerokroil, P.B. Blaster, WD40, etc...) and lube up the valve stem liberally. Make sure that the cam lobe for the exhaust valve is 180 degrees away from the valve stem (i.e. a gap between the lobe and the stem), then use the smallest hammer you have, a brass one is really nice because it wont mar the valve head, and tap lightly until it begins to move. Once it seats, you should be able to rotate he cam lobe back up to open it again, then repeat until it moves freely. This may be all you have to do depending on if there's a lot of slop in the guide after you get it freed up. If there is, then you'll have to replace the valve guide and possibly the valve as well. P. S., if it wont move with gentle tapping, don't get carried away or you'll bend the vale stem and that wouldn't be good at all. This is just my $.02. It has worked for me in the past. There may be more suggestions to come too. Hope this helps.
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#3 olcowhand ONLINE  

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Posted January 20, 2011 - 06:46 PM

Just a little addition, if you have a brass or aluminum pin to use, place it in the center of the valve to ensure you don't accidentally hit the outer parts of the valve, which could bend the stem. As light as a tap as it will be, I just use a steel pin, but for advising others, I stick with recommending a soft metal drift pin.
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#4 caseguy OFFLINE  

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Posted January 20, 2011 - 07:01 PM

Just a little addition, if you have a brass or aluminum pin to use, place it in the center of the valve to ensure you don't accidentally hit the outer parts of the valve, which could bend the stem. As light as a tap as it will be, I just use a steel pin, but for advising others, I stick with recommending a soft metal drift pin.

Thanks for adding that Dan! Not sure where my head was, but that's the way to go!

#5 NUTNDUN OFFLINE  

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Posted January 20, 2011 - 07:51 PM

Please let us know how you make out :D

#6 DH1 ONLINE  

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Posted January 20, 2011 - 08:39 PM

It may sound a little violent, But you'll want to use the spray lubricant of your choice (Aerokroil, P.B. Blaster, WD40, etc...) and lube up the valve stem liberally. Make sure that the cam lobe for the exhaust valve is 180 degrees away from the valve stem (i.e. a gap between the lobe and the stem), then use the smallest hammer you have, a brass one is really nice because it wont mar the valve head, and tap lightly until it begins to move. Once it seats, you should be able to rotate he cam lobe back up to open it again, then repeat until it moves freely. This may be all you have to do depending on if there's a lot of slop in the guide after you get it freed up. If there is, then you'll have to replace the valve guide and possibly the valve as well. P. S., if it wont move with gentle tapping, don't get carried away or you'll bend the vale stem and that wouldn't be good at all. This is just my $.02. It has worked for me in the past. There may be more suggestions to come too. Hope this helps.


Done the same thing a couple of times, used a brass drift though.

#7 Texas Deere and Horse OFFLINE  

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Posted January 20, 2011 - 08:51 PM

Sometimes I have had to use Carb. cleaner on stuck valves and then blaster. I also use the handle end of my hammer, less likely to bend the valve. I've done that before, being too agressive.:wallbanging:




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