Decompression valve

Fmkehoe

Forum Newbie
Joined
Aug 2, 2021
Threads
3
Messages
7
So how difficult is it for a reasonably talented person to take the engine apart and change the compression valve?
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
91
Messages
11,476
Very very hard to do since the Briggs don't have one.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
59
Messages
15,305
First there is no decmpression valve on today’s small engines. Depending on the age of the engine you have an ACR (auto compression release) mounted on the camshaft or a small bump on the intake lobe of the camshaft.
 

Fmkehoe

Forum Newbie
Joined
Aug 2, 2021
Threads
3
Messages
7
First there is no decmpression valve on today’s small engines. Depending on the age of the engine you have an ACR (auto compression release) mounted on the camshaft or a small bump on the intake lobe of the camshaft.
OK, so I got the terminology wrong, I’m sorry. Yes I’m talking about that large gear with the lobe on it that takes the compression away while the engine is cranking.
 

Ocean909

Active Member
Joined
Aug 11, 2022
Threads
8
Messages
76
Replacing the camshaft is not difficult. The devil is getting there and back. Gather everything you need before hand. Gaskets, oil seals etc. Be prepared for broken bolts etc. Take lots of pictures and label and separate things as the are removed. Make sure the timing marks are lined up and most important remember the oil before starting. You'd be surprised what you can forget when you get tired.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
59
Messages
15,305
This project just took a sideways turn. If you replace the camshaft you are going to have to check the valve clearances and most likely have to adjust them. Now you have added a new direction to your project. This will not be easy unless you have an OHV engine. Post all engine numbers and we might find a service manual for you.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
91
Messages
11,476
Now there you go Rivets. It all about which Briggs engine the OP has. And sometimes with OHV all that is needed is a valve adjustment.

And on some you strip out the threads of the sump so be prepare with some Helicoils. For some reason the 31 series OHV are bad strip out the threads.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
59
Messages
15,305
Star, I don’t understand your comment about me or my post? I can just go from the info the OP provides. He asked how difficult the job would be and I gave him the best answer I could, depending on which engine he had. If my answer is wrong, what is your expert response based on the info he has provided. I even requested engine numbers, which you are constantly complaining people don’t provide.
 

StarTech

Lawn Royalty
Top Poster Of Month
Joined
Feb 19, 2020
Threads
91
Messages
11,476
Have you ever received a compliment? That like saying Good Work there.

Sorry I recouping from dealing with SearsPartsDirect today. The idiots is saying it politely.
 
Last edited:

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
59
Messages
15,305
Many times, but never from you. Most times just questioning my replies. This would be a first.
 
Top