How To Repair Briggs And Stratton Compression Release On 21 Hp

Hullo Guys,
I see this thread is quite old now, but I came beyond a solution with the help of a buddy whose a small engine mechanic. I teach pocket-size engines at a high schoolhouse, and had the "besides much pinch" event in some of our v.5hp OHV briggs engines that the students tear down, measure and reassemble. I've attached a couple photos from the textbook I remembered I had once the local small engine guy tipped me off about the compression release.

Many Briggs and Strattons have a compression release system that relieves backlog pressure during the compression stroke by releasing a small amount of compressed gas through either the intake valve or the exhaust.

At that place are 2 main ways that they accomplish this. The first is through what they call an "Like shooting fish in a barrel Spin" pinch release system. They utilize a second raised side on the cam lobe to raise the valve slightly off of the seat immedietly prior to maxumum pinch pressure. Briggs admits that they'll have to do away with this in time due to stricter and stricter emmissions testing.

The 2d fashion, and more common way, is to utilize a mechanical release. The ones we have at school opperate simply past a weighted arm and a small-scale bound. The consequence nosotros had with likewise much compression was due to the piffling spring coming unhooked. My small engine mechanic friend said he repaired ane where there was actual pieces broke off, and picked upwardly on it because there was a fleck of damage to the cam from broken pieces that the customer claimed were never there in the outset place. (The customer must have opened the crankcase, chucked the compression release mechanism, and claimed it never happened.)

If yous're certain your timing is correct, every bit in you haven't had your camshaft out recently, or you're sure it's timed correctly, then follow the following procedure:

1. gear up valves correctly (make sure the piston is 1/4" down from TDC on power stroke, the reason it needs to be downward 1/four" is to ensure that the compression release isn't interfering with your valve lifter).

two. check compression release

- Remove the spark plug
- Remove the valve cover, turn the engine flywheel clockwise while watching the valve activeness.
- When the Intake Valve closes, stop.
- Now focus very closely on the valve jump retainer of the Intake Valve, continue turning the flywheel clockwise. In nearly 1/4 plough, you should see the Intake Valve Retainer (and valve) make another niggling move towards fully airtight.
- This indicates the Pinch Release is working.
- IF you see no movement, attempt again.
- Still no movement, there is a trouble in the Pinch Release system. When the engine is cold, you lot can residual the side of your hand on the caput and grasp the Intake Valve Spring Servant between yous thumb and index finger while turning as described and you should be able to experience the Retainer motility.

I've done a scrap of searching around on the internet and couldn't notice this solution. Hopefully it solves everyone's problems, and that your engine is sitting in the corner of your shop or garage somewhere, and hasn't been sold for scrap metallic! Again, ours was as piece of cake to prepare as reattaching a minor spring that had go unhooked.

How To Repair Briggs And Stratton Compression Release On 21 Hp,

Source: https://www.houzz.com/discussions/1644663/briggs-stratton-won-t-start-too-much-compression

Posted by: ramirezaboyed.blogspot.com

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