Too much compression. adjusted the valves and it got worse

[CJSNIDER]

In My opinion there is no such thing as Too Much Compression , never saw it in over 50 years on working on all sorts of machine

Try starting a Briggs with a worn camshaft, or a two-stroke with carbon build-up on the head and piston, and you will find out first-hand about compression.

 

[CJSNIDER]

I service a lot of mowers and have had to replace several cams. If it had no valve gap meaning the valves were being held open, it should have turned over easy. The less gap you have the easier it should turn over. That being said which from your description it sounds like at some point someone before you got the engine, adjusted the valves real tight to make it start easier. Because cam wear makes the gap larger the only ways they could be too tight is someone adjusted them too tight, the push rod guides are worn, or the cam bearings/bushings have caused the case to wear and, in some way, caused the cam to be positioned closer to the head which is most unlikely. One other thing to check before tearing engine down is the push rod guides, if the (plastic in some cases) guide is worn it can allow the push rod to move out of position and tighten the valves. I have seen this too but, in most cases, it will come out from in under the lifter.
These engines depend on everything being right for them to run correctly.
What I would do in this case (if the push rod guides are good) is to remove the engine and take it apart so I could inspect the cam and can bearing/bushings. Also, if the cam is shown to be worn or the relief is not working you should check the oil pump to make sure it is pumping oil good and has no wear. Because something caused that cam wear or relief problem. Another thing is to look at the cam follower which is caps that ride against the cam and make sure they are free moving.
This sounds like a worn cam that the valves have been adjusted tighter or the push rod guides have worn and allowed the push rod to come out of the indent in the lifter and not completely out from under the lifter.

When the valve face and valve seats in the head wear, the clearance is reduced.

 

[sessman55]

Your compression release on the can is shot. Buy a new cam and sump gasket kit.

 

[Hammermechanicman]

Does no one have a B&S shop manual?
Manual says remove plug bring piston to TDC. Insert screw driver, turn PAST tdc 1/4 inch then adjust.
Solved my starting problem.

What's a shop manual?

 

[Earthquake Landscaping]

What's a shop manual?

A "Shop Manual", is what you put under your beer, so that you don't get white rings on the coffee table.

 

[Hammermechanicman]

A "Shop Manual", is what you put under your beer, so that you don't get white rings on the coffee table.

Good to know!

 

[BillS2019]

It has nothing to do with the valves.

 

[2ball]

It has nothing to do with the valves.

That is my exact engine and my exact issue, but If the mower keeps starting, I will keep pushing that fix back.

 

[BillS2019]

My Kohler has the same issue. Been that way for 5-6 years and I will just keep rolling it off compression by hand.

 

[2ball]

Just reflecting on this. Three years ago I got the mower with a blown engine free. I replaced the engine with a used engine. A new engine was somewhere in the $500 range. 3 years have passed and if I replace the cam shaft, I will be in at least $350 on this used engine. I probably made the wrong decision not buying a new engine.