Small Engines (Lawn Mowers, etc.): No compression on one cylinder, fly wheel, head bolts

Question
QUESTION: I have a B&S engine, model 303447. I recently changed the head gasket on one cylinder because there was oil leakage around it. I had to remove the rocker arms and push rods to remove the head. The fly wheel was moved slightly while the head was removed. After reassembling  the head I have no compression, and gas shooting out of the carburetor when the engine starts. Is the timing off because the fly wheel was moved,and how do I correct it if so? If this is not the cause what else could be causing it to do this?

ANSWER: Did you adjust the valves in the head you removed?  Is a push rod bent?  I doubt the flywheel key is sheared but you can check just to be sure.  Flywheel keys on the larger engines are not prone to shearing unless there is a significant problem.

Let me know if the valves were adjusted or is a push rod is bent.
Eric

---------- FOLLOW-UP ----------

QUESTION: I didn't adjust the valves and the push rod does not appear to be bent. I made sure the push rods are properly seated and the rocker arms are moving freely. The valves move, and the intake valve seems to be seating, this is hard to verify without removing the head. This may be my next step. The valve spring looks to be positioned correctly also. As far as the flywheel is concerned I believe it is ok because the engine will start and run on one cylinder. The push rods are not identical but are the same length. They have different ends. Could the problem be that I put them on the wrong valves? Let me know what you think.

ANSWER: Did you torque the head bolts.  Since the head was leaking oil, is it possible it is warped and leaking?  Do you have a compression leak down tester?

This link describes how to adjust overhead valves:

http://engines.myfaqcenter.com/Answer.aspx?p_faqid=3441&body_0$tbKeyword=valves

Did the cylinder have compression before you replaced the head gasket?

Eric

---------- FOLLOW-UP ----------

QUESTION: I did torque the head bolts to specs. I do not have a compression leak down tester. Not sure what it is. I believe I had compression prior to removing the head. The engine would stay running under a load ( pto engaged and mower deck running). Now if I engage the pto the engine dies. I read the link on overhead valve adjustment and will try this tomorrow. Thanks for the info, will let you know the results.

Answer
Do you have a compression gauge to measure and compare the compression between the cylinders?  Compression gauges are more common but you can purchace either tool from Harbor Freight at a low cost.

Check the vavle clearance.   An easy way to check the push rods to see if they are bent it to roll them on  piece of glass.   If the rod appears to wobble it is bent.  

I'm still curious about the compression difference between the cylinders.  The compression needs to be verified to see if that is the problem or if something else is the cause.

Let me me know what the valve clearance is.

Eric