0-200 not running on 2 cylinders

[nbjeeptj]

My zodiac 601xl has a 0-200 engine in it with low hrs. Just had annual completed a few weeks ago, and I have only went flying one time since then that ended quickly due to my stall warning going off and not stopping. I just circled the pattern and landed. They fixed the stall warning so today I decide to go enjoy the afternoon and during my preflight after starting my engine it was running rough and the two cylinders on the left side would not rise in temp. The EGT for the left side cylinders was cold. I would have thought a mag could have been bad but that would not be right since it would affect the top or bottom side of all cylinders. Any Idea what could cause the 2 cylinders to not run but the other 2 to act normal?

[FlyingForFun]

Delete

[3Dreaming]

Do you have a 4 point EGT or just left and right? If it is just left /right then you could have just 1 cylinder down that has the probe. If it is just one cylinder I would guess a stuck exhaust valve. The O-200's will do that on a diet of 100LL if you don't use some kind of upper valve lubrication.

[nbjeeptj]

4 point and it was either 1 and 3 or 2 and 4 that was barely over the cold temp

[nbjeeptj]

A&P found a stuck intake lifter on Cyl #2. Only way to get lifter out is to split the case. That should be cheap!

[3Dreaming]

A stuck intake valve will sure mess up how the engine runs, because it messes with the airflow to the other cylinders as well. Normally a stuck valve doesn't mess up the cam follower, but if it is broke the only way to get to it is by splitting the case. I had to do that on a C145 a few years ago, because an other mechanic messed up a follower.