AC 160 lacks power, or something, I think

[mundamanu]

It is a Perkins 3-cylinder. The popping noise is coming out of the exhaust.

Is a burnt or tight valve one of those not good or inexpensive things that Ken Sweet mentions above? /forums/images/graemlins/confused.gif

 

[CMunger]

The camshaft lifters are in the cylinder head on a 152. The least expensive thing to do first of all is to remove the valve cover and check the valve to rocker arm gap, adjust the valves, as it would be refured to. The adjustment bolt is in the top of the lifter and is a simple procedure. The gap is .010 cold .012 hot. To be honest with you it my gut feeling you have a broken intake valve spring, or a burnt intake valve, or the valve could have something under it not allowing it to close.
Chuck M.

 

[MMM]

I'd do a cyl power test first. Loosen each inj line and listen for rpm drop or rough running. Cyl that doesn't make a difference is culprit. Notice fue delivery to each inj also. If you find bad cyl, swap inj to different cyl and see if problem moves. Look for wet tip on inj, dribbling can cause pop aslo. Not sure about your engine, but might want to drain water when you pull inj as sleeves will sometimes come out with inj and flood cyl.......water in oil etc.