Quote:

"anything' that causes a misfire is going to as an after-effect also cause popping in the exhaust.
You can swap in new plugs and wires if you are about due. If you have the opportunity, you can also start it and allow it to run for a bit while it's rough, then shut it off and compare plugs to determine which cylinder(s) are missing.
If it's a coolant leak, the exhaust will have a sweet smell.


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That's the thing, no sweet smell or white smoke. Last time I adjusted the valves I tightened the lash a little more than I have in the past but that was last fall and it ran good after that. I'm thinking I've got a valve that's too tight and not sealing until it warms up but lash loosen over time not tightens?