My 35 hp GTR has a little bit of white exhaust smoke after letting off throttle and going back to idle. It's mainly only noticeable at night with a light shining on it but I didn't notice it until after I installed a new cam this summer. I put new gas in and run seafoam to make sure I didn't have moisture in it. I checked compression, both cylinders are about 117-120 with the motor cold and warm. I put a little oil in the cylinder and compression came up to 125 on both cylinders so I don't think it's the rings. The plugs don't look wet. I've checked and reset the valve lash a couple times in the 8 hours I've put on it since installing the cam. Oil level has always been good and I even drained a little out to make sure it wasn't over filled. Oil doesn't smell like gas. Do you think I'm actually burning oil or did I do something else when I put the cam in? Should I buy a leak down tester to check the valves? Maybe this is all in my head and there isn't really anything wrong!
Motor is a 2011 with 150 hrs on it. The heads were already worked but that was 100 hours ago.

Plug color looks good to me, definitely not too rich or lean. I only run premium with no ethanol. It happens on a cold or warm engine.

Thanks for the advice anyway! As long as it's nothing major, I'm happy.
Anyone else have an ideas?

if it starts and seems to run fine, I wouldn't worry about it. just keep a eye out to see if it gets worse.

I get to the landing, pull the plugs, turn the motor over till all the gas flies out the cylinders, then rail on it for hours crawfishing, if it runs it got to work or blowup. lol

If you can only see smoke at night with a light that's not as bad as you think. I've noticed the same thing while frogging. If I'm idling and not staying in throttle a lot I do get some loading of fuel in cylinder. Maybe by adding the cam your valve duration is held open a little longer and is causing light smoke only visible with a light at night. Now if you see smoke in daytime while running it could be valve stem seals causing some smoke. But if you can't see any during daytime then I'd think your ok. You checked all the necessary things and it all looks good.


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