engine smoking, Help

[seapro2u]

I have twin 2003, z-150 , 2 strokes and the starboard motor has blueish smoke at idle or slow speeds, the motors have 850 hours at mostly *****ing speeds.Both run great and have same wot rpm.The low pressure fuel pumps all were replaced last summer with about 100 hours since that repair.I have only used yamalube or quicksilver oil in the resevoir.Is this a sign of impending doom or something else that may need repair?

[bumperfood]

Sometimes you will get that if the thermostat is stuck open, or opening too soon. You can take it out, if its open when you take it out -best to replace. You can also check its operation by suspending it in a pot of water and heat the water up on a stove burner, check the temperature that it opens at against specs for you engine. If you operate in salt water and don't flush each trip you may end up with salt crystals holding it open or stopping the shaft from moving.

[seapro2u]

Thanks for the suggestion. I will certainly give that a try.