Synthetic Oil = Lots of Smoke?

[balistikb]

Hello all, I have read a bunch of posts here saying that changing to synthetic oil would help decrease engine smoke while running.
I changed my oil and replaced it with marine Pennzoil 100% synthetic oil.
To my disbelief, my engine is actually smoking more. Not just a little but 007 smoke screen type of smoke.
What happened? Why am I getting this result?
I have a 1999 Mercury EFI 250.
Thanks for any help you can provide.

 

[jmburock]

Re: Synthetic Oil = Lots of Smoke?

Mine did the same thing when I switched to Pennzoil synthetic after years of Quicksilver Premium plus. Perhaps the Pennzoil has better cleaners in it that are mixing with the carbon and burning it up as smoke. I switched back to Quicksilver b/c my wife complained about the smoke.

 

[balistikb]

Re: Synthetic Oil = Lots of Smoke?

I am wondering if I should switch back (lossing money) or wait it out till smoke clears up.

 

[balistikb]

Re: Synthetic Oil = Lots of Smoke?

Any other thoughts?

 

[balistikb]

Re: Synthetic Oil = Lots of Smoke?

Can anyone else add their thoughts?

 

[j_martin]

Re: Synthetic Oil = Lots of Smoke?

The VRO has an adjustment for idle mix. Make sure it's on the line. Sometimes you have to set it a bit leaner to limit idle smoke.

Look in the maintenance manual for the adjustment.

I like pennzoil. I think it smokes a bit less, and seems to be a superior lubricant. I noticed that if I get in a situation where I have to idle a long time and the smoke comes back over the boat, it'll deck the first mate in a hurry.

hope it helps
John

 

[verado7]

Re: Synthetic Oil = Lots of Smoke?

last poster got it right - when you switch to synthetic or even brands of oil you will have to adjust the oil delivery - synthetic flows faster so you need to turn down the pump . by the way not all low smoke oils actually do what they claim - i have tried numerous and have personally found esso synthetic blend gies off less smoke and thats in my old 88 classic fifty mixing the oil in the gas tank but again in your unit you will have to slow down the delivery system .