A little black smoke when coming out of the hole?

[Hungry Man]

Is it normal to have a little black smoke when coming out of the hole?  I have perhaps a heat issue or a gauge issue to deal with, but when it read hot, 230 degrees, it puffed just a little smoke out the exhaust.  I'm not sure if it is normal or if i was extra sensitive to any problems because I knew the temp was up?  It cooled in seconds once the rpm's were up which leads me to the gauge grounding issue.  I have never seen a car cool in seconds with higher rpm, so I don't think a boat could either.

Any comments?

[PSullivan3]

Impellar.You should not let the boat idle too long.It just happened to me 2 weeks ago. If its a closed system and you just added coolant you need to burp it.

[Rambling Wreck]

My temp guage runs 20-30 degrees high when my blower is on - electrical quirk.

If I recall correctly, black smoke under acceleration is unburned fuel. I think buring oil is a whiter looking smoke. Some of you car buffs chip in here-

[wakejunky]

Black smoke under acceleration is an excessively rich fuel mixture. Which Epics are know for. Thats why we always foul plugs. Especially those that run alot of ballast. Burning oil is blue smoke. Burning water or coolant is white smoke.

As for the high temps- check the impellar and if its ok. It's probably the bad power and ground problem that we have talked to death several times.

[boneil]

I jus tried the hand check for temperature.  Run the boat hard for 10 to 20 minutes.  Grab the top of the exhaust manafold while the engine is still running.  Apologize if I "over simplify" (I need it that way for me)... the top of the exhaust manifold is two pipes that run at the base of the engine then shoot up to the level of the sun deck (on a v-drive) and then make almost a 180 and then go back down.

At 160 you can grab the top of them, but it's not at all comfortable.  If memory serves at the temp your guages are telling you... we would have to all get drunk and see who could hold on the longest... and the winner/loser with a 1-2 count will have a serious mark.

On my boat occasional puff of black on a hole shot normal...  When consistent puff of black smoke and running too rich dealer replaced everything engine related, short of the engine itself and including the main brain computer.  Dealer stopped swapping parts and changing plugs immediately after they swapped the MAF.