Black Build-up Prop Exhaust

[Matt1212]

I run the 'Cocktail' in every tank of gas. Always had engine serviced (09 250 Pro XS). RPM's and Water pressure fine. Have a black 'carbon?' buildup on the inside of the prop. Any cause for concern?

[pietco]

I would like to know also

[196 Bobby]

I have carbon build up on the inside of my prop also (200 Optimax) and I think it's the "cocktail" doing its job getting the carbon out of the motor. Three years and no problems.

[EuropeanAM]

This is usually an indication of either a mechanical problem, fuel delivery problem, OR an indication of "excessive low RPM Runtime".

Running the engine in the 4000-5000 RPM range (4500 is usually perfect) for at least 5 minutes near the end of your boating outing can help to keep these performance-robbing carbon deposits to a minumum.

In addition to the above, and regular use of QUICKLEEN in EVERY tank of fuel: Running the RECOMMENDED engine oil (Optimax/DFI oil for ALL STANDARD and ProXS Optimax Engines) also helps to keep carbon levels to a minimum.

[196 Bobby]

Mine was from excessive idling. My 8 year old liked to "drive"

[Baja 252]

Don would running just above idle, say 800 to 900 rpm produce more or less carbon build up compared to running at idle?

[EuropeanAM]

Very similar. Ultimately, the CLEANEST engines we find are those that spend the majority of their runtime in the 4000-5000 RPM range.

[cpacheco]

Running quikleen and switching to dfi oil made mine run much cleaner

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by cpacheco &raquo;</td></tr><tr><td class="quote">Running quikleen and switching to dfi oil made mine run much cleaner</td></tr></table>

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