Effects of Fouling?

[elvis]

I have a Maxum 2100 sports cuddy with a 5.0l Mercruiser which I purchased & launched in September 2005.

Initially I could a get a top speed of approx 47mph @ 4300rpm with optimum trimming. However during the last couple of weeks Ive been pushed to get more than 40mph which strikes me as rather a drastic reduction in such a short space of time.

Is this to be expected in the space of 5 months?

The boat has had little use since October thanks to the south coast weather. The prop & outdrive are looking a little on the green side but from the surface the hull looks fairly clean.

How drastic are the effects of fouling in such a short space of time, could this be the cause of the speed loss?

 

[Dave_Snelson]

The effects of fouling are drastic. Not sure as they are as drastic as you describe, but then again, I don't know about Maxum boats. With a fouled hull with say 1/3 barnacle coverage you could lose 5kts.

 

[rich]

Clean the hull and drive,take it out for a run,you will be happy,I guarantee.

 

[mjkinch1]

Just a thought for you - I had exactly the same boat, but a 2004 model, and I had a problem with the engine dropping revs - it would generally happen after a short period. Anyway complained to dealer and it turns out there is a known fault with the engine management system, that causes this. The EMC was replaced and hey presto back to top speed. Worth asking the question of your dealer, although if your boat is a 2005 model they may have fixed it by then.

Martyn

 

[thefatlady]

A few years ago I bought a 21ft outdrive boat which was initially very badly fouled. Boat was only 18 months old, but had been just sat in the water for much of that.

Top speed on first trial about 15 knots and would not get on the plane.
Pressure washed off antifoul. Top speed then 33 knots.
Removed antifoul back to polished gelcoat. 43 knots.

 

[elvis]

Thanks for the responses, I'll give it a clean.