Possible engine problem or just fouled prop

[eddystone]

Beta 30/Featherstream/Sadler 32. Boat has had little use since early summer and I suspect prop badly fouled. I think I’m losing 1.5 to 2 knots compared to normal and exhaust temperature up to 44 degrees C where normally rarely exceeds 40. Little bit of white haze but healthy water flow. Could all of this be down to fouling? Because it’s quite a big engine for the boat the prop has quite a fine pitch and I wonder whether that makes the fouling have more impact.

 

[RAI]

Have you checked the raw water impeller? Maybe it's lost a blade or three.

 

[eddystone]

I will check that

 

[srm]

You have probably answered your own question. Why not put a face mask on, or use a water glass (a sort of long glass bottomed bucket) and have a look see. The rate of fouling growth can vary greatly from location to location and also from one year to the next at the same location. Once established the rate of growth can increase quite quickly. The solution is to use the prop frequently to stop the initial growth from establishing.

 

[Bobc]

Almost certainly fouling

 

[englishrobs]

Beta 30/Featherstream/Sadler 32. Boat has had little use since early summer and I suspect prop badly fouled. I think I’m losing 1.5 to 2 knots compared to normal and exhaust temperature up to 44 degrees C where normally rarely exceeds 40. Little bit of white haze but healthy water flow. Could all of this be down to fouling? Because it’s quite a big engine for the boat the prop has quite a fine pitch and I wonder whether that makes the fouling have more impact.

Had this last year. Same equipment on contessa 32. Fouling.

 

[oldharry]

Eliminate the simple bits first.... fouled prop is quickly identified and easy to rectify for example. Partially blocked fuel filter?

There's no point in going in to the engine itself until you have dealt with any external causes which are the most common issues anyway.

 

[Bilgediver]

You have probably answered your own question. Why not put a face mask on, or use a water glass (a sort of long glass bottomed bucket) and have a look see. The rate of fouling growth can vary greatly from location to location and also from one year to the next at the same location. Once established the rate of growth can increase quite quickly. The solution is to use the prop frequently to stop the initial growth from establishing.

I made a prop inspection tube out of a plastic drain pipe with perspex disc at one end. Can use it from the pontoon or dock.

 

[eddystone]

I tried to get some off with a stiff brush fixed to a boat hook but water is far too murky to see. Checked impeller which is OK but I can run engine at high recs in neutral and all seems fine so I think it’s all down to fouling.