Smoky Perkins

[Saddletramp]

Not the country singer ( bound to be one with a name like that)

The real smoky Perkins is a 29hp M30. Took the fuel direct from a can to rule out fuel line probs.

Okay at low revs than black smoke when in gear. 'Throaty' sound according my mate, the hapless owner.

Reassured him the forum would have it sorted in a jiffy.

 

[npf1]

The easy things to try are:

is the prop turning OK - could it be fouled so overloading the engine

that it is pumping water (throaty sound can happen when no water is flowing), engine getting hot possibly burning off old carbon deposits or melting rubber exhaust hose.

Next try

that it is not overfilled with oil
the air filter is clean
the crankcase breather is clear

If none of those work, probably time to call in a professional as could be more serious.

 

[boatmike]

If the engine is in good condition then black smoke is only seen when overloaded. This sounds more serious. It could be as simple as an injector fault but that throaty sound sounds very much like a burnt out exhaust valve. Suggest a compression test might be in order. If that shows low compression its a head off job to investigate. It could also be gummy or broken piston rings.....

 

[Billjratt]

Get him to check the exhaust system for blockages and holes and make sure the water is going at normal rate.

 

[Saddletramp]

Comp test makes sense. He has taken the air filters off and disconnected the exhaust pipe to rule out blockages there. Plenty of water going through as well.

 

[scottie]

Check the exhaust outlet as the carbon up badly

 

[deisel]

I,m A Deisel Mechanic & Black Smoke Indicates Unburnt Fuel!
Go With The Compression Test, It Does Sound Like A Burnt Valve Or Possibly A Head Gasket Problem.

 

[boatmike]

If you are a diesel mechanic you should know how to spell your job! I before E except after C.... /forums/images/graemlins/smile.gif But I am glad we agree on practicalities. I think its the exhaust note that gives it away. Burnt out exhaust valves make a diesel "bark"

 

[ga1135]

Suggest you also check if there are fouling propeller. If yes, it
does make black smoke like overloading the engine. Experience found remove barnacles on propeller sort out the black smoke issue. Please try.

 

[Andrew_Fanner]

Check you can turn the shaft by hand with the gearbox in neutral. If you can't, it may be binding quite badly.

 

[woodemb]

You may be interested in why my Perkins Perama M20 gave out black smoke, and it was brand new at the time. Take a look at homepages.rya-online.net/emerald and Diary page 29 gives details.