Perkins 4236 fuel injection problem

[Ashman]

My Perkins 4236 had become irritatingly smokey so I replaced the injectors and injection pump but it didn’t cure the problem. The engine is nearly 40 years old with 3400 hours on the clock although it rarely requires a oil top up between oil changes and runs like clockwork. Compression and oil pressure are good so I am reasonably confident the smokey problem is still due to fuel injection.
When I replaced the injection I aligned the timing marks exactly but it didn’t stop the smoke. I was told by the supplier that I might have to tweak the alignment as the engine’s timing gear was probably worn by age. This made sense to me but adjusting the fuel pump clockwise or anti-clockwise by a degree doesn’t seem to have made any improvement.

Am I correct to think that I should be advancing the injection pump timing to offset the engine wear and if so how much, would 2 or 3 degrees normally be sufficient?

My other question is more of a sense check, in order to advance the timing should I be rotating the pump on its mountings in the opposite direction to the arrow shown on the side of the injection pump (presumably the shaft rotation direction).

Any of your thoughts or suggestions would be appreciated……I am at the end of my tether cleaning soot stains off the hull!

 

[sfellows]

If it's black smoke and sooty then it's likely this is a lack of air - have you checked that both the air intake and the exhaust systems are not blocked?

 

[Ashman]

Good points. I make a habit of checking the perforated drum air cleaner although I might try running the engine without it as an experiment. Your point regarding the exhaust might be valid. I had a repair made to the flexible section of the exhaust dry riser and I wonder if it has increased back pressure.