Perkins Perama M30 Volvo MD2030 Low Revs in Gear

[seajayare]

long time later update. All appears to be sorted for me now but I didn't find anything specific to pin things on. All filters changed and bled for hours, exhaust elbow checked and clear, injectors checked, compression checked, saildrive checked for tightness, prop checked. Nothing found anywhere. Boat back in the water after last lift to investigate and all seemes ok again. Only thing actually altered was the alternator was checked over as it had stopped charging due to sticky brushes. I am left wondering if it was actually just something odd with the alternator causing the tacho to under read. Anyway I am a bit uncertain about things that heal themselves but for the moment it's goid news and next week I will test and see if it stays good news

 

[TNLI]

OFF TOPIC:
Any Perkins experts have a manual or data sheet showing the locations of the engine mounts for a Perama M 30 ??
No luck in Google, just engine dimensions, and I'm curious to know if it will fit the mounting brackets for a BMC 1500?

Back on topic, if you have a rough runner and have tried all the obvious checks and adjustments, I always check for sludge in the sump by pumping out a little used oil and looking down the filler entry. If it is sludged up, do not try and run it until it has been flushed out and new oil & filter used. I just use diesel and turn over by hand, pumping out each time until it runs clean. It's a good idea to then check to see if the oil pick up screen is cleaned up. Then when the worst of the sludge has been dissolved, fill with a high detergent oil and change again after 10 hours.

Liquid Moly make a very good direct feed injection cleaner for diesels, it's used in a loop from fuel feed to return line at lowish power and is far more effective than Redex or any fuel additive at cleaning varnished up injector tips. I think they call it diesel purge.