Diesel surges

[Hzale]

I have a 4d61 layman diesel in an albin 27. Every hour or so the engine will rev up 150 to 200 RPM for about 5 seconds and then go back to normal RPM. I normally run at 2300 RPM. I've changed the fuel filters, although if the fuel filters were clogged I would expect the engine to drop a few hundred RPMs and then pop back to normal, any ideas what might be causing this. Thanks in advance for any help.

[rsn48]

Ask this on the trawler forum, they even have an Albin user group as one of the forums sub-sets. A number of active Albin users there:

https://www.trawlerforum.com/forums/