Varnish buildup inside mechanical governor

artnadam · Mar 28, 2017

Hi guys...I have an Onan generator with a [1981] ford 300 six with a HOOF BD545E [obsolete] governor, just started overspeeding/auto shutdown. Took it off, drained oil, should have 3.25 oz, had 1.5 oz. Internal parts heavily coated with orange/reddish varnish. Original paint on drain plug, sure oil was original. I have seen that regular antifreeze dissolves this type of buildup. I would like to try to clean out as much as possible before returning to service, cannot find any printed info, parts diagram, repair parts etc. and would rather not take apart. Genset has less then 500 hours on original working hour meter.
Also in quandary about oil to use, have read that same engine oil as in engine, also read that ATF is correct.The old oil looks more like ATF then 30 weight.
Looking for opinions on cleaning without disassembly, and experience / suggestions on oil type.
Thanks for any help/opinions you guys can offer

rhunt · Mar 28, 2017

Art, that read/orange stuff is called Gliptal and is a type of varnish, not sure about that spelling, can't help with your problem though. Bob

Fallon · Mar 28, 2017

I bet any modern lighter weight oil would do just fine. If it were me I'd shoot some carb cleaner in a few times, let it drain out & dry out then fill it up with something modern & handy. Hydraulic oil, engine oil & ATF will all lube it well. In theory non-detergent oil would be better as crap falls to the bottom of the sump with that. Engine oil has detergents in it to keep crap in suspension to be filtered or drained regularly.

artnadam · Mar 28, 2017

rhunt said:
Art, that read/orange stuff is called Gliptal and is a type of varnish, not sure about that spelling, can't help with your problem though. Bob

Thanks, Bob! my vocabulary continues to expand!