Oil filtration

[Ludwig II]

I can't see any mention of an oil filter even in official Honda manuals about any of the GX engines and their clones having one; do they have them, and are the engines hurt if by it if they don't?

 

[motorbikemike45]

To the best of my knowledge there are non of the 4 cycle "micro" engines that have oil filters. The small Hondas and Robin Subarus don't have an oil filter and, of course, 2 cycles engines may have a fuel filter that would also filter the oil mixed in the gas. The Subaru-Robin EHO 35s I used to run carried only 80-100mL of oil and I changed it very often, because there was no filter and only 2 quarts of oil would last more than an entire year. Change the oil often and it shouldn't be an issue. Remember, these little engines don't have a regular oil pump, so there is no simple effective way to put a filter into the system. Most use a pulse from the piston moving down the cylinder to "pump" oil in a mist around the crankcase, onto the cylinder/bottom of the piston, and up into the vavle train over the cylinder. It sounds sort of goofy and primitive and quite ineffective, but it works very well and has proven over time to be effective.

 

[Ludwig II]

I'll be doing that, but I'm just surprised there isn't even a wire mesh strainer or a centrifugal type like small Honda motorcycles have. I suppose it's a competitive market, and the average user of these machines probably doesn't do much maintenance anyway.

 

[motorbikemike45]

If the average user is a landscapper or grounds keeper, they are his tools of the trade and they generally maintain their equipment very well. If it is a homeowner, then you are probably right. A centrifugal oil filter, like we had on our Honda bikes were pretty good filters, but they need the oil to be pumped through the filter and there is no pump.

 

[Ludwig II]

Well, I have the bike to start on now, a lady's frame and the engine will sit on top of the higher of the 2 tubes, up against the seat post. I suppose it could be possible to angle the filler/drain towards the ground to make emptying it easier. I'll have a look and see once I've ordered and received an engine, which will be a 139F or a GX35 copy. Whichever one it is, it will be restricted to pass the Low Power UK regs, so it won't be working flat out ever in it's life.

 

[tooljunkie]

small engines have been running without 710 filters since the beginning of time.
change oil often and keep air filter in good condition.
dusty conditions require more frequent service.