Positive Crankcase Vent Question

[retiredgentleman]

ReycleBill;

Does your engine still have the restriction (labrinth), and orifice, in the crankcase venting exit box?

If you can't run with oil level above the low level mark, that would indicate an engine with worn internals (rings, valve seals, etc). I have my oil level at about 3/4 of the high level mark and my engine does not use any oil. Also, there's never any oil seen at the pipes where the vent lines enter the airboxes.

 

[ReycleBill]

Several Hondas I have had dump the vent in the airbox and at the low point of the airbox they have a tube that ends at the dirtyside of the bike with a cap. Uncap it and drain off the guck at oil changes. You want to consider if you want oil that that has been in congress with unfiltered or poorly filtered air going back in your crankcase??

Thanks Gary, I'll keep that in mind. I think my biggest concerns might be that rerouting oil back to the crankcase might increase the amount of water, unburned hydrocarbons and sulfuric acid that gets into the oil due to the combustion process.

 

[ReycleBill]

ReycleBill;

Does your engine still have the restriction (labrinth), and orifice, in the crankcase venting exit box?

If you can't run with oil level above the low level mark, that would indicate an engine with worn internals (rings, valve seals, etc). I have my oil level at about 3/4 of the high level mark and my engine does not use any oil. Also, there's never any oil seen at the pipes where the vent lines enter the airboxes.

I think it's all still there. Mine is the one with the single outlet-- I have several of the older dual outlet boxes-- are they better?

 

[retiredgentleman]

ReycleBill;

I don't know if the single outlet is any different from the dual outlet, but I suspect they have the same internals.

It may be a good idea to remove the little box and check that it has not been modified. There is a labrinth type of tortuous path so that any heavy oil drops are directed downward and return to the crankcase. I have also heard that some PO's have opened up the orifice................better left as stock design.

 

[ReycleBill]

ReycleBill;

I don't know if the single outlet is any different from the dual outlet, but I suspect they have the same internals.

It may be a good idea to remove the little box and check that it has not been modified. There is a labrinth type of tortuous path so that any heavy oil drops are directed downward and return to the crankcase. I have also heard that some PO's have opened up the orifice................better left as stock design.

I had it off in the Spring when I replaced the gaskets in the top end and I think it's all there. I'll pull some off of some of my parts engines and see if they look the same.

I have read where others bored their outlets out but I'm not sold on that idea yet. The bike seems to be happy as can be just a few hairs above the low mark and seems to stay there-- maybe I should learn to live with it?