Oh! Oh!

this is a engine that very few of us know much about but do you have a case vent on this engine?

I don't understand the frothy part but without a PCV most 4 strokes don't run right.

Sounds like too much crankcase pressure.

Exactly as JonnyR said. However on these small engines you can do a vac PCV with a check valve and a inline fuel fitler from local auto store. The oil dropplets that do make it up into the pcv pass the check valve will hit the filter and collect, then upon shutdown drop down back into the crankcase.

Ah man, you beat me to it. I've been wanting to put a Z50 clone on a bicycle for quite a while. I know a bit about those engines from my time with mini-choppers. All of my engines had a crank ventilation tube on them. Every now and then, a little oil would drip out, but I mean very little oil. Still, each engine had a ventilation tube, but I don't see one on yours. The tube was always on the top side of the crank case, and there was usually a clip further down the back of the engine to hold the tube in a proper position. If you DO have a ventilation tube, maybe it has somehow become clogged.

The frothing is probably due to the fact that the gear box is lubed by the engine oil. Even in neutral, there is a whole row of gears that spin with the RPM's of the engine. I don't know how frothy that would make the oil, or whether your oil is abnormally frothy, but I can imagine that that could be the cause for the frothiness.

Don't know if any of that helps, just giving my $0.02.

Yep, you have capped off the case vent. I always ran an inline fuel filter on mine for an oil separator as someone already mentioned. A long hose was all Honda used on a Z50a, just ran it back & dumped it in front of the rear wheel.

Your oil is cloudy with condensation. Because it has no case vent the moisture can't leave & it builds up. Open the case vent, and ride it for a while to warm the oil up.

B.

And when it's cooled down and settled afterwards, check the oil level. If it needs it, top up. Water, even in suspension, occupies volume. If you boil it off by running the engine, then there will be less fluid in the engine.

That's one sweet looking bike btw Delsiii! I must've missed your build thread *doh*

Delsiii said:

I just started it today and thought I will go for a quick scoot... Well not so fast for you...... Its a 70cc Lifan , starts fine, sounds good,but after about 2min of idle a little of internal rumble and I shut her down ... Then a little oil leak from where the clutch gasket is (its auto) and a little off color ,maybe frothey I guess you would say , but when I opened the oil filler plug it was under a fair amount of pressure....Any Ideas on that?????Chow

Click to expand...

Delsiii, if you bought this engine new, please please please tell us you changed the oil that was in the engine.

Change the oil right away before you start the engine with 10w40 non-synthetic oil. The oil that comes in the engine is ONLY to be used if someone accidentally turns the engine over. This is LOW-QUALITY oil that should not be run. 900ml oil MAX

Best oil for these Honda CT70, Honda Mini Trail 50's, Honda crf50's CLONED engines ( LIFAN ENGINE ), IMO, is The Powroll brand motor oil is the best oil you can use for your air cooled, wet clutch equipped Honda Minitrail Clone / Lifan. It has a high zinc content (great for new & old motors) & keeps it's viscosity very well. Powroll recommends the straight 40 weight oil for temps above 30 degrees F. & the 20W50 for temps below 30 degrees F.

Powroll has very good information regarding motorcycle oil and engine break in procedure on their site here Powroll:
http://www.powroll.com/tech_specs_OIL.htm

* Oil capacity & oil level checking method:

To check the oil level on the bike, hold the bike upright, remove the dipstick, wipe it clean and re-insert the dipstick without screwing it in. Just place the dipstick in the hole & pull it back out. At that point, the stick will display the level. The exact capacity is going to be between .80-.85 of a US quart, but a full quart will not hurt.

Powroll 20W50 grade Micron Moly Racing Oil is No.1 IMO. Available by clicking this link:
Powroll Oil http://www.powroll.com/tech_specs_OIL.htm
or call * 541-923-1290*

C.H.

My goodness, that's a nice looking bike.

Glad to know you got the oil problem figured out now.

These bikes are sexy! I love your spring seat! A completely new take on it!