The Scrappy Oil Catch-Tank Project....

It should fit on the right side between the frame and the outer plastic.....somewhere around the upper shock mount. I'll run the other line over to the left side, then forward and down to the valve cover. I haven't even looked under there yet......but I've been in there a bunch of times, so I sort-of know what I'll deal with.

I haven't decided about the output from the PCV valve.....might run it to a PCV filter. That's how the valve cover is venting right now. I'm also curious if this device will fix my little leak from the left crank seal.

Quality....looks good to me. The canister is all aluminum, and the three fittings on it are replaceable if you could find some of the right size. That second input fitting should have been the size of the OEM valve cover vent hose, but it'll be OK with the adapter.

Here's where it'll probably end up.......



In theory.....the intake end of the canister should point downward (somewhat anyway), so any oil blown into the canister will drain back into the engine when the engine is stopped. In this location I can get a fair downward tilt.

Mounted like this it is critical that the hose has free play, since it will be moving with the suspension. The alternative would be to mount the canister on a section of the engine/transmission/rear fender so the hose didn't need to move independently.

It's going to take a while to figure out the best place.......more to come.

One more thing here....I really don't understand how Scrappy's PCV valve can work very well, if at all.

On a car the PCV valve opens when the engine is running, with the intake sucking in the fumes from the crankcase.

On this setup presumably.....the valve is simply venting the fumes from the crankcase to the atmosphere by opening/closing using the varying pressure pulses from the crankcase (as the piston moves up/down). This means the spring-loaded PCV valve must be opening/closing at engine speed, in order to achieve a partial vacuum in the crankcase. Doesn't seem possible......

Perhaps this valve would actually work as a PCV valve, if the clear valve output line in the photos, was routed back to the engine intake.....there were no instructions with this device, or the aluminum catch-can either.

Anybody who can clarify this thing.....please chime in.

Here's what Scrappy says about this valve.....

"This nifty device actually creates a vacuum within your engine by only allowing air out, and not back in. Made in the USA all steel construction easily attaches to your vent line, which should be place above your engine as far as possible, and installed on the barbed nipple end. Threaded end is left open, or attached to a filter if you wish."

Update.....did an oil change this morning. The quick fitting works just fine. Afterward I did a 60 mile road test.....no leaks, no incidents. There was no oil visible in the clear vinyl hose.....at the very end I could feel a very slight bit of oily vapor residue. This is about the same as the previous single vapor vent hose to the valve cover.

A test at 35 degrees is not the same as testing this thing at 100 degrees however.....that hotter test will have to wait a few months.

Just from looking at the photo of Enviro's stainless catch tank, it's hard to tell everything. It looks to have a single port (inlet), and a fitting to replace the dipstick like Scrappy's. I guess the stainless tank is supposed to mount above the engine, allowing any oil to drain back.....either that or the tank has a lid to unscrew to dump the oil.

The stainless tank doesn't look to have an outlet port....which releases pressure buildup. Puzzling. Plus it only has the single inlet from the looks of it.

I wanted to use both vent hoses going into a single tank....which could be high-mounted, and could be self-draining back into the engine. Scrappy's does that.

The other thing......the hose going to the new vent on the dipstick hole will get very hard in cold weather, and will almost be impossible to remove without damaging the hose and causing leaks. That's why I went to the quick-connect fitting. If you check the oil daily like I do in the summer, that fitting will be much appreciated. The quick-connection could be installed on Enviro's setup also.

I may be wrong in my assessment of Enviro's stainless setup, as I'm only going by the single photo. If anybody actually has one.....please comment.

Nothing much new to report......the setup is working well, with no leaks.

However....I was hoping the setup would relieve enough crankcase pressure to stop the small crank seal leak I have (variator side). It hasn't done that. I'm going to have to replace that seal anyway.....

Well, I got mine today and your absolutely right about the valve cover hose. There is no way that hose will fit on the other nipple. Where did ya get that hose enlarger/reducer? Something I can get at Home Depot? I may just replace the nipple with something smaller if I can find one Also, I had quit a bit of slag left on the dipstick threads. Easy enough to remove but, I'm glad you mentioned using the old rubber seal as mine came without one too.

Well, a little late but check this out. www.scooterpartsmania.com/rpm-aluminium-oil-breather-tank-system-88353-p-1851.html Look at the second pic and you'll see the difference. Dipstick built in and o ring provided. only like 5$ more but, the shipping is well

The problem is that the stock crankcase vent hose is very small.....way too small from the looks of it. This can cause excessive crankcase pressure......causing leaks and excessive oil usage.

The extra vent hose setup should fix that potential issue......so the theory goes.

Well that setup would work to vent the crankcase.....but the Scrappy catch-tank is somewhat different. Rather than simply venting the system to the atmosphere, the catch tank does what it's name implies. If mounted higher than the engine, it catches any oil blown into it, and allows the oil to drain back into the engine after the engine stops.

A simple vent hose like what's on there, can't do that. FWIW....the diameter of the stock vent hose on my 150cc scoot is the same as the vent hose on my 50cc scoot. Too small for effective venting in my estimation.....

Single cylinder engines are much worse with this vent thing than multi-cylinder engines. On a twin cylinder engine for instance, one piston could be going up while the other is going down.....not much pressure in the crank-case. You really need a big vent with a single.....IMO.

^^^^that last example is only a "for instance". A four cylinder car engine may be a better example. If I open up the dip stick hole on my Ford Focus, nothing splashes out.....try that on your GY6 engine and oil flies everywhere.