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Fuel: In ALL my gasoline powered model engines, both 2 and 4 stroke, I use 96 (or is it 97?) octane ethanol-free pump gas. The alcohol has a detrimental effect on the rubber parts of the walbro carburetor. As for the octane content, my understanding is this is directly tied to compression...

-The C&H conversion was easy-peasy. One could also use the Moris Mini Motors conversion. Straight drop in. -Yes, spark plugs are 1/4-32 -This ignition I got from C&H is marked "6volts" but they vary. Expect somewhere around 300mah draw. -Sadly, I didn't do a thorough analysis of the specs...

The Gemini twin is horizontally opposed with the rods on their own journals so the piston motion is perfectly opposed. Since both pistons achieve bottom dead center together a substantial pressure pulse is generated. Perfect for powering the Walbro pressure pump. I just measured the venturi...

You are absolutely correct, Vetti! I'm confusing my percents and ratios - but even that isn't correct because 20:1 is actually 5%. Funny how the mind works - or doesn't!. Thank you all for making me stop to think about it! I Haven't actually mixed any reduced oil gas yet or I might've figured...

I would normally mix my gas at 20 to 1 for this engine. But because I recirculate crankcase discharge oil I mix 15:1.

There is such a thing as glow ignition for gasoline but I’ve never seen it.

No glow. The first thing I did is install the C&H spark ignition and I’ve been VERY happy with it.

I forgot this pic of the tubing bender I made for the intake pipe bends.

And here's the final result. This vid is the first runs. I hadn't got the mixture needles quite right yet but you'll get the idea. I could not have hoped for a better result. Thanks for staying with me to this point. Hope you enjoyed -

So to this point I addressed all the Gemini shortcomings but one: the waste oil discharge out the bottom of the engine. What a mess! Years ago, long before the manufacturers themselves started doing it, I ported this waste oil discharge straight to the carburetor induction manifold. Yes...

Of course with the carb sticking out the back the stock engine mount won't work so a set of standoffs is called for:

Almost done here:

Here you see the pressure tap off the top of the cam case. Very convenient location.

Here's a couple build pics.

Not sure where you got confused but there is only one pump - the one on the walbro. Originally I added a pump to the stock carburetor. But that's all history now.

With the intake manifold completed it was time to bend up some intake pipes. I had some 8mm O.D.x.8mm wall stainless pipe already so I prepared to bend it up. I'll say now that .5mm wall would be better but I didn't have any. The .8mm wrinkled just a little on the insides of the tighter bends...

The Gemini twin has an untapped pressure port already present on the on the upper part of the crankcase. I drilled it through, threaded and tapped for a nipple long ago - so I could inject preservative oil into the cam case to limit said corrosion. So I designed my new induction manifold to...

I knew I was really onto something. That Walbro tucks up behind the engine fantastically. Time to cut some metal!

I decided to make a wood model to check form and fit:

The first step is getting the proper Walbro for this engine. As I've said, the venturi on the stock carb is minuscule so I needed a Walbro set up for a tiny gas engine. Fortunately, Morris (I think in the video above) mentions that he's using a Walbro off of the RCGF 15cc engine. Bingo! I...