What type engine?

I thought I had a .049 Black Widow butupon close inspection it does not have a attached fuel tank. There is a hole in the bottom and what looks like a fuel nipple. Is this a .09 rather than a point .049 engine??.Also what fuel tank can I use with this tank and where can I buy it . Thanks!
Chuck

That is an .049 engine. It is a reed engine, like the tanked bee engine, but without the tank. You can run any external tank that is suitable. The fuel line is "small" with an ID of 1/16 inch, and not "medium" 3/32 fuel line.

What is your intended application?

Free flight often use a dosing syringe with the plunger removed, so the flight time can be carefully tuned.

Control line airplanes use a wedge tank typically, although other shapes have certainly been used, including square metal and plastic "clunk" tanks.

RC airplanes typically use a "clunk" tank.

Tether cars and RC cars typically use a square tank.

ALL applications can use a non-pressure bladder made from a party balloon, some hard tubing, and fuel line.

Pressure bladders can also be used but the original needle valve is not fine enough to adjust well. Either a fine NVA is required or some capillary tubing to restrict the fuel flow.

Hope this helps.

Phil