.049 starting?

It is possible to start with no prime using an electric starter, but very hard on the engine so don't do it. So yes, you need to prime the engine some way, some how.

How depends on which engine. On the rotary valved engines you can drip fuel into the intake, or turn the prop with your finger over the intake to suck fuel in (good idea to fill the fuel line this way anyhow). The sure starts have a choke tube so this also works on them. (or you can just drip some fuel down the tube if it is pointed upward) On the tanked engines the intake is not normally accessible. If, however, you could seal the intake to the firewall and run a tube through the firewall to an accessible location, you could do it. It would need to be around 1/4" ID or maybe a little more to avoid restricting the intake enough to hurt power.

Some of the cox cars had exhaust manifolds on them. There was usually a small hole to prime through. I think some of the factory mufflers had shutters you could open for priming or a little power boost if you were flying where the neighbors wouldn't complain. I've even seen that on some larger engines. (Some Enyas for example)

One way to prime is to hold your finger over the second vent on the tank and apply a little pressure with your fueling bulb or syringe. This will pressurize the tank and force fuel into the engine intake. This works on nearly anything, but it is easy to overdo it and end up with a hard-to-start flooded engine. Bladder tanks are normally done this way by default.

On Edit: To duct the exhaust, you need to use a non-SPI cylinder. Your exhaust manifold will prevent the SPI from drawing in fresh air at TDC.