How big is it? It looks like it has a push/squeeze bit so it can be removed (the red bits). Breather pipe?
Thanks for your response. The overall length is 7.5 cm; the larger diameter is 3.5 cm and the smaller diameter is 2.0 cm. Where the diameter "funnels in " to the smaller diameter, there appears to be some residue of sealant. Could it be a crankcase breather of some sort?
Could be. It's open at both ends with a cross to keep the narrow end open. I was thinking of the hose that connects to the throttle body, near the bulkhead in the right as you look at the engine. But I think that hose is for the brake servo, so you might notice if that was disconnected.