Spices - You can become wealthy as HELL, and your modern day clothes can easily make you seem like some foreign merchant, so can get you people interested. You DO need to sell those spices fast, however, else you WILL get robbed
Motorcycle - As others have said, you can get it to run on grain alcohol once out of gas, but that’s not the real prize with it. The real prize is using your new found wealth to get smiths to make more engines, using that as a blueprint, and essentially kick starting the industrial revolution. Mind, this IS going to be used for war, so prepare to become a war mongul
Issue is that multiple countries have systems where it’s, “They launched nukes? We’ll launch all our nukes”
The mitigation is basically, “We will wipe you off the map if we think even ONE nuke is coming at us,” and this has nearly happened several times, only stopped because the system has a human at the final step, and humans when realizing they could end the world seem to hesitate