Cook spaghetti in large pot of boiling salted water until just tender but still firm to the bite. Drain; rinse with cold water and drain well. Place spaghetti in large bowl; add 1 teaspoon sesame oil and toss to blend. Add carrot, bell pepper, jicama and spinach to bowl.
Whisk next 4 ingredients and remaining 3 teaspoons sesame oil in small bowl to blend. Season dressing with salt and pepper. Add dressing to salad and toss to combine.
Divide salad among bowls and serve.