problems scripting a fly?

ok so i make a Marvel game and for Human Torch from the Fantastic 4 i wanted a "Fire Fly" it works perfectly except for the fact that when i stop flying i die. this is very disappointing cause i have tried to fix it several times and i just cant. this is the clip of script that i have that i made to the original fly i have to make the fire bellow...

function Fly()

    if Flying and Player and Torso and Humanoid and Humanoid.Health > 0 then

        local Momentum = Vector3.new(0, 0, 0)
        local LastMomentum = Vector3.new(0, 0, 0)
        local LastTilt = 0
        local CurrentSpeed = Speed.MaxSpeed
        local Inertia = (1 - (Speed.CurrentSpeed / CurrentSpeed))
        fire=Instance.new("Fire")
        fire.Heat=0
        fire.Size=10
        fire.Parent=script.Parent.Parent["Left Leg"]
        fire2=Instance.new("Fire")
        fire2.Heat=0
        fire2.Size=10
        fire2.Parent=script.Parent.Parent["Right Leg"]
        fire3=Instance.new("Fire")
        fire3.Heat=0
        fire3.Size=10
        fire3.Parent=script.Parent.Parent["Left Arm"]
        fire4=Instance.new("Fire")
        fire4.Heat=0
        fire4.Size=10
        fire4.Parent=script.Parent.Parent["Right Arm"]
        fire5=Instance.new("Fire")
        fire5.Heat=0
        fire5.Size=10
        fire5.Parent=script.Parent.Parent.Torso
        fire6=Instance.new("Fire")
        fire6.Heat=0
        fire6.Size=10
        fire6.Parent=script.Parent.Parent.Head
        BodyVelocity.maxForce = Vector3.new(1, 1, 1) * (10 ^ 6) 

        BodyGyro.maxTorque = Vector3.new(BodyGyro.P, BodyGyro.P, BodyGyro.P)
        BodyGyro.cframe = Torso.CFrame

        while Flying and Torso and Humanoid and Humanoid.Health > 0 do

            if CurrentSpeed ~= Speed.MaxSpeed then
                CurrentSpeed = Speed.MaxSpeed
                Inertia = (1 - (Speed.CurrentSpeed / CurrentSpeed))
            end

            local Direction = CurrentCamera.CoordinateFrame:vectorToWorldSpace(Vector3.new(Controls.Left.Number + Controls.Right.Number, math.abs(Controls.Forward.Number) * 0.2, Controls.Forward.Number + Controls.Backward.Number))
            local Movement = Direction * Speed.CurrentSpeed

            Momentum = (Momentum * Inertia) + Movement

            local TotalMomentum = Momentum.magnitude

            if TotalMomentum > CurrentSpeed then
                TotalMomentum = CurrentSpeed
            end

            local Tilt = ((Momentum * Vector3.new(1, 0, 1)).unit:Cross(((LastMomentum * Vector3.new(1, 0, 1)).unit))).y
            local StringTilt = tostring(Tilt)

            if StringTilt == "-1.#IND" or StringTilt == "1.#IND" or Tilt == math.huge or Tilt == -math.huge or StringTilt == tostring(0 / 0) then
                Tilt = 0
            end

            local AbsoluteTilt = math.abs(Tilt)

            if AbsoluteTilt > 0.06 or AbsoluteTilt < 0.0001 then
                if math.abs(LastTilt) > 0.0001 then
                    Tilt = (LastTilt * 0.9)
                else
                    Tilt = 0
                end
            else
                Tilt = ((LastTilt * 0.77) + (Tilt * 0.25))
            end

            LastTilt = Tilt

            if TotalMomentum < 0.5 then
                Momentum = Vector3.new(0, 0, 0)
                TotalMomentum = 0
                BodyGyro.cframe = CurrentCamera.CoordinateFrame
            else
                BodyGyro.cframe = CFrame.new(Vector3.new(0, 0, 0), Momentum) * CFrame.Angles(0, 0, (Tilt * -20)) * CFrame.Angles((math.pi * -0.5 * (TotalMomentum / CurrentSpeed)), 0, 0)
            end

            BodyVelocity.velocity = Momentum
            LastMomentum = Momentum
            Wait(FlyRate)

        end

        BodyVelocity.maxForce = Vector3.new(0, 0, 0)
        BodyPosition.maxForce = Vector3.new(0, 0, 0)
        BodyGyro.maxTorque = Vector3.new(0, 0, 0)

    end
end

function StopFlying()
    Flying = false
    BodyVelocity.maxForce = Vector3.new(0, 0, 0)
    BodyPosition.maxForce = Vector3.new(0, 0, 0)
    BodyGyro.maxTorque = Vector3.new(0, 0, 0)
    script.Parent.Parent["Left Leg"]:ClearAllChildren()
    script.Parent.Parent["Right Leg"]:ClearAllChildren()
    script.Parent.Parent["Left Arm"]:ClearAllChildren()
    script.Parent.Parent["Right Arm"]:ClearAllChildren()
    script.Parent.Parent.Torso:ClearAllChildren()
    script.Parent.Parent.Head:ClearAllChildren()
end

ive also tried making the fire greenish for my Dr. Strange but i dont know how to change the color!! D:

if you have time can you also tell me how to use this with particles ... cause i cant figure it out trying to use my own decals ... i just get the classic particle decal.

thank you for reading this and thank you for any help i may receive

~FinickOdre123