Trouble timing an emission (false/true bool) with variables

I'm having a little trouble making this work. No emission appears. I have tried using different functions for particle systems. And for some reason I cannot use particle emitter. Here is my code, someone please help! I'm trying to give the effect that a spaceship is shooting, but it needs to be timed so I can adjust it using the variables whenever.

 using UnityEngine;
 using System.Collections;
 
 public class simplenothingshoot : MonoBehaviour {
     
     public ParticleSystem leftgun;
     public ParticleSystem rightgun;
 
     public float ShootTimer = 0;
     public float ShootCooler = 0.9f;
     public float beamFlashCooler = 0.5f;
     public float beamFlashTimer = 0;
     public float KeyCooler = 1;
     public float KeyTimer = 0;
 
     // Use this for initialization
     void Start () {
             leftgun.enableEmission = false;
             rightgun.enableEmission = false;
     }
     
     // Update is called once per frame
     void Update () {
         
             if( KeyTimer > 0){
                    KeyTimer -= Time.deltaTime;    
                     }
         
                 if( KeyTimer < 0){    
                     KeyTimer = 0;    
                         }
         
         
             if( beamFlashTimer > 0){
                        beamFlashTimer -= Time.deltaTime;    
                     BeamFlashShow();
                         }
         
         if( beamFlashTimer < 0){
             beamFlashTimer = 0;    
                 }
         
         if(ShootTimer > 0){
             ShootTimer -= Time.deltaTime;
         }
         
         
         if( ShootTimer < 0){
             ShootTimer = 0;    
                 }
         
         if(KeyTimer == 0){
         if(Input.GetMouseButtonDown(0)){
         if( ShootTimer == 0){
         
             
                 
                 ShootTimer = ShootCooler;
                 KeyTimer = KeyCooler;
                     
         }
             
             if( beamFlashTimer  == 0 ){
                 BeamFlashShow();
                     beamFlashTimer = beamFlashCooler;
                 }
             }
             
         }
     }
     
     
     void BeamFlashShow(){
         
         
         if( beamFlashTimer > 0){
             
         
             leftgun.enableEmission = false;
             rightgun.enableEmission = false;
             
         }
         
         if( beamFlashTimer == beamFlashCooler){
             
             leftgun.enableEmission = true;
             rightgun.enableEmission = true;
             
         
         }
         
     }
 }