Hello,<br /><br />I have twin 1989 Johnson 150's, run great...I noticed a couple of small cracks in the throttle cable, (plastic housing/insulation). The cracks are located just before the engine cowling. It appears rust is beginning to exit through the small cracks. What is the life span of throttle cables? (I believe these cables were installed around 1991 and still working)The other cables appear fine.<br /><br /> The fuel lines are also 1991, No obvious defects. Due to their age, should they be replaced? Thanks Homey.