Distributor Questions

jme097

Random question regarding the cap and rotor...do you guys replace both the cap and rotor at the same time?  Just curious as to what everyones preference is. I am doing the plugs, cap and rotor this week before launch. 

skennelly

Under a normal cap replacement I'm doing the rotor too.

212rowboat

you're kinda silly not to.. it cheap - it's easy- especially if you're swapping caps anyway.

your points on the cap wear/corrode.. so does the button's tip... the gap starts to widen between those points... you're only closing it by 25% or so if you only do the cap.  a matter of fact, if it were me I'd be more interested in swapping the button rather than the cap if I had to choose just one, as it sees quite a bit more spark than the points (x8).  however, the plastic caps wearing because of spark, and because of heating to the temperature cycles present their own issues.  

A marine dizzy cap and button (properly vented) is what, $25?  it's something worth doing every season (or every other at a minimum)... It can be done while you wait for oil to drain, and it gives you an opportunity to inspect other things such as plug wires, boots, other sensor connections and wiring harnesses/connects as you're literally over the engine.  That hour maybe hour and a half are precious- if you encounter a no run situation either at the dock or on the water, you're gonna have that nagging in the back of your head and discover it's usually related to something you spotted during that pre-season hour-hour and a half inspecting things... you'll know where to find the CPS, the CKPS, injector harnesses, fuel pressure sensor port, IAC, TPS, if/where wires are crossed on a soft misfire situation, thermostat sensor/sender wiring condition/location, shift interrupt location and condition, condition of your throttle/shift cables... these things make you a better captain and a hero when you confidently turn to the admiral and say "yeah, dang starter slave solenoid needs a love tap" when you're trying to get rolling to outrun a storm.   

jme097

@212rowboat I appreciate the input. Do I really need to put OEM Mercury cap/rotor back on or will automotive version for the GM block do alright? I am in freshwater climate so I don't have the corrosion issues as salt. Just curious

randy56

@jme097 last spring I replaced mine, bought at NAPA auto parts. all good so far. Could not find OEM at the time. 

212rowboat

the marine cap is vented differently.... i can't really speak to functional differences, but i think the concept is disallowing condensation to build and to further protect against spark escaping.  i've never had an issue, but i swap mine every year and scoop it after every use- as in no floating at the dock... 

jme097

ahh I see what you're saying!