I've owned a few other honda's, but this is my first Magna and I'm trying to figure out what the old owner had did to this bike (or at least why).
I picked up this bike about a month ago for 100 bucks. It ran...not good...but it ran. I've rode it a lot, but it has never had any power, idles rough, and feels like it misses through out the whole rpm range. I parked it this weekend and I'm going to go through the whole bike.
I pulled the plugs to see the condition and noticed that it had Non-resistor plugs so I put in a new set of stock resistor plugs and tried to start the bike. Wouldn't start. I put the old Non-resistor plugs back in...it fired back up and still ran real rough.
Now, the only reason I can think of to put in non-resistor plugs is because the bike had weak spark. I have checked the resistance on the primary side of the coils and the secondary side with the plug wires on and without the boots (removing the resistor in the boot). All are within the spec shown in the service manual. Hopefully the local Honda shop can test these coils under a load to tell if they are really any good.
I guess my biggest question is why there are resistors in the plug wires and honda recommends resistor plugs. Resistor plugs add up to 5000 ohms additional resistance per plug. From the manual...if secondary resistance with the plug caps on should be 21-28k ohms...adding resistor plugs could make that secondary resistance around 31-38K ohms. That seems extremely high to me.
Maybe I'm looking at this all wrong, but if anyone has any input...please feel free to set me straight.
I'll let others address the questions about spark plugs..
Since you recently procured the bike, was it sitting around a lot before you bought it??
If so, Run a can (follow dosing instructions) of SeaFoam through the gas tank... It may help to smooth out some of the issues you are having.. Some of the symptoms could be gummed up carbs... (Don't be afraid to double dose the 1st couple of tanks fulls... Check out the ALL Hail Seafoam thread if you have not done so already....
Actually, that was the first thing I did when I got the bike. I love Seafoam!!! I've used it in many different motors and fuel systems. It works wonders. I even ran a 50/50 batch through a fuel filter and straight into the carbs. It didn't really help out like it has on other bikes.
I am going to pull the carbs off and rebuild them anyway as well as replace a lot of the ignition system...just because the bike is so old and who knows what anyone else did to it years ago. I would rather go through it now than have to do it later when it dies on the side of the road.
Does anyone have an opinion about the secondary ignition system using non-resistor plugs?
Has anyone had these coils start going bad or do they just stop working?