coil question

So the weater is warming up and I trying to get the bike back in riding condition. When I fired her up I noticed a lack in power and that one of my pipes did seem to be warming up. At first I thought I was a valve issue, the i notice my third pipe was also not getting warm. I took it her into my machanic and he said it was most likey a coil issue. My questions are?

1. Is it possible that it is a coil.
2. How hard are coils to replace
3. What is a resonable price on a new coil.
4. Is it something that I could replace.

 

Hello xjbodoss,

I just recently replaced the coils on my maxim. I started getting really bad hesitation from take off, and it idled for crap. The wires had become so dry rotten that electricity was arcing all over the place. I was only getting spark to 2 cylinders.


To answer your questions

1) If it coughs and stutters from a standstill, idles for crap, and seems to run smoother at cruising speeds, it very well could be a coil.
2) Coils take 15 minutes to replace
3) New Yamaha coils are really expensive, about 140 per coil I think, and aftermarket replacements don't really fit in the narrow channel of the gas tank. I've heard there is a way around this, I'm not sure though. Check ebay. I got a near perfect set of used oem coils for 30 bucks. There are usually sets for sale.

Another option is if you have rotten wires but good coils, you can remove the old wires and replace them with newer heavy duty wires. It takes some work and a steady hand, but seemed do-able. I have not tried this. It could be the most cost effective method.

4) Yes, you can replace the coils. It is a very easy, hard to screw up procedure.

Take off your seat, there is one bolt holding the take to the frame, remove it. Being very mindful of the gas line (as in, do not pull it off the bike, spewing gas everywhere), wiggle the tank backwards until the coils are exposed. Unbolt the coils, there are 2 bolts, and unclip the wires. Pay attention to which wires go to which cylinder, draw a picture if you need to. Remove the old coils and install the new ones, making sure the wires from the new coils are going to the correct cylinders. The Installation is the reverse of removal. Put your tank and seat back on and go for a ride.


Unfortunately, it has been below freezing in Ohio for the last few weeks, and I haven't gotten a chance to test my new coils on the road. The bike starts right up and idles fine in the garage. I can't wait to get it out on the road though.

 

Had the same problem last week on my '83 Midnight. #1 wasn't firing (cold pipe), but the rest were. Told myself to look for cheap first. Changed the spark plug in #1 and cured the problem. Might want to look there first.