#1 PLUG WIRE SHORTING, SHOCKING, BUT RUNS FINE, what now?

I hope it is a simple wire replacement. Any ideas?

 

Re: #1 PLUG WIRE SHORTING, SHOCKING, BUT RUNS FINE, what now

I saw in another post a suggestion to remove the plug socket --mine screw off-- and cut about 1/4 inch off the plug wire and re-attach the socket. They also mentioned a kit that would allow you to cut the line about 1 inch from the coil and splice in a new wire. Finally, apparently a new wire can be connected directly to the coil but no instructions were given. I'd contact Chacal and see what he has.

 

Re: #1 PLUG WIRE SHORTING, SHOCKING, BUT RUNS FINE, what now

Are you sure it's the wire and not the boots that connect to the plugs? These are readily available at any cycle shop and are easy to replace.

 

Thanks. I will check that out. I have the bike runnig fine even though it shorts.

 

Be careful buying them "at any cycle shop."

The 550s use 10K Ohm plug caps. Don't add another variable to your tuning woes.

Do as suggested above: unscrew the plug cap from the end of the wire; lop about 1/4"~3/8" off the end of the wire and screw the cap back on. There is a threaded spike inside the cap that screws into the center of the wire. Don't overtighten and strip it.

While the cap is off, look inside the "business end" where the spark plug goes. The resistor core has screwdriver slots on either side of where the plug goes in; gently ensure the core hasn't come loose (common.)

Actually replacing a plug wire without splicing involves grinding away the body of the coil to access the junction, soldering a new wire in place and then filling the damage with epoxy. I'd replace the coil myself if truly necessary, which I doubt.

Oh, and I've been meaning to let you in on something: if that's the color scheme your bike came in, and your "shorty" VIN is higher than 4U8-100101, you have a 1983, not an '82. (Yes it was made in '82, my '83 was made in '82 also, May. VIN 100960) I'd actually be interested in your serial number and manufacture date; I don't believe that Yamaha made more than about 900 or so 1983 model 550 Secas, all in '82, and I've yet to have that disproven.

 

Re: #1 PLUG WIRE SHORTING, SHOCKING, BUT RUNS FINE, what now

Oops.. Good catch Fitz. I forgot that some of the plug caps have resistors.

 

They pretty much all do, except the 650/750s use a 5K Ohm cap IIRC.

 

Today I lost all power in the middle of a yard sale binge. I guess that would be the last of that coil. Thaqt's what I get for not fixing the short before the damage. I now need to replace the coil on that side only, most probably. Hopefully someone local might have one so I won't have to wait on the USPS. Which coils would be compatible?

 

Ru sure it's the coil? Have you swapped coils to test your theory?

See also

http://www.xjbikes.com/Forums/viewtopic ... coils.html

 

It's not the coil if you only lost fire on one cylinder; or at least highly doubtful.

The coil that fires #1 also fires #4; #2 and #3 are fired from the other one.

When the coil fires, it fires both of its plugs every time, even though one cylinder is on the exhaust stroke. (This is known as a "wasted spark" system.)

These coils are pretty proprietary; it's not something that you're likely to find locally unless you live near a motorcycle junk yard.

DID YOU TAKE THE PLUG CAP off the wire yet? How about the resistor core? The rubber boots just slide off the cap, slip the rubber parts off and inspect the cap.

Check the connections to the coils. Check the wiring from the ignition pickups, especially where it comes out of the back of the case and snakes around before disappearing next to the alternator.

Take the tank off and inspect everything carefully. A "failing" coil doesn't cause the symptoms you were initially describing; something else is going on. CAREFULLY inspect the #1 plug wire along its entire length. Be sure the wire isn't cut or split or damaged internally (you would "feel" that.)

 

Fitz and crew, I have ordered a coil just in case and created a new topic because of the change in headlines. This should be a learning expereince to avoid and I want to get the word out. I will start a thourough inspection and get back. Sorry about the mess. Link to the new topic http://www.xjbikes.com/Forums/viewtopic/t=38102.html

 

So exactly what IS the failure? Results of diagnosis, as above?

Do I have your email address already? If so, do you need the "ignition" fault diagnostic from the factory book?

I suspect conclusions are being leapt to.

 

Yes, you may be correct. I will propably be alright with the live wire. I just needed to cover the cylinoid a little better, just taped it up for now. And I will get a boot for the negative terminal on the battery (it was up against the frame). I have the CD on my bike and will be us studing the ignition system diagnostics. Appreciaten.