Symptom's of a bad ignition coil, and wire's....98' M900?

[118811]

I have a 98' M900 that just had a full service in 6/12...belts, valve adj, etc.

Lately the bike is running rough & died 2x....once in very hot 25 min stop & go traffic ...Then another time for no apparent reason (not hot).

While it does start after these times.....it has become much rougher running all thru the RPM range.  As of last nite, it started sputtering around 5500 rpm's and wont climb any further.  Also when running at freeway speeds....it seems to miss a little..even maybe popping on occasion.....feels like it is flooding?

Could these be symptoms of bad plug wires  + coil's?

Thanks for all opinions!!!

[motoxmann]

could be bad coil/wire yes. I would first look at the sparkplugs themselves though. that sounds like spark blowout to me. which can be caused by a weak/failing coil, damaged plug wire, but most commonly simply from the sparkplug gap being too large and/or plugs being old.

grab a set of NGK dcpr8e plugs (#4339) and set the gap to 0.024"-0.025" (the gap is usually 0.035"ish out of the box, so definitely check and set the gaps), make sure to use a torque wrench to tighten them to 18-20ft/lbs, and see what happens

fyi I used to run champion plugs, and I replace them frequently cuz I'm just like that, and my last plug swap the champions had 500 miles on them and I switched to those ngk's and I immediately noticed an improvement in power, throttle response, and cruising smoothness. and the previous champion plugs were still dead on gap spec.

[118811]

Thanks Motoxmann!!

I'll get new plugs tomorrow

[ducatiz]

Check the plug caps.  They screw onto the wires.  If you have the black coils the wire screws into them as well.  They can get loose when serviced.  Unscrew the wire and cut off about 1/8th inch and reinstall. Make sure to lube the boots. 

[118811]

Again thanks for the tips!!
I will look at cil connections too
I hope to have my mechanic test my ignition coils
In the next couple of days.
I hate riding the bike in this condition.....wondering
When it will die next!!

[motoxmann]

x2 to the plug cap thing.

also I forgot to mention: the new sparkplugs will come with thick rounded tips on the wire end, which our bikes don't use. our bikes use the thin threaded tips. so grab a pair of pliers and just twist those metal tips on the ends of the sparkplugs to loosen them, then thread them the rest of the way off by hand.

if you try forcing a plug cap/boot onto a plug before removing this larger tip, it can and probably will damage the cap/boot

[118811]

I just removed the plugs...they are NGK D8EA & they were installed with the CAPS on...the wire set is not OEM though.
The plugs are brownish/grey in color......

Is it ok to go to the resistor type NGK DCPR8e plug?

[memper]

I was told here that those are good and "Ducati" approved. Get the 4339's

[118811]

went to the Ducati dealer today to get the NGK plugs.....I was quoted $4.99 yesterday over the phone.

Got there and the guy brings me two & gives me the price ...$39.98...19.99 each
DUCATI packaged NGK plugs VS NGK packaged plugs....
The plugs were identical except the DUCATI NGK plug had a solid end cap...the standard NGK plug had the open end...

Picture below.....cheap bastard I am went with the 4.99 NGK!!      (DUCATI plug below the NGK)

[motoxmann]

advance auto parts stocks ngk plugs, and they are $3.99 each iirc. just so you know lol

[118811]

Put the new plug's in this morning took a short ride bike still seems rough before 4k.

This afternoon took the bike by my mechanic's shop did a ignition diagnostic....everything is good.
Turns out theses black coils are the original...wires are about 6 years old.

I think I should get the Exactfit system from CA Cycle, includes coil, wire & plug's.
What would you guy's do?

[motoxmann]

What would you guy's do?

I would test the coils and wires according to the procedure recommended by ducati. my '00 M750 still has the original coils AND the original wires, and they still test perfectly within spec and operate flawlesly.

procedure and specs are probably available somewhere here on the site, or you can google it. if you can't find it anywhere I can post pics straight out of my manual on monday.

next step, I would simply clean out the carbs and set float levels to stock spec, and adjust the fuel enrichment screws. personally I think you have a fueling issue, not a spark issue. when ignition components start going out the engine will usually run best at lower rpms and lower throttle positions, and get rougher as rpms and/or throttle position INCREASE. ignition problems also tend to get worse as temps get hotter.

in your case, temps are getting colder, and it seems things are bad at lower rpms. my guess is that simply turning the fuel screws OUT (to richen it up) 0.5-1.0 turns and/or setting the float level to spec will solve your problem. if that helps at all even the littlest bit, I would also check the needle position, might need to raise the needles 1 notch

[118811]

Well.....bike seems be getting better.    

I went on a early morning (before traffic) spirited run.  Bike ran very good, going thru each gear up to 8.5-9K RPM smoothly.

RE carbs...I have FCR 41's on the bike & they have given me problems....  1x each year for the past 3 yrs....dirt/etc  have clogged the float and flooded the engine.
This just happened back in June of this year.  At that time they were pulled off and gone over, so they should be good now.  I also fitted an on/off fuel valve while I was in there.  The fuel pump was rebuilt also, using a genuine Mikuni rebuild kit during this repair.

Thanks again for all the suggestions, hopefully bike is good for awhile