Mid-range hesitation

[RaWarrior]

Upon poking around a bit, the Nology coils aren't the "twist-lock" style of the originals...they have an automotive style post connector.

The wires for the front ones are about 4x as long as they need to be...all the excess is coiled up and shoved in there behind the plastic electronics panel behind the left scoop. Checked all the wires to the coils and none were loose or showed signs of corrosion. Still, I removed them and used a bit of dielectric. Also, the coils for cylinders 1,2,3 are coils marked just as "nology", while the #4 coil is slightly different(lil bigger) and says "nology Pro-Fire". Think that could be causing this odd problem?

Also, I discovered that #2 cylinder's headpipe had come out of the holeshot slip-on...noticed when I started it over grass and saw it all blowing back under the motor. Dunno how long it's been like that, but now that I fixed it the bike is somewhat quieter...never noticed it was louder. Could a lack of back-pressure cause issues?

I'm going to borrow a 3/4" plug socket from work to pull all the plugs and compare them side by side to see if I can garner any clues. Could it have been #2 running essentially a straight pipe, or #4 with a different coil? Tune in tomorrow for the exciting conclusion!

 

[gamorg02]

i bet all those could contribute

 

[tugla]

the pipe out for sure would have some impact on it. let us know after your ride today

 

[RaWarrior]

OK....took it for a ride after fixing the open exhaust. Quieter, maybe a tad smoother, but the lag was still noticeable. Also...since moving my clips I hit low fuel at only 105 miles....I usually get 120-125, and that was all conservative highway riding.

Pulled the plugs. First, they are NGK Iridium's, DPR8EIX-9. They don't look a whole lot different than before moving the clips, at least subjectively. All four look pretty much the same. Left to right.....cylinders 1-4




However, what I did notice on #3's plug is there's a big splotch of what appears to be metal on the insulator, right around the electrode. It's really hard, and I couldn't scrape it off. Almost appears that a bit of metal melted off some other part of the plug and "splatted" onto the electrode. It's definitely close enough to be arcing off the electrode(possibly grounding the spark, or resulting in a spark so tiny the cylinder doesn't fire?)




I'm going to get a set of stock NGK's and toss them in.

 

[RaWarrior]

OK....got a set of the stock NGK's and went for a ride. Initially it seemed to have solved the issue...ran perfect for like 50 miles, mixed highway and back roads. Then I stopped for a while, and on the way back the misfire was back same as always. :bang head:. It definitely feels like one cylinder is firing intermittently. However since the problem is intermittent, and it idles fine/top end is fine, it doesn't misfire enough to show it on one of the plugs.

I guess really the only thing left to try is stock coils/wires. My wires have the automotive style "post" connector on the coil end, so I'd either have to cut the connector off or get stock wires.

But what still bothers me is if it's a coil issue, why would opening the boost valves instantly eliminate the problem? Or does that just cover it up? Arrrgh.....

Now checking the plugs again, they all look essentially the same. Still clean white electrode, but a coating of grayish ashy stuff only on the ground strap of the plug. The picture is a bit blurry, but getting a clear picture of a plug is kind of difficult. The second is what the p/o left me under the seat. One of the factory yellow coil connectors was cut off, but the other three are still there and it appears he cut the connector off the stock coil, then just spliced in two spade connector wires to the nology coils. Also, the one "pro-fire" coil is marked as "use on 3.0 ohm systems". Is that right? Wait...looking around I see in a few places that the Vmax system should read about .8 ohms....

One more thing: I saw on another thread here that from the factory, the front two coils are "swapped", as in the left side coil fires the right cylinder, and the right fires the left, and if they are reversed the bike may run crappy. The front still has the stock yellow connectors coming out of the harness...there's a longer one(presumably originally to the right side) and a shorter one(for the left). However, the shorter one goes to the left coil, which is wired to the left cylinder, and the right coil fires the right cylinder. Is that opposite of what it should be? There's plenty of slack, should I try reversing the connectors?

And how the hell do you get at the front coils? They're absolutely buried in there.

 

[RaWarrior]

Update time...

I looked into the COP conversion. I had initially wrote it off thinking it was an expensive/complex conversion, but it was actually surprisingly cheap($30 shipped for 4 sticks and harness off ebay), and it took maybe an hour to splice in the harness and get everything tucked away neat. Knock on wood but so far I have yet to feel a misfire, and as others noted it seems to be just a bit more responsive and start a bit easier. And the connectors are counter-intuitive...the coil connector that is more on the right side is for the left cylinder and vice versa. When I first went to start it it backfired and ran like crap, but after switching the front connectors it fired right up and ran great. Probably going to be a 4-500 mile day tomorrow, so they'll be put to the test.

The t-boost (only when set to 3k) seems to work intermittently now. At 6k it's always fine, but at 3k it feels like it only sometimes activates. Maybe I'm just not noticing, who knows. I rarely ever use the 3k setting anyway.

However, after moving the needles 1 clip out, I lost about 5mpg, or about 15 fewer miles to reserve. Used to get 120-125 to low fuel, now I get 105-110 over four tanks, so it's definitely a trend. Subjectively the bike runs exactly the same as before moving the needles, except it's consistently using a lot more gas. The setup is 3rd clip from the pointy end on the stage 1 needles(used to be 4th), and 3 turns out on the mixture screw. Temp is never an issue(wasn't before either). I'll go pull a plug and try to get a picture.

 

[Redbone]

Glad your getting it sorted Ryan, I'm happy with my cops mod as well. :thumbs up:

 

[tugla]

awesome good job man glad to hear you got her running.

 

[RaWarrior]

559 miles(in about 12 hours) of very "enthusiastic" riding later and the bike ran fantastic all day with the COPs. High speeds on the highway, frequent roll-ons between 90-120 or so, lots of two-lane road passing, ect. So it seems that either the coils or wires were at fault here, despite both being replaced between the 08-09 season by the p/o.

Before the trip I moved the needles back to the 4th clip out, where I originally found them. The mileage returned to the 40-42 range....but get this. I still got 40mpg with almost exclusively high speed hard riding with several extended v-boost moments. Being heavy handed with the throttle seemed to have no effect on mileage. Then on the ride home at a steady 75mph cruise, I got 41. On the other hand my friend with the M109 usually gets about 45, and he was only getting 33-35 during the same riding. His mileage took a huge hit, mine was virtually unchanged.

Also odd...I pulled a plug the next day and it still looks brand new. Insulator was still bright clean white....no deposits whatsoever. There was maybe a bit of dark gray dust on the electrode, but otherwise clean. Tough to make a call lean or rich....temps were in the high 80's all day, the temp gauge never budged past it's usual hangout 1/3-1/2 way up the scale even at 100mph up an 8% grade, so it doesn't seem to be too hot. Always run regular 87 gas. So the hotter spark of the COP's seems to "burn off" deposits and keep things cleaner? I don't know. Never seen a plug run for 8 hours still look brand new out of the box before.

 

[tugla]

nice job man, so you picked up COP's from the R1, i'll have to go back up and read your post. where you get them off of flea bay??? might be time for my 97 to get the same treatment.

 

[vmax626]

I've got this little problem with my '97 that kind of comes and goes on a pretty random basis.

At highway speeds(say 55 and up), sometimes the throttle acts like it hits a "dead spot" when I go to roll on the gas. To put it another way, slight increases in throttle have virtually no effect. If I continue to slowly roll on, by maybe half-2/3 throttle all of a sudden it takes off and runs fine. Getting the RPMs up doesn't seem to make much of a difference, I can be cruising at 90 and get the same "lag". Past 6k with vboost, it seems to stop, and if I switch the t-boost to 3k(to open the valves), that usually clears it up. When the "lag" occurs, it almost feels like one cylinder is not firing.

The p/o installed a Stage 1 kit, and a K&N filter. Stock headers, holeshot s/o's. Nology coils, NGK wires/caps, and NGK Iridium plugs.

I've tried both the peashooter and shotgun...neither seemed to make much of a difference. However, when I drained the bowls a relatively large amount of water came out of one carb bowl...the other 3 were fine. It was the right-rear carb. Checking the plugs, they all look the same. To my eye they seemed maybe a teensy bit lean, there was just a "hint" of tan color on the insulator. Otherwise the bike runs awesome. Smooth steady idle, no starting problems, loads of power. Never overheats, or even comes close to the red zone on the temp. With the fan running it NEVER goes past half way on the temp gauge.

I've tried using sea-foam, the blue sta-bil, and other fuel additives with fill-ups. Since the problem is intermittent, it's difficult to tell if a period with no lag is from the additive or just chance. Note: all gas around here is E10. The marina where I work recently got ethanol-free gas, so I'll try running that to see if it makes a difference.

Since the shotgun, it seems to maybe have gotten better.....subjectively it happens less often and the "lag" isn't as pronounced.

Eagle recently had his carbs redone, and mentioned that he had a "stumble" between 4-6k....similar to my problem. He said that adding one washer to the needles solved it. I'm not so good with CV type carbs, so correct me if I'm wrong, but adding a washer would "lift" the needle a bit more, and make the bike a bit richer? That could explain the lean looking plugs, and why activating v-boost clears the issue up. A lean midrange? Last question: where would I get washers for the needles to try this?

I used to have the exact same problem, but I traded Fargo those needles for some stock ones and shimmed them and the bike ran great through the whole throttle cycle and now I`m playing with the muscle kit and Marks header system:rofl_200:.
<<Dave>>unk:

 

[RaWarrior]

Just to add "closure" to this topic for any future readers who stumble across this... pretty sure I finally figured this out....


The problem wasn't in the carbs at all. Turned out the intermittent, random misfire was from low voltage to the tune of about 12.3 volts at cruising speed. The misfire always seemed to occur when "rolling on" the throttle, or going up hills. This would raise cylinder pressure, requiring more energy to spark. A marginal or weak spark (from low voltage at the coils) might spark okay cruising, but under high cylinder pressure the spark fails to jump, resulting in the random misfire.
After replacing both the r/r (MOSFET style off a Ninja ZX10), and the stator(replacement from Rick's Electrics) and wiring the new r/r directly to the battery, I have 13v hot idle(highbeam and fan on), and 14.4 at anything above about 1500 RPM. The misfire has never returned after doing this. It cranks faster, and starts easier also.

Another note...the stator tested fine according to the manual's specs, and worked fine when COLD....14.4 volts with the old stator and new r/r. However, once the motor warmed up, it was down to about 12.2 at idle, and a peak of about 13 revved up. Even hot, it still tested OK ohm wise. However, two of the stator's poles were tinged black and looked burnt. As I said, replacing the stator cured the voltage problem, so fading voltage as the motor warms is almost certain to be an intermittently shorting stator.

 

[gamorg02]

glad u got it ryan. similar to my xr250 issue. bad ground, all sorts of random stuff. chasing carbs for 3 weeks.

 

[tugla]

ryan, got me thinking i have similar voltage at idle and a similar issue at the same rpm. how much was your r/r and stator?

 

[hexec]

Just to add "closure" to this topic for any future readers who stumble across this... pretty sure I finally figured this out....


The problem wasn't in the carbs at all. Turned out the intermittent, random misfire was from low voltage to the tune of about 12.3 volts at cruising speed. The misfire always seemed to occur when "rolling on" the throttle, or going up hills. This would raise cylinder pressure, requiring more energy to spark. A marginal or weak spark (from low voltage at the coils) might spark okay cruising, but under high cylinder pressure the spark fails to jump, resulting in the random misfire.
After replacing both the r/r (MOSFET style off a Ninja ZX10), and the stator(replacement from Rick's Electrics) and wiring the new r/r directly to the battery, I have 13v hot idle(highbeam and fan on), and 14.4 at anything above about 1500 RPM. The misfire has never returned after doing this. It cranks faster, and starts easier also.

Another note...the stator tested fine according to the manual's specs, and worked fine when COLD....14.4 volts with the old stator and new r/r. However, once the motor warmed up, it was down to about 12.2 at idle, and a peak of about 13 revved up. Even hot, it still tested OK ohm wise. However, two of the stator's poles were tinged black and looked burnt. As I said, replacing the stator cured the voltage problem, so fading voltage as the motor warms is almost certain to be an intermittently shorting stator.

A couple posts back you wrote that the COP mod solved your problem. Did you have more than 1 problem?

 

[RaWarrior]

Time for one last update, and now I mean I solved it. Actually did this weeks ago, but kind of forgot about this thread.

I was fooled, twice, by "false positives". The misfire was very intermittent and random as I said initially, sometimes not appearing for days or weeks, other times coming and going several times on one ride, so it was tough to tell whether a change actually solved the problem, or it just wasn't "acting up" at the moment.

That was the case with the COPs. Initially it seemed to solve it, but it came back a few days later (did seem less prevalent though).

Also the case with the R/R and stator, except this one really threw me through a loop....was perfect for like 2 weeks and several long trips. Then one day on the highway it suddenly came back. ARRRRRRRGH!:bang head: I was about ready to go insane from this needling little problem that I couldn't solve.

Finally, I sought out some expert help. I talked to Sean about it several times, I called Dynojet and actually talked to the "head carb engineer" about this. He and Sean both essentially said it sounded like it was too rich in the midrange and "loading up", why it manifested under constant, steady throttle. DJ recommended that I go back to the stock (larger) PAJ2, which would let in more air and lean it out. I didn't have the stock jets. He said next best would be to drop all the needles one clip, from 3rd to 2nd from flat end. So I did that, and now there's a marked improvement overall in the bike. The midrange feels stronger and more responsive, and the misfire has not occurred in well over a month's worth of riding, so I'm hesitantly saying it's been kicked.

Tugla...the r/r was $40 if I remember, came off a wrecked ZX10. The stator was by Rick's Electrics, and was like $120 or so shipped. While the low voltage was definitely a problem, I don't think it was "the" problem. Or maybe it was a combination of all these things, who knows?

 

[hexec]

Thanks for the explanation. Glad to hear you finally solved your problem.