Still not up to snuff.

[Dick Wells]

Got my new wires and plugs from BajaRon, and they're great (see the thread on new plug-wire source), but, a few more miles of riding shows that there are still some issues. The major miss-fire issue seems to be gone, but, at random intervals, there'll be a skip for a revolution or two, and sometimes a phft-phft for a couple of revs at neutral throttle. Now, it will rev right through this, and really scoot, if you roll the throttle on by. I mean, the thing seems to have all kinds of power, just wants to sputter a little, from time to time. Just enough of a bother to make me hesitant about wanting to take it out of town for a longer ride.
Does this sound like an O2 sensor issue? Seems like if it was an ignition module thing, that the added cylinder pressure, etc, would show itself by not allowing me to accelerate on by and produce smooth power at higher rpm's.
Sure wish I was close to Cowtown!nojoke
Thoughts from the experts?

 

[BajaRon]

Got my new wires and plugs from BajaRon, and they're great (see the thread on new plug-wire source), but, a few more miles of riding shows that there are still some issues. The major miss-fire issue seems to be gone, but, at random intervals, there'll be a skip for a revolution or two, and sometimes a phft-phft for a couple of revs at neutral throttle. Now, it will rev right through this, and really scoot, if you roll the throttle on by. I mean, the thing seems to have all kinds of power, just wants to sputter a little, from time to time. Just enough of a bother to make me hesitant about wanting to take it out of town for a longer ride.
Does this sound like an O2 sensor issue? Seems like if it was an ignition module thing, that the added cylinder pressure, etc, would show itself by not allowing me to accelerate on by and produce smooth power at higher rpm's.
Sure wish I was close to Cowtown!nojoke
Thoughts from the experts?

Is your Spyder stock?

 

[boborgera]

Got my new wires and plugs from BajaRon, and they're great (see the thread on new plug-wire source), but, a few more miles of riding shows that there are still some issues. The major miss-fire issue seems to be gone, but, at random intervals, there'll be a skip for a revolution or two, and sometimes a phft-phft for a couple of revs at neutral throttle. Now, it will rev right through this, and really scoot, if you roll the throttle on by. I mean, the thing seems to have all kinds of power, just wants to sputter a little, from time to time. Just enough of a bother to make me hesitant about wanting to take it out of town for a longer ride.
Does this sound like an O2 sensor issue? Seems like if it was an ignition module thing, that the added cylinder pressure, etc, would show itself by not allowing me to accelerate on by and produce smooth power at higher rpm's.
Sure wish I was close to Cowtown!nojoke
Thoughts from the experts?

Sounds like a spark plug wire, But you just put new ones in,
This might sound simple but are you sure you tighten down the spark plugs all the way:dontknow:

 

[AMTJIM]

Without being there to observe this live, v-twins and sport v-twin engines idle different than 4 cylinder machines brrrrrrrrrrrr. They do have a little inconsistency at idle and seem to miss,spit and sneeze a little. You may be over examing this since there was a previous problem, sounds like it's running normal. It gets up and goes like it should.

 

[Dick Wells]

Ron: Yes, the engine is stock.
The plug box is very explicit about tightening a new plug one/half turn, after the washer/gasket meets the head, so, yes, they're tight.
No, it's not running normal, for a V-twin, or a single, or any engine, for that matter. It idles just fine, most of the time, and any skips are a (very) momentary drop-out of one, or two firing impulses. You can actually hear it missing. It's always had what BRP has called a "driveability" issue, of surging, loping, bucking, which was partially taken care of, over a year ago, by a re-flash, but still there. However, that's not a miss-fire, and is quite liveable. This miss is just that, a miss-fire, but, since it will charge right on by, and accelerate like gang-busters, I can't help but wonder if there's an instant of no fuel, or lean fuel, that isn't there to fire when the spark is. That's why I'm wondering about the O-sensor, or the PCM. Dang electronics, anyway!
My MIL had a Toyota, way back when. A four-cylinder. Ran terrible for many months, after having been purchased brand-new. Many trips to the dealer proved of no help. They changed plugs, wires, the whole distributer, many times, and the darn thing would buck and skip and take on something awful, while you pushed on through with the throttle, and then, after it got up to higher RPM's, would take off and run. In other words, you had beat the snot out of it, to go anywhere. Finally, one week-end, she brought it to me, and I tore into it with determination. Took the carb apart, and checked the main jet, against the specified one, and "voila", the thing was a couple of sizes too small. Dealer didn't have a correct one, so I had the specks, and drilled it out to the right diameter, and the car went on (running just fine) for several years, to be traded in Oregon by my Sister-In-Law. Now, if the Spyder only had a carburator, and a set of points and condensor, I could (maybe) fix it, and change ignition parts every few weeks, like we used to in the good old days.

 

[BajaRon]

Ron: Yes, the engine is stock.
The plug box is very explicit about tightening a new plug one/half turn, after the washer/gasket meets the head, so, yes, they're tight.
No, it's not running normal, for a V-twin, or a single, or any engine, for that matter. It idles just fine, most of the time, and any skips are a (very) momentary drop-out of one, or two firing impulses. You can actually hear it missing. It's always had what BRP has called a "driveability" issue, of surging, loping, bucking, which was partially taken care of, over a year ago, by a re-flash, but still there. However, that's not a miss-fire, and is quite liveable. This miss is just that, a miss-fire, but, since it will charge right on by, and accelerate like gang-busters, I can't help but wonder if there's an instant of no fuel, or lean fuel, that isn't there to fire when the spark is. That's why I'm wondering about the O-sensor, or the PCM. Dang electronics, anyway!
My MIL had a Toyota, way back when. A four-cylinder. Ran terrible for many months, after having been purchased brand-new. Many trips to the dealer proved of no help. They changed plugs, wires, the whole distributer, many times, and the darn thing would buck and skip and take on something awful, while you pushed on through with the throttle, and then, after it got up to higher RPM's, would take off and run. In other words, you had beat the snot out of it, to go anywhere. Finally, one week-end, she brought it to me, and I tore into it with determination. Took the carb apart, and checked the main jet, against the specified one, and "voila", the thing was a couple of sizes too small. Dealer didn't have a correct one, so I had the specks, and drilled it out to the right diameter, and the car went on (running just fine) for several years, to be traded in Oregon by my Sister-In-Law. Now, if the Spyder only had a carburator, and a set of points and condensor, I could (maybe) fix it, and change ignition parts every few weeks, like we used to in the good old days.

Thare are a lot of questions I could ask but it doesn't sound like a simple fix. What I mean is, the fix might be simple enough (like the carb on your Toyota), it's the diagnosis that may be difficult.

I have an inductive timing light that works real well to tell me if a plug is miss firing. Like you say, the plug may be firing just fine but if there is not an ignitable fuel charge in the cylinder it will act the same as if the plug were not firing. Probably a too lean mix.

I assume it is only under load that you get this sputter. You can't run the engine to a certain RPM with no load and duplicate the problem? If only under load and only during acceleration through a certain RPM range it sure sounds like fuel. But we're only guessing. And if it is fuel you still have to find the culprit. The O2 sensor is a good place to look.

Putting it on BUDS might give you more information.

 

[NancysToy]

Ron has already provided a lot of good thoughts. I can add very little. Determining whether this "miss" is under load or no,t is an important factor...at least it can get you looking in the right direction. If the ECM failed before, and had to be reflashed, it may be on its way out again...or it was never completely cured. Another possibility is that a plug that gets too hot can misfire. This often does not last long, as the failed charge and the incoming mixture cools the combustion chamber and plug enough to make it fire again. Be sure that you have used the mandatory heat sink compound on the plugs. I would also try to determine if this is actually an afterfire miss, in the exhaust. Lean mixtures, exhaust leaks, and extra fuel in the exhaust due to misfire, can all cause a little firing in the muffler, that sounds and acts very much like an ignition or fuel system related misfire. Y-gaskets that are beginning to fail could cause this easily. Be sure and snug up the exhaust clamps at every oil change.

This problem may not be important, and may not be hurting performance, but it is getting under your skin, so it is worth chasing and finding. I wish you the best of luck...perhaps with the help of a talented technician and BUDS or a dyno. Like you, I miss carburetors, points and condensors sometimes. I certainly do sympathize.

 

[AMTJIM]

Yeah, sounds shop worthy or self investigation. The v-twin sneeze is not a full miss of a 4 cycle run, just a little offset hic-up but fires each time. One, maybe both cylinders, are going through all four cycles and randomly either not sparking or there's no fuel at the time of spark, maybe both? A little tricky to TS, could be a weak injector if it's fuel that's missing. A weak or faulty FI solenoid, maybe the driving transistor(if they still have those) on the circuit card for that injector solenoid not providing the power as needed. Guess you could try to run it with just one spark plug wire at a time to see if it is just one of the cylinders randomly not completing all 4 cycles.

 

[Dick Wells]

I guess the best way to explain how I know that I have a miss-fire, is to explain that the bike ran just fine, with the exception of the driveability thing, for almost 7,500 miles before it started to skip. Now, it's not necessarilly an "under load" skip, since on one occasio, I can leave a light at, say, 2000 rpm, with little clutch slip, and do it smoothly, and at random intervals, will start to pull away smoothly, and suddenly drop out a couple of firing impulses, which causes me to get back into the less friction mode, and feed extra throttle, real quick, in order to avoid a stall. The miss can come at a "neutral" throttle condition, say at 3500 rpm - flat road - any gear, not pulling, not backing off. It is very obvious that it won't happen under heavy acceleration, in which case it'll just rev right on up to any speed that the Old Fart has the guts to go. I haven't rolled it on at 55, in 5th, and let it go undr WOT, lately, like I had done a couple of times, last Spring, but I have no doubt that the darn thing will scoot from 75 to 95 just about as quick as it takes to say it! I used to let my buddies go out front about a half-mile or so, here on the Texas two-lanes, watch ahead for a black and white, and then roll the throttle on, like above and get real impressed by how quick the thing would run past 95! Maybe I'll try it again, tomorrow, out towards South Padre, just for kicks.

 

[Dick Wells]

Doggon it! I wasn't through with that post! I put a "wink" smilie at the end of the last sentence, and my cursor went up to the head of the post, and I couldn't move it. I'm through trying to figure out how to use smilies. Seems like every time I try, I lose something, sometimes the whole message.
Anyhow, yes, Ron supplied the heat-sink paste, and I used it, as I had on the last set of plugs, which came out looking like they hadn't been used, what with less than 150 miles on them. The HS paste wasn't even discolored.
A pcm issue wouldn't surprise me, where things are so random, and flaky. Used to be, if you had a miss-fire, it would be more consistent, like, if you had a vacuum leak, it would drive you nuts, but at least the thing was bad all the time.
Just FWIW, those old plug wires were not a surprise, either. The boots, on both ends, had a rust-colored deposite on them. One that I would expect to conduct spark all around the outside; anywhere but into the combustion chamber. The rear plug boot had to practically be torn apart to get it off, and it had been off of there in September. High time to change, for sure.
And, a BTW. I'm using StarTron in the gas, which I started over a year ago, because it, too, had a good affect on that driveablility issue. Danged ethanol, anyway!
Somebody want to clue me in on using all those neat smilies? Please.

 

[Farmboy]

This Is just a thought... I had a miss and my dealer found that my crank censer was grounding it's self out and dropping one cyl. about every other heart beat.

 

[BajaRon]

This Is just a thought... I had a miss and my dealer found that my crank censer was grounding it's self out and dropping one cyl. about every other heart beat.

I'd say it's BUDS Time!