| Author | Message | ||
     Choose_a_username |
I am not sure what happen but something is wrong with my bike. In mid October of this year I took a long ride (200 miles) and on the return leg the engine started to feel like it was "skipping" not miss-firing, the power level seems ok and the bike started and idles well. This stared about 20 miles after getting gas, I looked the bike over on the side of the road and I could not find anything really wrong at the time, being about 50 miles from home I pressed on. The following week I rode the bike on and off, the skipping was still there, I thought I had bad gas so I ran the fuel down to the reserve and topped off with fuel from a know good source. Engine is still skipping. I am not sure but it kind of feels like one of the valves might not be sealing 100% as I have no smoke from the exhaust and no other loss of engine oil (rings should be ok), my next step is to preform a compression test then a leak down test. What say ye? Anything else I should look at or test? Thanks Paul B 1998 Buell Cyclone | ||
| Cyclonecharlie |
If the bike starts and idles good, I don't see a compression problem. I would pull the carb and look for a blocked main jet. Also pull the plugs and see if they look the same. You could have gotten some water in that tank of gas and just running it down and re-filling isn't going to get rid of it.Look in the bowl for signs of water and if you find it, put an additive in the tank to absorb it.Good luck | ||
| Greg_cifu |
You didn't say what conditions it was doing this under. I promise it's not partially leaking valves. You would NEVER feel that, hear it or anything else. The first time you would know you had a partially leaking valve is when it was burned from blow-by gas and the engine didn't run anymore. Stock air box or aftermarket? Any other mods like a Lightning cam? Is this a stumbling when you crack the throttle open at about 2500-3500 RPM? How long have you personally owned the bike and how many miles (total) have YOU put on it? | ||
| Two_seasons |
Check your plug wires. Each should be approx. the same ohm's value. Next, check your coil. Ensure the plug wires are well seated and the plug wire boot is tight. Check the coil connections too. Make sure they are tight. Check all grounds. I assume you have a Field Service Manual. If not, Al or Joanne at American Sport Bike can sell you one. Your roads in Baltimore are about as good as ours in Waukesha...shizen! Welcome to BadWeb...  | ||
| Choose_a_username |
Some good questions, thanks. The event: Weather was cool in the morning 50*F and warmed up to about 70*F mid day, riding was all local routes and back roads no interstate, some "spirited" riding along the way, rider only, about three or four stops each way. Ownership and Maintenance: This is my second bike. I picked the bike up in early August, over all the bike was in poor to ok condition but did run very well with no leaks or "odd" noises from the power-train. I did have to replace both tires, all the brake pads, head bearings, oil change, and a few other small things to get the bike on the road. Since the work was preformed no major issues and the oil is checked every at every fill up. Modifications: Vance and Hines muffler and a force widener air intake are the only know mods. Note: I did order a BS1AB air filter from Airtech (30% off  ) but will not be here for three weeks. From the above comments I should replace the spark plugs and wires to start. Thanks guys. | ||
| Edv |
Also check for water in your fuel | ||
| Cyclonecharlie |
Force Winder intake...make sure the vent for the carb is not obstructed. This happens a lot. Will start and idle good, falls apart on acceleration. Sound familiar? | ||
| Greg_cifu |
All good details but, I was fishing to find out how many miles YOU have ridden this bike--trying to discern if it's a condition that didn't exist before or if it was always there and you're just learning the quirks of the bike. My 1998 Lightning will regularly surge and spit back through the intake when going from a 3K cruise, then cracking the throttle open. It's worse at certain altitudes and temperatures. The biggest factor is engine load. I have to be on a slight grade and set-throttle to have it really misbehave when the throttle is opened. I attribute it to the Lightning cams and the Buell race air cleaner (which shortens the intake length). My S2 and RS1200 don't do it with essentially the same carb and air cleaner--but they don't have the Lightning cams. My S3 DOES have the Lightning cams yet doesn't do it; It has the tuned, stock air box in place on that one. I'll bet if you put the stock breadbox and muffler on it, things would be fine. | ||
| Harleyelf |
Cam position sensor might be failing. | ||
| Choose_a_username |
Greg, this condition started after putting almost 2500 miles on the bike (12,0xx total) between August and October. The skipping seems to be in the lower RPM range but I can feel it in the upper range also (not as much) Harleyelf,do the carb bikes have cam sensors? Thanks Paul B | ||
| Choose_a_username |
Forgot: As for altitude the area I ride in is near or at sea level, and temperature seems to have no effect. | ||
| Dannybuell |
the cam sensor is in the nose cone, a part of the electronic ignition. | ||
| Choose_a_username |
That is good to know, thanks. So the bike has a crank and cam sensor, correct? Or just one ignition sensor (cam)? Paul B | ||
| Brinnutz |
Does this happen as you are accelerating through the first few gears? | ||
| Choose_a_username |
Brinnutz, this happens at all engine speeds and all gears, clutch in or out, but is more noticeable at idle and low RPM. I can also feel the skip at cruising speed and higher RPM. | ||
| Reepicheep |
Good question! And if it only happens in 1st or 2nd gear, I know exactly what your problem is. | ||
| Choose_a_username |
This happens in all gears. Now I am interested what could cause a skipping in 1st and 2nd gear only? In case I run in this event. Paul B | ||
| Reepicheep |
Worn dogs. The gears sort of engage, then it feels like they jump a tooth, then engage the rest of the way. It's like somebody hit the back of the bike with a sledgehammer. I had a worn D220 rear tire do it as well. A strip of tread peeled off and it would "jump" about 1/4 rotation under load then catch again. | ||
| Harleyelf |
Yes, I upgraded to a Drag Specialties dual-fire Cam Position Sensor when I retro-graded to my antique SU carburetor; it all goes together with my '98 M2 module to make a very dependable ride. See my profile photo. The ignition system can be made into a Sportster with just a few parts. Toward the end with my original CPS, I had so many extra sparks the engine would try to run backwards. |
