| Author | Message | ||
     Buelltastic |
The last few times that I have spent extended amounts of time on the freeway I have had the bike hiccup at 4,000 RPM. Usually just cruising along and slowly will hit the 4,000 mark. It has only done it a few times, but at that rpm point the bike will feel as if it misses or losses power for just a quick moment, just enough to feel a small jerk and will then continue to accelerate. This only seems to happens under light acceleration. Any knowledge would be appreciated. Thanks | ||
| Oilrigpilot |
Hey Buelltasic. My buddy bought a "race" ecm and we installed it... no problem at first. Along with his Buell "race" exhaust... he was in great shape and it sounded good. But then it started "hiccuping" at 4-4.5 rpm. WOW - That word attracted me to your post. It could only be spark, fuel or air... Right? Good plugs, (only 3k on bike)... Good air, (again, almost brand new cleaner) So - just for giggles I put his STOCK ecm back on and the problem now was GONE. By the way, the race ecm got so bad that i could throttle his bike up to 4k in neutral and it wouldnt stay put - it would surge...as if I was not holding it right at 4k... so we changed it back to stock... Now in process of a remap with his stock ecm and we'll see. Can you replace the ecm first and see if that was the prob.... see ya- robert long | ||
| Tq_freak |
Try having the TPS reset, sounds very similar to what others have complained about in the past. | ||
| Exitlandrew |
I had the same problem when I chopped my airbox. youre just not tuned right more than likely. | ||
| Buelltastic |
The bike is totally stock. If reseting the TPS may help, how would I do it. It also likes to backfire every once in a while at very low rpm, such as taking off from a top sign. Thanks for all your responses thus far. | ||
| Metalstorm |
You need the scan tool (can't remember the exact name at the moment) from Al at American Sportbike to do it yourself. Otherwise you need to bring it to the dealer for a tps reset. From what you describe, I would get the tps reset first before digging around for other possible causes. Start with the simplest & most likely possibility (tps needing to be reset) and work your way toward the more complex. | ||
| Davo |
Buelltastic, The race ECM and the stock ECM jumps spark advance an extra 43 degrees from 35 degrees at 4024 rpm. If you are popping right at 4K I would suspect a combination of issues: 1. excessive spark advance- retard initial timing about 3 degrees and test ride. 2. Lean condition due to race air cleaner and a transition from closed loop to open loop at 4K as well. There is a lean spot in the curve. If timing does not fix the problem then I would go to a dyno and get a run with a wide band O2 sensor. Any time you re-fuel you need to re-time and reset TPS. (Message edited by davo on July 02, 2006) | ||
| Davo |
Another thing to try. See if it pops at speeds less than 60 mph at 4K. You You might have to stay in 1st gear. If it doesn't pop then once again I would look at the timing. Are you having any surging? | ||
| Mesafirebolt |
I have to agree, mine has the same symptoms but the "mis" is at 3K. It also will backfire when taking off from a stop sign. I just had the TPS reset but nothing changed, runs just as it did before. What do we do now? I'ved lived with tis for over a year... | ||
| T9r |
My 03 9R, Race ECM & race Muffler, ran really crappy before I replaced the intake seals. I've read that if your bike is a daily rider that they will need to be replaced before 10k miles. I had more surging from the engine as well when the intake was leaking. I started by checking my spark plug wires and the front wire was also warn (from riding against a throttle cable). It still runs a little rough until I get it warmed up, but not as bad as before. When I decel. it pops a lot now. Before diagnoising all this I bought the Technoresearch Diagnoistic software so I could set my own TPS and check for spark advance among other things. | ||
| Davo |
Check the initial static timing using the fuel pump turning on as the means for determining TDC instead of the Scanyliser. The book says the mark should be straight up. I had to set mine to the right. I would move the CPS counterclockwise only 1mm each time and then road test. After you check the initial static timing please post your results. Index the CPS before you move it so you can always go back to the stock setting. Be very careful not to over torque anything or you will strip the threads! The timing window plug only goes to 120 in.-lbs. That is only 10 ft.-lbs! CPS fasteners and phillips screws are just snugged up with a screw driver. Don't kill them. The engine and the casings are soft!!! |
