Bike ran fine for half a track day then suddenly no power under load, hard to accelerate more than 60 mph and very slow to get there. It does not over rev, just bogs down. It starts, idles and revs fine. No error codes. Stock bike, 20k miles. I have been pulling parts off of my same model race bike. It is not missing. Replaced spark plugs, old ones looked fine. Swapped gas tank/pump. Swapped fuel injectors. Swapped Coils. Exhaust valve was sticky, wired open. throttle position shows accurate via dealer mode. valves checked/adjusted in the last 1 or 2k miles. where should i look next? I have not swapped any sensors yet. Havent checked compression. Thanks!
any chance it's something dumb like a kinked hose or cable? revs okay in neutral, but not under load?
clutch switch only takes out likr 10-15hp on the top end and cuts max rpm by 3k. no problem at all getting to 60mph though
I picked up a test tool on the way home today. I warmed the motor, tore it apart then ate dinner, cuz I have a-d-d I guess. So pretty much the test was luke warm to cold motor. Cylinders 2-3-4 showed 185-175-185. I tested #1 two times, both times at about 175. The odd thing that noticed (scared me) is that around 140-150 psi #1 started to make noises. I couldnt tell if then noise was from inside the motor like a valve or somethin or if air was escaping the test tool. I put the tool back in a 3rd time and recorded with phone to show you guys, but this time it would only reach 155 and no noise. I put the battery tender on it and will check again tomorrow, maybe it just drained too low. Negative. 90% street bike and ran fine prior. a) not fuel related. any hoses I should look for, like engine breathers? b) I ran it side by side with my bike and it seems to be close enough. I will try this next.
Follow up- Battery charged. Tested again, #1 two new attempts now shows shy of 190 psi. Tested #2 again for comparison, still shows 185 psi. Will try ecu swap in the next few days, donor bike needs its parts back.
If you slightly rolled off the throttle whilst underload and not preforming, did you notice it try to clean it self up so to speak?
Swapped ECU, no change. New information noticed... 1st gear seems to stop around 8k rpm, 2nd around 6k. I had this happen on my 05 750, would quit about 8k rpm, it was a bad fuel pump. I have ruled that out already. Bad sensor(s)?
Location? I had this happen on a K3. It was a vapor lock on the vortex fuel cap not venting You may have a similar issue Also check the fuel sock, make sure it is not clogged
Map sensor! Does it get worse the higher the gear you are in, and the faster the speed! So it does not know the ram air is increasing the air box pressure. Same thing used to happen on carb bikes if the float vent line was not connected to the bowls on ram air bikes.
and they don't sell the servo. You have to get the entire throttle body. Quick and cheap fix is to remove the secondary plates.
I swapped air boxes, no change. I assume the sensor on top of airbox is not the MAP. Which one is the MAP? there are 2 hoses off the airbox. throttle body already swapped. ---- So the GF has been doing most of the test riding (her bike) while I do the drinking and tinkering. I rode it last night, and when it tops out in 1st gear around 7-8k it acts like it has hit the rev limiter. It felt very much software limited and not mechanical, if that makes sense.
On the 05/06 1000's the fuel hose would get kinked sometimes when you lowered the tank and it works do exactly what you described at around 7k. Might be worth checking, or not
