| Author | Message | ||
     Spatten1 |
I was at the track yesterday and my bike repeatedly bogged in the same turn. It is bad enough to be dangerous. It happened after decel from about 120 into an 80mph turn. It felt like the bike loaded up on decel, and would stumble at 2k for about 2 seconds before finally coming back to life. I could avoid it by staying on the throttle and rolling off into the turn, but that was not proper entry speed and could cause a dangerous situation with a rider behind me. At another track I had problems with the bike stumbling badly under 4k after both straights and running fine the rest of the time. I am running a 2003 XB9 with race ECM, filter, and Drummer. Now, this bike runs fine on the street, aside from when there is a big change in temperature, then it can take a while to get adjusted then runs fine. The first time I had problems at the track the temp had increased by about 20 degrees since my last ride. Yesterday it was about 20 degrees cooler than my previous ride. I don't know if this is contributing to the problem or not. I'm trying to figure out if something is wrong with my bike or if this is endemic behavior for the ECM. Or, does the ECM just have issues compensating for temp changes without street type steady state riding. What I am sure of is that I don't feel safe bogging in an 80mph turn in close traffic. Any suggestions would be greatly appreciated. | ||
| Max |
Sound me like it was loading up. What gear were you in doing that turn? | ||
| Reepicheep |
Were you doing a hard deceleration right before? I know Hals had a problem with the fuel pump that they fixed, and during the live "Chat with Erik" (which was much better then that, an entire team of really neat folks were there), this came up:
That was Dan Hurda, lead powertrain engineer. I believe the fix is built into the fuel pump, so a new fuel pump might be justified for racers. | ||
| Diablobrian |
Is it bogging when you are hard on the brakes in a hard right turn, with half a tank or less of fuel? Our race bike was doing that. Other buell racers at the track advised not going out with a fuel tank that was not full. The fix was to install a 05-06 spec fuel pump, the pick-up tube is supposed to be revised so the pump will not starve when hard on the brakes. This problem did not show up at a street pace either. BTW that was my question during the chat(no applause needed) (Message edited by diablobrian on September 05, 2005) | ||
| Gearhead |
This happed to me only under hard braking on the main straight at the track day 8/29 at MAM. I filled the tank before the next session then topped it off before each session after and never had that problem again on my '04 XB12R. | ||
| Spatten1 |
Man, you guys sound right on target. It was after decel in top gear under hard braking. Trying to get back on the gas in the turn at the end of the straight (3rd gear, left hander) was where it bogged. I'm hearing two different things: 1) keep the tank full OR 2) get a new fuel pump ('05-'06 spec.) Thanks guys, I feel much better knowing that this can be fixed with the fuel pump / fuel level. I was really concerned that it was ECM progamming, which would be much more difficult to deal with. I love this board. | ||
| Buelldyno_guy |
I think you have this all figured out by now, but we use the new pump on our race bike along with two pieces of fuel tank foam. One small one cut to fit into the space just to the right of the pump, with the other larger piece just forward of the pump. The new pump also helps with the issue of the low fuel level driving up the AFV on street bikes. I have a question for one of the "Anonymous" posters, can the parts department supply a plumbing kit to re-plumb the old pump. The new pumps are in limited supply and it is just the P/R valve, tubing and filter arraignment thats different? ... Terry | ||
| Cmm213 |
Good info guys I will remember this in the future |
