Engine Miss in 2nd

[Jay Willie]

I own an '07 coming up on 15k miles. I bought the bike in April last year with 9K and, since it was my first land missile, didn't really start crankin' on it until about mid-summer. I started noticing what I thought was a tranny problem under hard acceleration and only in second gear. The bike acts like it just 'shuts off' for a very brief second and usually between 70 and 75 hundred rpms. Some of the locals I talked to said it was a bent shift fork. After reading around a bit, I'm not sure that's the case. It doesn't pop out of gear, it just acts like a miss. Sometimes it'll miss twice in second, depending on how low in the rpms I start to crack the throttle. The condition doesn't show up under relaxed driving conditions, only when I'm taking it 'through the gears'. Only engine mods are a PCIII, speedo healer, D&D cans. The map has been changed to accomodate the cans (stock headers) and was a free download from the PC web site. Anybody ever dealt with this?

 

[OUTLAW1300]

Let me guess, your using full synthetic oil? I ran into the same problem years ago on my drag bike. Kept missing 2nd gear at around 5k rpm but was fine under normal ridding conditions.

 

[Jay Willie]

hmm...no, don't use synthetic and I'm not missing the second gear shift. The bike acts like someone just shuts it off for a very brief second and then turns it back on. Bike isn't showing any codes, I don't notice any lights, instrument or otherwise, going out. It always cycles through start up with everything arriving at 'ready', so to speak, before I turn it over. Always fires right up. No hesitation at any other point but in a flat out competition run (uh, on the street but, shhhh, don't tell anybody!) I'll lose about a 1/4 to almost a 1/2 bike length due to the 'miss'. Won't show up in any other gear, and like I said, depending how low I am in the rpms as to showing up once or twice. Don't ever remember any 'three time' events. It almost always occurs in the 7,000-7,500 rpm range. Thank you for your imput, though, I do appreciate you spending time thinking about it. Any help is appreciated!

 

[OUTLAW1300]

I know what you mean. Acted like it was dieing, running out of gas. when it happened to me I couldnt hear the engine (like it turned off then turned back on). It didnt do it once but several times. Didnt show any codes for me either. After pulling the spark plugs and found nothing, I pulled the PCIII and ran the bike stock with out the PC and it ran fine. So I hooked it back up and remapped the PC. Ran fine ever since.

Have you figured anything out yet?

BUMP

 

[OUTLAW1300]

Oh didnt mean to say "missing" more like cutting out

 

[busa-saga]

interesting. saving this thread for future referal. sometimes/rarely i get a neutral gear from 5th to 6th.mines an 07 too. i usually have to clutch in and out for it to go in.keep us posted

 

[rusheriv]

Sounding like buggy map loaded on the PCIII. I'd say pull it, give the bike a run to see if it clears up. If it does then try to re-download or get another map and re-flash the PC.

Fingers crossed for ya.

 

[Jay Willie]

Excellent advise, all!!!

I will pull up the existing map and look at the injector pulse timing in the rpm's I seem to be having trouble in. I have also given some thought as to the contacts in the gear indicator module located behind the clutch basket. I wasn't sure about poor contacts, etc. but the idea there may be a glitch in the fuel curve for the stated rpm's in the mapping of the PCIII rings a bell. Like maybe a 'lean' condition through that rpm range? Definitely worth investigating.

Thanks, again, guys! 'busa dot orgers are the best! Will bring an up date soon.

 

[GSXTacy]

Its 2nd gear, trust me. You will need a new fork, gear and shift dog. You can also have it undercut.

 

[kevmoxj]

Hey guys im new to the hayabusa and have a similar problem. Yesterday i took a long drive to chicago and noticed a few times when shifting from 5th to 6th gear it seemed to pop into neutral. Is there something i should be looking for?

 

[The Big Red One]

Its 2nd gear, trust me. You will need a new fork, gear and shift dog. You can also have it undercut.

XTacy is right on........those are the all too classic symptoms of a 2nd gear gone bad. Once you've been through it you come to know them well. What you think is a motor skip is actually a tranny slip

 

[Jay Willie]

I appreciate the help. It's been raining here and I havn't had a chance to by pass the PCIII, as was suggested, but I will keep everyone posted. Is there any way to check second gear without pulling the transmission apart? Could I pull the pan and see the fork, 'dogs', and gear from below? Thanks again for everyone's willingness to help.