HARD hesitation, where do i start?!?!

[auto4dad]

Hi, names Steve first let me say this looks like a great board with a wealth of knowlageable and I'm happy to have found it.

...OK now to the problem. I just picked up a 99busa about a month ago. I got it from delandmotorsports in Tampa who took it on a trade for a 09 busa. The guy was a veterinarian and spared no expense when it came to modifying the bike. He put a lot of money in the suspension he added a full titanium exhaust a "full tune" and a few other things but they don't effect performance. The bike has been running fine for the last couple weeks. its very powerful and I am happy with the busa, but just yesterday out of now where I'm having a problem with a very HARSH hesitation. I found it while shifting fast from 1-2, but I have found that it will do it if I snap the throttle on-off-on. it will hesitate HARD before coming back to the "on" from the "off" The bike just falls on its face. If you leave a light at anything over half throttle in first then shift quickly to second and apply throttle she'll just fall on her face. If you are cruising in 3rd and snap the throttle then let out then snap it on again, it will just fall on its face. It has also shut off on me coming to a quick stop before too... And while typing this I remembered that I am now having to make sure the kick stand is "fully up" or the bike will not start....humm, wonder if its just that simple. Could the bikes kick stand be swinging forward while I am shifting or letting off the throttle? I will look into this, but my luck is never that good, where else could I look to find this problem?

 

[Mr Bogus]

fuel delivery.. pressure or filters (just the first place I would start) I think there are 2 screens/filters on the 99?

absolutely need to know the pressure available at the rail before getting too far down the diagnosis road..

 

[Kento-Moto]

Sounds like a fuel issue but I have heard of kick stand switch issues on other bikes but never on a busa. You could wire a bypass but then make sure your stand is allways up.

Also what color is the bike? Post up a couple pics plz and congrats on a good choice.

 

[auto4dad]

Thanks guys I will start with looking at the kick stand issue first and if I have no luck I will find out the pressure at the rail and go from there. It's odd that I just started with all these little problems (bike not starting unless I give the kick stand a nice firm kick after its up, stalling after a hard stop, and now a hesitation after a quick shift) it might just be the kick stand. I'll keep you guys posted, Thanks again!

 

[Mr Bogus]

might be that Ohlins rear shock... better take it off and send it to me... I will exchange it for a stock shock... No Really , I will do that for you!!

 

[99'busa]

Ya i'd start with the kickstand issue. Then see if prob. is still there. Could be pump or filters.

 

[Ezduzit]

 

[mike1180]

Welcome!

I agree, check the kick stand.

 

[Wag]

Also, lift the tank, remove the air box and make SURE all of your vacuum lines are still connected and that none of them have cracks.

You don't say how many miles it has on it.

What rear tire is that?

--Wag--

 

[Mikey D]

My hesitation was a plugged fuel filter. This is a known issue with Suzuki. If it is the insert filter it's only $28 and I have one if you need. If it is the cartriage filter, it is over $200 (Two hundered dollars - not a typo, a rip off!)

I wound up back flushing mine with gasoline. Coffee came out!

The cartriage filter is on the fuel pump in the tank. Be sure to get a new tank O-ring ($30) as well.

Best of luck!

 

[austinuhri]

Okay man, here's my take. I just recently had a hard hesitation problem on my 2000 busa and I just had to search for others that might have similar problems so I can help them out. I can see you've had almost the same exact problem to myself, so here's my story.
I'm a former service technician for general motors so I'm fimiliar with the engineering behind air/fuel and ignition problems. This Hayabusa is the first motorcycle I've owned, and of course I bought the shop manual the first week. I'd been doing all my own regular scheduled maintenance up until the 40,000 mile service which included the valve adjustment. This was July 2008. I chose the dealership closest to my house, PCP Yamaha Suzuki Polaris, and they really did me over. I suspect they did this to get my repeat service, seeing that this sort of problem would be small and insignificant at first and slowly develop into a hard problem. It took me several months to properly diagnose since I never thought to check the dealership's tune-up work.
Here's how the symptoms started:
The bike started to develop a slight hesitation problem toward the end of August 2008. It seemed to act up only when I accelerated in 1st and 2nd gears. Then over the course of the next 30 days, it became more violent, but still remained in the first 2 gears. Then after another 30 days, further hesitation was happening and I lost interest in riding. I ran several diagnostics on the bike to locate the problem. I first found that one vacuum hose leading to the preheater was cracking. (the preheater is the vacumm valve which is attached to the bottom of the air cleaner and regulates, with a plastic dampener, the air fuel ratio in comparison to how much throttle being applied.) I was excited to learn about this hose being cracked because it would definitely lead to the hesitation symptom I was experiencing. However this ended up not being the problem and left me very frustrated.
I'll get to my point now:
I finally, just this past weekend, searched very carefully throughout the entire engine compartment for more faluty components. I found one hose was squeezed between some of the throttle body mounting assembly. I couldn't beleive my eyes. The people who did my valve adjustment actually reassembled the throttle body on top of the main vacuum purge hose. This hose comes from the charcoal canister at the rear of the bike and connects to a "T" valve which leads directly to the base of each of the four throttle bodys. I will include an example picture here. Anyway, the squeezing of the hose didn't completely block the air passage right away, but after several weeks of heat damage, due to it being so close to the intake manifold, it did gradually create a blockage great enough to cause this harsh hesitation I'm writing about here.
If you have any questions please don't hesitate to e-mail me at austinuhri@yahoo.com. Thanks for reading my post.

 

[mike1180]

Welcome Austinuhri !
Nice job troubleshooting.

 

[MelodicMetalGod]

austinuhri,

to the .org. Excellent diagnosis!!! Thanks for sharing. Hopefully you're shop made an honest, albeit bone-headed, mistake and hopefully we'll never NEED this information. That said, it's always better to be fore-warned and fore-armed.

Thanks!

 

[austinuhri]

Thanks guys for the kind words. It's nice to be welcome. Oh, and I wanted to say, nice photo manipulation. I'll have to scrub-up a swell picture like you two have done.

Austin over and out