Busa Suddenly Runs Bad

Redboost

Redboost

Registered
Hi all busa members !
Need help with my bike... the bike is a gen 1 1999 Hayabusa that started to backfire, misfire and have a bad fuel economy. You can litterly smell the gasoline from the exhaust.

When i drive it with very low throttle up to 3-4 K Rpm the bike starts to misfire, when i pass 4krpm and give it more throttle it runs better But not 100% Good.

I have changed the plugs, the recifire (mosfet), cleaned the Air filter and checked all vacuum hoses.
Made a order yesterday on a new Yausa battery, stator, coils, new plugs and a new air filter.
My mecanic thinks Its the MAP sensor, But i want to hear you guys if anyone had the similar or same problem?
(I have also changed/upgraded the fuel pump, cleaned the injectors and changed to fuel pump hoses last year)

Any thoughts?

/Marko
 
Have you changed the fuel pump filter? There are actually 3 filters in the out of tank, pump assembly, the main small fine canister, a gauze filter, behind the pump and a small dished metal filter, under where the regulator plugs into the pump assembly, there is also a long gauze filter, that is submerged in the fuel tank, that is connected to the fuel tap, a couple of small Allen bolts hold it into the tank, it's worth removing this, as the early busa suffered terribly from fuel tank corrosion.
I'd eliminate the fuel system, before changing coils and electrical components.
 
Yes the filters is changed ! :) Also added a filter from the gas tank to the pump just so the pump wont get clugged.
 
A failed water temp sensor could be telling the ecu, that the bike is cold, thus over fueling the bike at low revs, this could bog down the bike at low revs, have you removed the plugs, to see compare the difference between the 4, when the bike is playing up? With the bike running, can you disconnect one coil at a time and notice any engine note change? Can you also do this with the injector plugs? Have you carried out a throttle body sync?
There's also a compression test and leak down test, that could be carried out.
 
So I did check the TPS and MAP sensor and both have good voltage reading 5V.
Because the backfire and flames from the exhaust when i let of the throttle I think its the ignition coils..

I have some pics here how they look and how the spark plugs look, I did put a PCV Map that I downloaded from PC website for Hindle slipon, the map seems to be very lean when I compare it to my custom map.
What you can tell from the pics on the sparks is that cylinder 1 and 3 is running leaner than cylinder 2 and 4.
That because you can se that the tip on the sparks are white on cylinder 1 and 3 and black on cylinder 2 and 4.

The injectors have been cleaned two years ago, done 1500miles since they where cleaned, fuel pump and filters where changed then also.


http://imgur.com/a/Q4a97


http://imgur.com/a/tBlRw


http://imgur.com/a/EQv6n

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21105446_10210442122076489_5235675094394635210_n.jpg


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1999 plagued with fuel issues. Add secondary helper pump as well as change fuel lines every 2 years.

In your case that one plug looks suspicious. Swap coils (if you dont have spare) and see if the other plug changes colour.
Gas tank notorious for rusting out as well internally. I would get all fuel related work done regardless.

BB
 
Can you do some 'methodical' swapping around of plugs and injectors, to eliminate possible faulty plugs/injectors?
Can you see if there is a difference in the coulour/condition of the injectors, on the cylinders/plugs, that you suspect of not firing?
 
I am waiting on a new set of coils, new rotor, new yausa 14s battery, new sparks and a new air filter.
If that is not solving the problem I will go and buy a new TPS and a new MAP sensor.

Will keep you guys updated!
 
Redboost said:
I am waiting on a new set of coils, new rotor, new yausa 14s battery, new sparks and a new air filter.
If that is not solving the problem I will go and buy a new TPS and a new MAP sensor.

Will keep you guys updated!
Click to expand...

Before you spend a ton of money on a new TPS there is a simple way to ck if it is out of adjustment. You can also check its voltage and ohm resistance. Easy to do! A bad or out of adjustment tps would make your bike run bad.

 
The TPS is set to -C00, I am gonna give you guys and update as soon as the Stator and Coils arrive, is it hard to replace the stator ?
 
The stator comes with the ckps (crank shaft position sensor) integral, so that will also eliminate your ckps (they do fail, I have personal experience of this, don't ask lol), not a particularly difficult job, put a tray underneath, to catch a small amount of oil, you might also need another gasket but can make one if you eat cereal, once you have the ring of 8mm headed bolts out, find a place to get a flat blade screwdriver in and give it a wiggle, to break the seal, then you will need a little force, to put it squarely away against the pull of the magnets, it's not a terrible job but a bit of care is needed to get a leak free seal, after fitting the new one.
 
Hi.
Long time and not so much going on lately, changed the Stator and Coils, put the new Yausa battery on and guess what? The bike runs worse, test drove it for like 50-60km/33-37 miles and the busa in running at best between 3500 and 6000rpm with very little throttle, at full throttle the bike is misfiring like hell, but no backfire?
From idle to about 2500rpm it runs "okay" but right before 3000rpm it starts to misfire and behaves like an old carb motorcycle that is running too rich or having a bad spark plug?

I changed the stator to a stator from eBay, Electrosport Updated ESG748 model that has a 40% more output over stock unit, the voltage regulator/rectifier is a MOSFET, Iridium spark plugs, and CoilSpec ignition coils.

What the hell can it be now? Tomorrow I will try to change to my old Ignition Coils just because it ran better, had it on a dyno today and the shop told me it must be something with the electricity ( they don't know where to start looking, they say it could be anything ).

So before I leave the bike t0 the dealer there my plans are :
1. Change to the old ignition coils and see if the bike runs better
2. If the bike still runs like crap can it be the eBay stator?

The thing is, this all happened one day when I was out riding, from nowhere the bike started to misfire (no fault codes) and would misfire when the bike was hot, I thought it could be the coils but seems now that it can be something else?

I will post a Youtube video soon so you guys can see for your self.

/Marko
 
Redboost said:
...had it on a dyno today and the shop told me it must be something with the electricity ( they don't know where to start looking, they say it could be anything ).

2. If the bike still runs like crap can it be the eBay stator?

The thing is, this all happened one day when I was out riding, from nowhere the bike started to misfire (no fault codes) and would misfire when the bike was hot, I thought it could be the coils but seems now that it can be something else?

/Marko
Click to expand...

Regarding if the new stator is also bad, only testing can answer this. It is always possible that the best new component arrived bad because the vendor put a bad part back in stock. You need to check voltages along the way especially after buying a new component: DC Voltage at battery, DC voltage of the rectifier output at idle & 5000 rpm, AC voltage of the stator legs at idle and 5000 rpm. (See the detailed factory manual instructions.) Do this when the engine is hot as open circuits may occur only when hot.

Check for a short by putting an ammeter between the battery & black cable (with the bike off.) I don't know your bike but the max current should be something like 1mA, 2mA or 3mA.

Have you inspected the grounds? If one system's ground output burned up, it can affect a lot of other things. The ground for each wire going into a ground block or to the frame must be good. Look for burn marks or a loose wire.

Check that high-power accessories like the headlights are working when hot. Check that those connections are not burned up.

These are the types of electrical issues which happen all of a sudden due to age. Unfortunately the process of elimination of each and every issue is your friend here.
 
Hi Everyone

So today I changed back to the OEM coils and the bike now runs great!
They gonna put the bike tomorrow on a dyno to give it a custom map and setup the quickshifter.

Must be the stator or the CKPS that was bad, I will drive it for at least 2 weeks and then see how the plugs look.
The CoilSpec coils ware crap, don't know what to do with them, when I compare them to the OEM they feel very light and cheap. ( they ware 100 dollars for a set of 4 )
What is the best to go with? new OEM coils or other aftermarket?

/Marko
 
Redboost said:
Hi Everyone

So today I changed back to the OEM coils and the bike now runs great!
They gonna put the bike tomorrow on a dyno to give it a custom map and setup the quickshifter.

Must be the stator or the CKPS that was bad, I will drive it for at least 2 weeks and then see how the plugs look.
The CoilSpec coils ware crap, don't know what to do with them, when I compare them to the OEM they feel very light and cheap. ( they ware 100 dollars for a set of 4 )
What is the best to go with? new OEM coils or other aftermarket?

/Marko
Click to expand...
So it was the coils because my bike is doing the same thing But mines doesn’t even starts it was running good then it started stuttering on low RPMs and it’ll shut off started miss firing it’ll run good and high RPMs as long as I don’t let go of the throttle I did run a test on the coil’s primary test gives me 00 and the secondary gives me 13.9 just order a new set of coils it told me it was the camshaft sensor replaced it but nothing
 
Josue338 said:
So it was the coils because my bike is doing the same thing But mines doesn’t even starts it was running good then it started stuttering on low RPMs and it’ll shut off started miss firing it’ll run good and high RPMs as long as I don’t let go of the throttle I did run a test on the coil’s primary test gives me 00 and the secondary gives me 13.9 just order a new set of coils it told me it was the camshaft sensor replaced it but nothing
Click to expand...
Welcome to the ORG!
What year is your bike? Post up some pics so I can be jealous (again).
 
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