why does my bike surge???

[rev 01]

Told ya to throw the fucker out <i></i>

[spready]

its funny that you mention bp fuel, cause i only noticed the surge after i filled up with bp premium. i cant say i remember using it before as its always more exspensive.i only used it cause thats all there was where i was
<i></i>

[BUSGO]

The fuel pump saga continues.

Well I chucked the regulator screen away and, you guessed it, it was still doing the low speed surge.
BUT, process of elimination, during my test riding I noticed that it only surged when or just after hitting a bump in the road or changing gears. This got me thinking that it may have been an electrical gremlin after all.

So I unplugged and replugged the following, making sure that they were tightly connected.
Fuel pump power,
Fuel sender lead,
ECU plugs, and
Sidestand switch. (I gave it a squirt of WD40 and pushed the button in and out a dozen times).

After test riding again for 50klm there is no stuttering but I will confirm the results after a longer spurt and I will also reseat both battery terminals just to be sure to be sure.

Apart from the clutch lever sensor, are there any other spots that could have worked loose to cause an electrical interference?
Rgds BUSGO
<i></i>

[rev 01]

Re racking electrical components as a cure all

ah yes, memories, memories

Anyway Bus, you've saved yourself endless future grief by ditching that thimble they call a regulator filter

Electrical ? You seem to have covered it. If it happens again, try substituting or bypassing the tip over switch & as you say, process of elimination for us equipment less back yarders

What fuel consumption figures are you getting
Excessively rich mixtures can cause tuning glitches in the lower rev range up to 4000.

If it's mapped right, should be 18/21 kilometers/ litre @ steady 100kph, anything around 14-15 means a remap to lean it off. <i>Edited by: rev 01 at: 8/2/06 11:55 pm
</i>

[teamslak]

Hi Guys, My 2000 model has had an intermittent surging problem for a few months, not enough to make me think it will stop and only at very small throttle openings.
I have just had my injectors cleaned and I think it may have been the problem.
The dash fuel thing just told me that I'm getting around 23km/l where this has been around 19-20 for the rest of it's life (59,000kms).
Haven't done many miles yet (about 100) but will let you know what its like over the next few weeks.
I'm geussing that with gunged up injectors that the poor fuel spray is/was causing larger drops of fuel to make the bike feel like it was going to stop, and then run fine again.
Cheers <i></i>

[BUSGO]

Thanks for the input fellas.
I've been averaging 18 to 20 Ks to the litre since I first got the bike.
I have been away for a while and will be back on the bike tomorrow to continue testing.
The fuel injectors are the only thing left for me to fix if there is still a problem.
Rgds BUSGO
<i></i>

[BUSGO]

I don't know if anyone is tracking this thread but I'll keep adding to it anyhow.

I seem to have fixed the problem with the fuel surge.

I reckon it was one of the plugs I reseated and I further reckon it was either the SIDESTAND sensor or the ECU plugs.
Since I have reseated the four plugs I mentioned earlier, the bike is running like brand new again.
Praise the lord - if there is one.......


Rgds BUSGO
<i></i>

[spready]

did your bike surge at any certain rev? mine seems to do at 3000 rpms, nowhere else. <i></i>

[BUSGO]

Spready,
I'm not sure we had the same problem.
My bike surged low in the rev range but when it got above 4000 it was ok.
As I said earlier it appeared to be when accellerating from slow or working up through the revs and I noticed in the end it would cough when I hit a bump or just after it.
I don't have any aftermarket electrics installed on my bike and I think the fault was a loose connection on the ECU.
Rgds BUSGO

"TAKE MY ADVICE"
I'm not using it anyway!<i></i>

[BUSGO]

Since my last post on this matter everything appeared to be fine, UNTIL LAST NIGHT!

The cheesecake started the surging again and even though it wasn't as bad as before it was becoming more consistant.

So once again I lifted the tank to check the wires but with closer inspection I FOUND THE BLOODY PROBLEM.

On the models with external fuel pumps there is a vacuum hose which runs from the regulator, behind the motor and up to the airbox sensors.
There is a brace that should protect this hose and I found that the bracket had been pushed up against the hose and was severly restricting the vacuum flow to the fuel regulator.
I relocated the bracket and released the vacuum hose from it's pinched condition and the result is amazing.
Instant throttle response and no bloody surging of the motor.

Here is a photo of the bracket in it's correct position.

After all my problems with this, I hope this is the end and that my findings can help someone else. Spready maybe this is your problem as well.
Rgds BUSGO

"TAKE MY ADVICE"
I'm not using it anyway!<i></i>

[spready]

i will have a look at that,thanks <i></i>

[spready]

I have installed a TRE and believe it or not the surging has stoped altogether which i guess is great news.
but can someone explain to me why my red fuel light is always on reguardless if the tank is full or empty??
plus the "f l" always flashes aswell.

im not too worried cause its worth it for the smoothness the bikes got now
any advice is welcome
<i></i>

[AstroBusa]

Geeze.... bloody excellent investigative effort Busgo ! Well done.

Any idea which years models have the external fuel pumps ? Might be something for everyone to check at the next spannering day. The older I get, the better I was. Regards.... Rob<i>Edited by: AstroBusa at: 3/4/06 4:59 pm
</i>

[BUSGO]

Can't help you with the TRE light problem Spready.
BUT for Turtle, the vacuum hose I found blocked was not the only one, there is another one that runs alongside the Throttle Position Sensor (TPS) on the left side of the Injector block. This one was also misdirected and was being pinched by the tank when the tank was bolted down.

While you are there, my local mechanic suggested that I check the connection to the airbox sensor that is just above the TPS. I did this while I had the tank up and even though it didn't appear to be loose, I gave it a squirt of WD40 and reseated it.

Since then all my surging problems have gone and even if I hit a big bump on the road there is no recurrence.
Rgds BUSGO

"TAKE MY ADVICE"
I'm not using it anyway!<i></i>

[BUSGO]

I think the pump went into the tank in late 2001 or 2002. Its pretty easy to tell though. If you lift the tank and there are fuel lines and a pump there, it is not inside the tank.


Rgds BUSGO

"TAKE MY ADVICE"
I'm not using it anyway!<i></i>