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Discussion Starter #1
Hey I just bought a 2001 750SS for $900 off of craigslist and was wondering what could be the cause of the low rpm hesitation only at a very low throttle settings. As soon as I start to give it more throttle or get up in the rpms it will run fine. It is a pretty strong hesitation. Could that be caused by needing to get the valves adjusted? Also, it has been sitting for the past two years in a garage and I am not sure if it could be caused by that. I didn't believe so because it is such a strong sputter. I could see if it just hesitates a little, I would believe some bad gas or something. Oh yea this is my first bike. I'm so excited!:D
 

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What RPMs are you talking about? They prefer to be kept above 3,000. Is the gas 2 years old? I hope not! If so, get rid of it, put in some new (preferrably ethanol-free, hard to find) gas, and run some Seafoam or injector cleaner through it and see if that helps.
 

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Water

Welcome aboard JKLATT16 ....the adventure has begun! Supersports are the best!

Check for water in the gas

1.) Did you drain the tank and clean it out?
2.) If not why not!!!!! "Two years" it sat!
3.) Do that.... add some "seafoam"
4.) Replace the fuel filter....
5.) if you still have problems clean all the crap out thats in there...
6.) Then come back here and tell us how it went....:think:
 

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Discussion Starter #4
Hey, it's a 2001 750ss with 16500 miles. I have ran seafoam through it. Gas was good color so prob no rust. I will look tonight with a flashlight. I just purchased a new chain and sprocket set (going up a few teeth) also have timing belts on the way. I will check valve lash soon and I already changed the oil with some synthetic. Last owner had regular oil in it. I got it for $900 but it needs some work. The owner thought it needed a new starter. It didn't, just a battery. But I wasn't going to tell him that. It has a bit of road rash on the left side and is missing the rear fairings. After getting the state inspection done and insurance on it, I have rode a lot more. So now a little more info into the hesitation problem. It will do it between 2500 and 5k rpm especially when I am at a steady state of speed. Full throttle, no problem. Partial throttle, problem. So that makes me kind of think that it might be a bad lambda sensor. It controls a/f ratio under part throttle. Under full throttle the ecu would run on a preprogrammed fuel and spark map so it doesn't use the lambda sensor. Also, I need to still change fuel filter. Any thoughts would be appreciated. Coils? I don't know. Still a good deal for me.
 

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I had the self same problem with my 900 for 2 years!! Mine is a 2002 but I got it new in a crate in 2010 and it had the same problem you are describing from new. I've cured it by doing the following...

1. Download the TPS setting instructions from Brad Black's site and follow them exactly. Download Ducatidiag (free or donation once you have it working) and buy the leads from amazon-cost about £20 (to set the TPS by degrees rather than backprobing the wires for voltage.) The TPS should be set to 2.47 degrees. Do not be tempted to skip any steps because the TPS zero reference point needs to be set before you can advance it to the correct setting. During this procedure you will also balance the throttle bodies and set the air screws. My TPS was so far out it was a joke. My TB's were out of balance too. You'll need some basic handtools and access to a carb balancer. You will probably need to buy a long screwdriver for the centre balance screw.

2. Increase the idle speed to about 1400-1500rpm by further turning out the air bleed screws by equal amounts. As a guide my screws are 2 turns out.

3. After all this enjoy stumble free off idle operation.

Let me know how you get on

Hope this helps

Regards

Kurt






3
 

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2001 900SSie
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So that makes me kind of think that it might be a bad lambda sensor. It controls a/f ratio under part throttle. Under full throttle the ecu would run on a preprogrammed fuel and spark map so it doesn't use the lambda sensor.
There is no lambda sensor.

Our bikes work off maps based upon throttle position, air and engine temp, rpm and air pressure.

The throttle position sensor is a possibility, but I would start by doing the simple things first as others have suggested. I.e. you know it has clean filters, fuel, injectors etc., then see if the problem still exists.
 

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Discussion Starter #7
There is no lambda sensor.

Our bikes work off maps based upon throttle position, air and engine temp, rpm and air pressure.

The throttle position sensor is a possibility, but I would start by doing the simple things first as others have suggested. I.e. you know it has clean filters, fuel, injectors etc., then see if the problem still exists.
Yup, cool. I just looked for it this morning and sure enough...None. Thanks though.
 

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Discussion Starter #8
I had the self same problem with my 900 for 2 years!! Mine is a 2002 but I got it new in a crate in 2010 and it had the same problem you are describing from new. I've cured it by doing the following...

1. Download the TPS setting instructions from Brad Black's site and follow them exactly. Download Ducatidiag (free or donation once you have it working) and buy the leads from amazon-cost about £20 (to set the TPS by degrees rather than backprobing the wires for voltage.) The TPS should be set to 2.47 degrees. Do not be tempted to skip any steps because the TPS zero reference point needs to be set before you can advance it to the correct setting. During this procedure you will also balance the throttle bodies and set the air screws. My TPS was so far out it was a joke. My TB's were out of balance too. You'll need some basic handtools and access to a carb balancer. You will probably need to buy a long screwdriver for the centre balance screw.

2. Increase the idle speed to about 1400-1500rpm by further turning out the air bleed screws by equal amounts. As a guide my screws are 2 turns out.

3. After all this enjoy stumble free off idle operation.

Let me know how you get on

Hope this helps

Regards

Kurt






3
Brilliant...Thanks!
 

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Brilliant...Thanks!
you're very welcome. You need...

1x VAG KKL 409.1 EOBD lead and
1x Fiat/Alfa/Lancia EOBD adaptor lead. This one must have the positive and negative battery connection leads

The diagnostic socket is behind the left seat panel at the back of the bike. Its a 3 pin connector with a cap over it.

Let us all know how you get on

regards,

Kurt
 

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Discussion Starter #10
Okay this might sound weird but I fixed the problem with the hesitation. Today I changed the sprockets and chain to a 41 rear and 14 front. The front had 1 broken tooth and the rear was binding badly. I could hear a pop sound once every rotation of the chain and for about 45 degrees of rotation it would bind and actually slow down while driving. Now it rolls sweetly. And a byproduct of me doing this and changing the oil is it doesn't stutter or misfire between 2500 to 4500 rpm. I don't know how it happened but it runs like a new bike now. I just downloaded the ducatidiag and order the cables. I had one backfire through the intake today. I am sure this will fix it. Thanks for all the help. :yeah:
 

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i've insulted many owners over the years by suggesting their abused and neglected chains could be responsible for the perceived low speed running issues. apparantly insults their superior knowledge of everything, but you get that.
 

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i've insulted many owners over the years by suggesting their abused and neglected chains could be responsible for the perceived low speed running issues. apparantly insults their superior knowledge of everything, but you get that.
Yep - agree.

My signature here used to be ...

"There are a lot of experts out there, but fortunately there are others who know what they are talking about"

There is a tendency, not just with bikes, to jump into the super techo reasons before looking at the simple things.
 
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