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Discussion Starter · #1 ·
Hey
Have a few questions about a new to me 2002 998 I just picked up a few weeks ago
The bike was pretty clean 5,000 original miles.
Previous owner was the original owner, and supposedly took good care of the bike. The bike is pretty clean for something that is 16 years old. It is all stock exhaust for a pair of Termi slip on exhaust.

All of a sudden the bike is stalling under acceleration. Only under full throttle load, if I down shift and get it in neutral (while coasting after it stalls) and hit the starter button the bike starts right back up.
The only thing that I noticed different on the bike before it started to do this was that it took a while for it to actually fire when I went to start it today to take it out. It took about 10 tries of cranking before the bike actually fired up. ( I normally cold start it with the choke on and I dont touch the throttle)

Where would I even begin to start looking to trouble shoot this ?

I was thinking maybe fuel filter needs to be changed ? ( I ordered a new one today)
I just located a workshop manual for the bike, but it is not here yet.


Any advise on where to start is much appreciated
 

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Fuel lines in the tank need to be replaced.

If you don't think I am correct, fill the tank to max. If the problem goes away, then you know that you have a fuel line issue.
 

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A dicky TPS can caus this. A clogged fuel filter can cause this and as Namor :)has said fuel lines can cause it.
 

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Not just the fuel filter - lift the fuel pump off it's seat and there can be a lot of crud that collects there in 16 years.

** Important ** Order at least half-a-dozen fuel pump base-plate o-rings and watch several how-to's for replacing the plate into the tank. If you don't ruin at least 3 o-rings getting the hang of it, I will be surprised :grin2:
 

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Discussion Starter · #7 ·
Not just the fuel filter - lift the fuel pump off it's seat and there can be a lot of crud that collects there in 16 years.

** Important ** Order at least half-a-dozen fuel pump base-plate o-rings and watch several how-to's for replacing the plate into the tank. If you don't ruin at least 3 o-rings getting the hang of it, I will be surprised :grin2:
thanks
any chance you have the part number for the o rings
and can recommend a good place online to order them from ?
 

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As it's an older bike, I'd suggest pulling the tank and checking ALL electrical connections. Along the top fame rail there is a large diameter round metal connector in the loom. Take this apart and slide the two halves in and out a few times. These are round pin connectors and their fit isn't very tight. Doing this on mine solved some wonky things about 10 years ago. ** Be very careful with the quick disconnect fuel likes going into the tank. They're cheap ass plastic (unless they've been replaced with metal) and will beak with the slightest provocation. As others have stated, when the tank is off pull the pump and replace the internal hoses and filter. Get fuel line rated submersible in alkygas. It's easy to cut the o rings on the QD connectors. The tab you push to release them has sharp edges that cut them. Be sure the tab is pressed all the way in when working with these things. Grease the o rings.


Sooner or late you'll hit on the problem and it will be solved.
Another crucial thing is the grounding wire on the ECU. Be sure the terminals are cleaned well and tight.
 

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Discussion Starter · #10 ·
so it cuts out. then you pull the clutch in and the engine is stopped? and then you restart it and ride away?

what happens if you don't pull the clutch in?
it cuts out
wont accelerate anymore

pull the clutch in downshift to neutral
push the starter button and it fires up again

i havent done it and not pulled the clutch in and downshifter to neutral
 

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Discussion Starter · #11 ·
took the fairings off today and just wanted to check to make sure the battery connections were tight and battery was charging etc
its reading around 13.5v when running on the battery so that seems good

i cleaned down the starter soleniod terminals and cables and its not cutting out when cranking anymore so thats a plus

i pulled the tank up a little just to check the lines under it and it looks okay under there

also checked the ground wire on the side of the ecu and that was nice and tight

so i rode it a little more today

its cutting out in high gear when im over 5,000rpms and more than 3/4
throttle consistently
so thats leading me to believe its fuel related

i ordered up some of the fuel pump plate o-rings, fuel line and a fuel filter and ill pull that whole unit and clean everything out next week when they get here

someone above mentioned metal quick disconnects for the fuel lines
where would i go about buying those from ?
mine are still plastic under there

just on a side note the bike has termi slip titanium exhauast
should i be looking to add a power commander to the bike because of this ?
or should i just keep the stock ecu and leave it alone ?
 

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Just chiming in, as I have a similarly new to me old bike. I also had fuel pump issues with an RSV, which are the same in the tank. Fuel will eat away the lines in the tank. It's honestly very easy to work on that part, draining the tank is the biggest hassle. But I did it 3 times, don't ask, in my parking lot garage with hand tools. If your gonna take out the pump, do the entire thing!!!

You can buy a non factory replacement fuel pump motor so you don't have to change the entire assembly, or at least I could on the RSV. Also make you sure you get legit submersible fuel line:

https://www.amazon.com/dp/B0049BIGB6?tag=vs-powersports-convert-amazon-20

And do NOT use worm drive clamps on any of the hoses, use at least something like this and don't be scared to tighten the living fuck out of them, don't ask how I know.

https://www.mcmaster.com/#hose-clamps/=1datkkf

Here is a metal fuel QR setup from Motowheels:
https://motowheels.com/i-20905460-q...t-two-males-two-females-ducati-mv-agusta.html

It sounds like a massive job, and yeah it's stinky and I drank some fuel but it's pretty easy and on a bike as old as both ours, it's something that should "just be done".

ALL THAT BEING SAID, if this happens on a full tank of gas...I don't know if it would be the issue. The hoses start to leak and then the clamps don't hold and it starts to suck air instead of fuel when there isn't much gas in the tank. When your leaned over, accelerating, etc. Eventually the hoses will pop off, leaving you 100% stranded ;-)
 

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Discussion Starter · #13 · (Edited)
thanks for the reply

it is happening on a full tank of gas

after looking at the way the pump and filter are i think im going to add the metal quick disconnects and set it up so that the fuel filter is external and mount it under the seat
this way at least its easier to swap when its time to do the service on it

any other ideas on what the issue might be ?

i know im going to end up replacing a few things here one at a time until i find the issue

its almost like thebike feels like it hits the rev limiter and than stalls up around 5000 rpms in high gear
 

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Did you buy that bike in Connecticut?

I was gonna buy it but you beat me to it.

He said it had a 998R chip in it so you wouldn't need a power commander.
 

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Did you buy that bike in Connecticut?

I was gonna buy it but you beat me to it.

He said it had a 998R chip in it so you wouldn't need a power commander.
Interesting, is it dying under full throttle because it's to lean? It's fuel injected right so I mean......like...it should run pretty much all the time or no? I'm still in the "fuel pump system" camp. I thought about the same thing regarding an external, after taking that RSV tank off 11ty times....but I duno I don't think you want to do that.

The fuel system is under a shitload of pressure, so that's why the clamps have to be so tight on those in tank hoses and stuff. I'm not sure it can be replicated outside the tank. What you want, is a sorted pump, hoses and clamps, with metal disconnects...do it right, it will last AGES.

The fuel system should be good for an ultra long life I think....so just thinking, if it runs more or less at low RMP, the issue at high RPM would be electronic rather than mechanical? It looses fuel, it then looses spark and poof, it's dead.
 

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the fuel filter being inside the tank gives you a good reason to get into the tank regularly. these tanks get rusty, and looking in there occasionally is a good idea.

the 998 fuel hoses are rubber covered plastic. ime you can't just replace the connectors. you need half a metre of fuel hose for each side of the y piece.

it's only 3 bar pressure, so you don't need to over tighten shit like crazy. some of the rsv are 5 bar.

i'd check the rotation sensor gap.

what happens if you just pull the clutch in and hit the starter without selecting neutral? i don't understand why it won't come back by itself when it's rolling in gear with the clutch out if all you do is hit the starter.
 

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Discussion Starter · #17 ·
the fuel filter being inside the tank gives you a good reason to get into the tank regularly. these tanks get rusty, and looking in there occasionally is a good idea.

the 998 fuel hoses are rubber covered plastic. ime you can't just replace the connectors. you need half a metre of fuel hose for each side of the y piece.

it's only 3 bar pressure, so you don't need to over tighten shit like crazy. some of the rsv are 5 bar.

i'd check the rotation sensor gap.

what happens if you just pull the clutch in and hit the starter without selecting neutral? i don't understand why it won't come back by itself when it's rolling in gear with the clutch out if all you do is hit the starter.
yes im going to change all the internal fuel lines when i take the tank off and add the metal disconnects and do the fuel filter

when you say check the rotation sensor gap

where is that ?

and what should i be checking on it ?
(im still waiting on the workshop manual to arrive)
 

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Discussion Starter · #18 ·
looks like everything that i ordered including the shop manual should be here today

so ill start messing with it this weekend

if anyone else has recommendations on anything else to check while the gas tank is off please let me know

thanks
 

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looks like everything that i ordered including the shop manual should be here today

so ill start messing with it this weekend

if anyone else has recommendations on anything else to check while the gas tank is off please let me know

thanks
I just did a how-to on changing out the fuel line quick disconnect fittings, in the Tech section (with photos.) Don't be tempted to use worm-gear clamps on the external lines. The crimp-on hose clamps are the only way to fly, in my opinion. They can be a real pain in the butt to find, though... I must have called every auto part store on town. Finally, a friend told me to go to Home Depot, and get a set of PEX clamps (any home store should have them). Bingo! Get a few of them (stainless), and pick up one of their crimping tools. Also, don't ignore the external vacuum lines going into the tank. One of mine was completely collapsed, so I am going to change it out with an actual fuel rated line, tomorrow.
 

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Had similar, found alternator nut had come loose and deposited small ferrous particles on crank position sensor.
 
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