[asphalt]

Hey guys, I picked up a 2000 ST2, and love it, mostly.... I got it, and immediately went on a 1000 mile ride to get a good handle on how it ran. I was happy with most of the ride, except for two issues.

1. Fueling. Previous owner said it had a valve service from DucShop (with papers to show it) and I love their work, but after the first tank of gas since then, it had a intermittent shudder. He thought it could have been bad gas. I have run several tanks through it, and its still there. I know since DS did the valves that it can't be that, Its only at load, usually at low RPM, clears out after a clutch pull and rev sometimes, other times its there for 10 minutes or so. High RPM and its clean and clear, all the way to.. well.... I let her go to 9600 and never hit a limiter, so I THOUGHT I had an aftermarket chip, but the stamp is ST2 67CA, that's stock right?
-I have a few chips at a friends place I can swap to see if it helps, I can also do the TPS and TB sync there too. What else should I look for? Dirty Injectors, fuel filter? Oh, and its stock pipes too.
2. Second issue is with the forks. Running at all speeds gives a vertical vibration. Bumpy ride, like the pavement is rippled. So bad, that switching bikes, I can see it from 5 feet away. Runout on the tires and wheels looks good, but I haven't taken the wheel off to balance it yet. The forks were set up really stiff. I put everything but preload back to factory, just to feel it. Will know how that works out tomorrow. Oh, the rebound?? The book says 12 clicks out, I can only go 9 out on the right fork??? So I did the left at 9 too. Any ideas on that?

Other than that, she's a great bike!

 

[Bill_Anderson]

None of the ST models run well below 3,000 rpm. See what happens when you keep the revs in the 3,000-4,000 range.

 

[asphalt]

None of the ST models run well below 3,000 rpm. See what happens when you keep the revs in the 3,000-4,000 range.

I understand that, but this is actually dropping a cylinder. Rarely it will continue all the way to 6k then clear.

 

[asphalt]

Oh, and it has new plugs as well.

 

[SS904]

A plug wire, maybe a coil? If it's running good otherwise, I'd think the TB balance and TPS adjustment would be fine. Same for the chip that's installed. I guess maybe a dirty or sticking injector is possible. Run some Star tron through it if you think that may be it.

On the fork rebound adjuster number of clicks. My rebound adjusters (top ones) give 18 clicks of travel. Only reason I can think of for them being less than that would be if someone had the forks apart and didn't set the adjusters up correctly when reinstalling. If you’ve had forks like these apart, you know what I mean...

 

[asphalt]

I'm talking about the adjusters on the fork bottoms, service manual says they are rebound. Odd since I always thought that was compression damping.

 

[SS904]

I'm talking about the adjusters on the fork bottoms, service manual says they are rebound. Odd since I always thought that was compression damping.

Bottom are compression. Top is rebound.

 

[KarlFitt]

check the stearing head bearings too.
That was the issue with mine.

 

[44Dwarf]

Well...not sure but I'd send the injectors out to get cleaned. I'm about to send my ST4 injectors out after seeing how well it helped my GSXR powered race car. It has had a declining power over the past year so i did the normal mant and still was pitifully and lacked and get up and go...off to the chassis dyno showed 33hp....sent out the injectors (sent two set hoping to get two sets of 4) i got back 3 NFG and 5 that were cleaned and flow matched...Back to the dyno after adding a 7 micron fuel filter before the injector rail and were up to 102hp thats more like it!
I used Marren injection out of CT. http://www.injector.com/
Soon as i have time off my Duc ones will go.

 

[latte committee]

A plug wire, maybe a coil? If it's running good otherwise, I'd think the TB balance and TPS adjustment would be fine. Same for the chip that's installed. I guess maybe a dirty or sticking injector is possible. Run some Star tron through it if you think that may be it.

On the fork rebound adjuster number of clicks. My rebound adjusters (top ones) give 18 clicks of travel. Only reason I can think of for them being less than that would be if someone had the forks apart and didn't set the adjusters up correctly when reinstalling. If you’ve had forks like these apart, you know what I mean...

That would be my next step as well.
I had similar issues with my 2007 ST3.
Ran a tank of fuel through it with injector cleaner at double the labelled dosage. ALMOST fixed it. Ran another tank of the same, and good as gold.
During both of those runs I gave it numerous burst of full throttle through the gears to around the 200 kph mark, then shut the throttle to create as much turbulance in the chambers as possible.
I'm starting to get occassional instances of the same problem again, but this time I think it's time for a set of injectors.

Also worth trying ,,,,,, run 91 RON fuel.
Mine runs like CRAP on Premium 98 RON
Runs marginally on 95 RON
Runs best by far on 91 RON.

Fuel brand ,,,,,,
On advice from a Ducati factory trained mechanic, who spent a number of years with the Ducati Superbike Team, I will not run Shell fuel.

If I have a choice I run BP or Caltex.
Since adopting this practice my fueling issues have all but disappeared.

 

[Dr Tom]

Also worth trying ,,,,,, run 91 RON fuel.
Mine runs like CRAP on Premium 98 RON
Runs marginally on 95 RON
Runs best by far on 91 RON.

Fuel brand ,,,,,,
On advice from a Ducati factory trained mechanic, who spent a number of years with the Ducati Superbike Team, I will not run Shell fuel.

Ignorantly I presumed that Premium would be better for my 4S, but I've since read a few times that there will will no advantage for our engines. Does everybody concur?? - will save me alot of money too!!
But thats interesting about Shell! My closet gas station is BP so that's ok, but I'll be wary and avoid Shell from now on!

 

[The Fixer]

Fuel brand ,,,,,,
On advice from a Ducati factory trained mechanic, who spent a number of years with the Ducati Superbike Team, I will not run Shell fuel.

If I have a choice I run BP or Caltex.
Since adopting this practice my fueling issues have all but disappeared.

Can you elaborate on that a bit? I always thought Shell was a decent brand.

 

[ptourin]

When we start talking about brands and octane, remember that we've got guys from several countries contributing to this thread - make sure we're not getting into apples 'n' oranges <g>...

 

[asphalt]

Ok, here's a run down on today's outing.

Fueling, yesterday I did pull the plug on the Chip, verified it was a ST2 67CA. Is that stock? I set the trimmer to mid, since it was all the way rich. Immediately this morning, it was a better ride. No shaking under load, nice, smooth, and better power delivery. BUT, on hard riding, (Chasing some R6) 45 seconds into full throttle and it dropped a cylinder. For the next 2 miles, anything past 1/4 throttle, and it was just one hitting. I pulled off the side of the road, it stalled, I refired it, and boom, back to two. For the rest of the day, it returned to sputter every now and then, usually with a back fire on decel. Previous owner said he had tried injector cleaner.

I'm riding again tomorrow, but tonight I plan on pulling the tank, and seeing the condition of the filter at least. I'll let you know how it goes.

Oh, and for the suspension issue. I too thought the bottom clickers were compression, but the book says they are rebound, and the top are extension. Extension and rebound are the same to me, so who knows. After 9 on the bottom, and 12 on the top, the bike is much more compliant in corners. Pegs on the ground, and it doesn't shift it's line when I hit a bump. The bumping is still there, so next step will be to locate a 22m socket and take out the preload, but I do think the bump is the tire. We'll see soon enough.

 

[jet057]

Can you elaborate on that a bit? I always thought Shell was a decent brand.

,,,Shell,chevron,76 it's all the same,the only change are the cleaners that are put in,each is different.All that go's in to my m/c's is shell cause i like it,no vudu or pigs flying crap.Oh by the way ducati wants us to use shell product's in our bikes hence the shell is a major player w/ ducati.Asphalt do you and that bike a huge favor,Take it to a ducati tech,shade tree guessing will leave you stranded.

 

[asphalt]

,,,Shell,chevron,76 it's all the same,the only change are the cleaners that are put in,each is different.All that go's in to my m/c's is shell cause i like it,no vudu or pigs flying crap.Oh by the way ducati wants us to use shell product's in our bikes hence the shell is a major player w/ ducati.Asphalt do you and that bike a huge favor,Take it to a ducati tech,shade tree guessing will leave you stranded.

Thanks, but I've been building Ducs for about 7 years now. Just looking to see if the ST has anything odd in it, compared to the others I'm used to. I've had dirty injectors before, but they usually clear out with high RPM. I've had bad rectifier regulators, and they usually don't last for 1000+ miles with same symptoms. Fuel pumps usually just go dead. So we'll see where the filter gets me tonight, then if not fixed, I'll move on to the next thing.

 

[pgeller]

Nice bike! You don't see that many silver 00's. Best year for the ST2, really. Generator problem resolved, good Showa suspenders. Enjoy!

I would think that if one cylinder was cutting out, the problem would not be something common to both. And a bad regulator should impact charging, not running. If your battery is staying charged, look elsewhere. I'd be more inclined to look a the injectors and their connectors, a coil (swappable) and its connections, spark plug and wire, etc. Check all electrical connectors for clean pins and a tight fit. Look for a pinch in the harness between the ECU under the seat and the injectors.

Happy hunting!

pg
DD

 

[asphalt]

Nice bike! You don't see that many silver 00's. Best year for the ST2, really. Generator problem resolved, good Showa suspenders. Enjoy!

I would think that if one cylinder was cutting out, the problem would not be something common to both. And a bad regulator should impact charging, not running. If your battery is staying charged, look elsewhere. I'd be more inclined to look a the injectors and their connectors, a coil (swappable) and its connections, spark plug and wire, etc. Check all electrical connectors for clean pins and a tight fit. Look for a pinch in the harness between the ECU under the seat and the injectors.

Happy hunting!

pg
DD

I checked the harness first, thinking at certain RPM a vibration was getting to a shorted wire. Nope. Seems clean. I haven't been down to the injectors though. Since my girl just started riding, I've been running with her every other day. When things get cool, and riding gets less often, I'll do a frame up on her, just so I know I've touched every piece of hardware myself.

I did change the fuel filter tonight with the autozone generic. Easy swap, and I also greased up the o-ring. No damage on it, so I reused it.

One thing I found interesting, is that the mounting of the pump is different to this bike compared to the 916/996. 916's use bolts into the tank, instead of nuts on studs that are welded to the tank. Its nicer the other way around, since they are the perfect thread to push into the pry out holes.

The pump came out with no issues, and went back in just as nice. I did notice on fire up again, that the idle is much better. It was about 900-1000 before, labored a bit, now its 1200. We'll see in the morning if the runout is better all over the RPM range.

 

[flynnmon]

After checking the suggestions above you may want to check crank position sensor. Sounds similar to symptoms I had with '98 ST2, it ended up being a failing ECU. Several models share the same ECU, after building seven dukes maybe you have a spare to swap or a friend with one. Happy hunting!

 

[MarkST]

Ignorantly I presumed that Premium would be better for my 4S, but I've since read a few times that there will will no advantage for our engines. Does everybody concur??

Just regular unleaded.