'04 MS4R not idling correctly

[normalcyispasse]

Well, still no luck. I had the fuel injectors cleaned and flow tested. Both passed (rats). Plugged 'em back in, and the bike still idles poorly. For the life of me I just cannot see any vac leaks, though that's what it sounds like I have.

At least compression is good (179/171 f/r).

It might just be time to haul it into a shop. I've been trying for almost five months to fix this problem and it has just eluded me time after time.

[normalcyispasse]

Propane and propane accessories. . .

Monster S4R idling poorly: Propane and propane accessories

Looks like there's a vac leak at the front butterfly vane.

. . . how on earth do I fix this?

[liquidsmile]

First put the ECU trim back to 10 or less

second Zero the TPS correctly

third Sync the throttle bodys at 3K RPM

fourth, set the CO at idle by using the bleed screws- set level to 2.0-2.75 or maybe a little less for your inspection.  should be 4-6 for best performance,

If the HC level is high at this point do a leakdown test

My guess off the bat is that a valve is leaking, either through out of spec or through a valve guide.

[normalcyispasse]

It failed emissions at +8 and passed at +15 but hasn't idled correctly.

TPS has been zeroed very recently, and throttle bodies have been synchronized well. Bleed screws have been similarly set.

Valves have been examined, and all are within spec.

I could do a leakdown test, sure, but it really seems like I've hit on something when the idle smooths out so dramatically when there's propane introduced near the front cylinder (and there only).

First put the ECU trim back to 10 or less

second Zero the TPS correctly

third Sync the throttle bodys at 3K RPM

fourth, set the CO at idle by using the bleed screws- set level to 2.0-2.75 or maybe a little less for your inspection.  should be 4-6 for best performance,

If the HC level is high at this point do a leakdown test

My guess off the bat is that a valve is leaking, either through out of spec or through a valve guide.

[Howie]

You only proved that cylinder is running lean by that test.  Could be a vacuum leak, could be a fuel problem (like a bad injector).  Put a smaller, more flexible hose on that propane torch so you can target different areas like intake runner gaskets and throttle bodies.  Keep in mind some leakage at the throttle shafts is normal.  Or you could go to an automotive shop with a smoke machine and ask them to hook it up.

[normalcyispasse]

You only proved that cylinder is running lean by that test.  Could be a vacuum leak, could be a fuel problem (like a bad injector).  Put a smaller, more flexible hose on that propane torch so you can target different areas like intake runner gaskets and throttle bodies.  Keep in mind some leakage at the throttle shafts is normal.  Or you could go to an automotive shop with a smoke machine and ask them to hook it up.

Can do. I know the injectors are good, though; they were cleaned and flow-tested just last week, and both passed quite well. Since the problem is with the front cylinder, I swapped the injectors F-R to see if the problem would change; it didn't, which leads me to believe it's not an injector issue.

I'll do some more work with the hose today.

[Speeddog]

Valve clearances are as follows (in crap-ass form because I can't get good table formatting to work):

Horizontal cylinder valves      (Control values)      
   Intake      Exhaust   
   L   R   L    R
Openers   0.11 (.05-.18)   0.11  (.05-.18)   0.2 (.05-.23)   0.2 (.05-.23)
Closers   0.2 (.13-.25)   0.22 (.13-.25)   0.16 (.08-.20)   0.12 (.08-.20)
            
            
Vertical cylinder valves            
   Intake      Exhaust   
   L   R   L    R
Openers   0.13  (.05-.18)   0.13  (.05-.18)   0.22 (.05-.23)   0.21 (.05-.23)
Closers   0.22 (.13-.25)   0.23 (.13-.25)   0.18 (.08-.20)   0.18 (.08-.20)

~~SNIP~~

I work in inches, so, converted:

Horizontal cylinder valves         
             Intake       Exhaust   
             L     R     L      R
Openers   .004   .004   .008  .008
Closers   .008   .009   .006   .005
            
            
Vertical cylinder valves            
             Intake       Exhaust   
             L     R     L      R
Openers   .005   .005   .009   .008
Closers   .009   .009   .007   .007

I don't have my database at hand, but IIRC, those clearances don't look good.

[normalcyispasse]

According to the shop manual, all valves are within control tolerances (in the original chart, the values in parentheses).

I work in inches, so, converted:

Horizontal cylinder valves         
             Intake       Exhaust   
             L     R     L      R
Openers   .004   .004   .008  .008
Closers   .008   .009   .006   .005
            
            
Vertical cylinder valves            
             Intake       Exhaust   
             L     R     L      R
Openers   .005   .005   .009   .008
Closers   .009   .009   .007   .007

I don't have my database at hand, but IIRC, those clearances don't look good.

[Speeddog]

According to the shop manual, all valves are within control tolerances (in the original chart, the values in parentheses).

Yes. 

[Speeddog]

For reference, S4 service manual says:

Intake openers: 0.10-0.15, limit of 0.05 (.004"-.006", limit .002")
Exhaust openers: 0.15 -0.20, limit of 0.05 (.006"-.008", limit .002")

Closers: 0.05-0.10, limit of 0.20 (.002"-.004", limit .008")
-------------------------------------------------------------------

I'd go for within the ranges, so IO 0.10-0.15, EO 0.15-0.20, and Closers 0.05-0.10

In general, Ducs don't run well at idle and part throttle with loose closers.

[normalcyispasse]

Are you looking at the S4 (916) manual or the S4R (996) manual? From the S4R service manual:

Opener specs:
Intake:
Nominal: .20
In Operation: .18-.23
Check: .05-.18

Exhaust:
Nominal: .20
In Operation: .13-.18
Check: .05-.23

Closers:
Intake:
Nominal: .15
In Operation: .13-.18
Check: .13-.25

Exhaust:
Nominal: .15
In Operation: .08-.13
Check: .08-.20

For reference, S4 service manual says:

Intake openers: 0.10-0.15, limit of 0.05 (.004"-.006", limit .002")
Exhaust openers: 0.15 -0.20, limit of 0.05 (.006"-.008", limit .002")

Closers: 0.05-0.10, limit of 0.20 (.002"-.004", limit .008")
-------------------------------------------------------------------

I'd go for within the ranges, so IO 0.10-0.15, EO 0.15-0.20, and Closers 0.05-0.10

In general, Ducs don't run well at idle and part throttle with loose closers.

[normalcyispasse]

Here's some info from LT Synder's Ducati Desmoquattro Maintenance and Modification Guide, 3rd Edition:

Ducati 4-valve Recommended Clearances (pre-tesastretta)

Recommended:

Intake:
Openers: .002"-.007" (.05-.18mm)
Closers: .006"-.010" (.15-.25mm)

Exhaust:
Openers: .002"-.009" (.05-.23mm)
Closers: .004"-.008" (.10-.20mm)


I sure hope I don't need to get in there again and adjust valves. That's a SERIOUS pain in the butt. Besides, that also doesn't explain the "sucking" noise on the front cylinder or the flash riding up the throttle body as shown in the video.

[Speeddog]

Clarifying the LT Snyder table, he has a column on the right "My Setting":

Ducati Recommended                                            My Setting

Intake:
Openers: .002"-.007" (.05-.18mm)                          .004" (.1mm)
Closers: .006"-.010" (.15-.25mm)                           .004" (.1mm)

Exhaust:
Openers: .002"-.009" (.05-.23mm)                          .006" (.15mm)
Closers: .004"-.008" (.10-.20mm)                            .004" (.1mm)

I'm fully aware of how much work it is to do 4V clearances. 

The problem may exist elsewhere, but there's baselines that have to be correct so you can eliminate them as suspects.

[normalcyispasse]

While it would be nice to have every valve spot-on, that's just not feasible right now. While I could see tolerances that are too tight/too loose being problematic with stumbling idle or whatnot, that wouldn't explain the flash up the throttle body and it also wouldn't explain the "tsst tsst tsst" sound either.

With none of the valves out of official Ducati spec, I just have a hard time believing that would be a factor that would have to be eliminated right away.
. . . In large part, because JESUS, Ducati, could valve work be any more difficult?

[liquidsmile]

The problem may exist elsewhere, but there's baselines that have to be correct so you can eliminate them as suspects.

Ditto,

and from the video what you are experiencing is called a lean sneeze and it is from the TPS not being set correctly, and the throttle bodies being out of sync/carbon around the plates.

I have an 05 and had this problem. 

How did you guys reset the TPS on this bike? (detailed please)