ducatipaso.org

imho better stick to the paper gasket. Liquid sealant (i.e. Hylomar) is fine when it gets in contact with oil but if it`s gasoline it will soften and dissolve over time.
There are probably other heat resistant sealants that can cope with that.

G.

Throttle shafts have been known to leak past bearings,I have not had this problem myself,and have not dismantled mine so I'm not really sure if there is a seperate seal or if they just use sealed bearings ?
I think that I read a post from someone who replaced theirs some time back,a search of the forum may find it.

It was just a suggestion as it appears that you have an air leak,by the number of turns required on the idles, and I'm running out of other ideas.

Does anyone know if the 44dcnf112 has the same float level as the 44dcnf107 ?

I doubt that they would be different but you never know

You are setting the idle mixture screws with the engine hot aren't you ?
This shouldn't cause much of a difference though.

The 56 idles are too lean but I'm not sure why.

If you can't find any other leaks,you should go up in idle sizes until you can tune to about 2 1/2 turns
without the engine misbehaving.

Hope you can sort it soon. J.

J - I'm starting to wonder if maybe there is something different with the California models. I'm having the same issues as Brutus and I've replaced my carb (If you remember mine had a crack at the AF screw in the venturi) with a good working one. I'm now at;
- 170 Main
- 185 Air
- 60 Idle - I had to use the 60 idles as opposed to the 57's because I was getting a stumble between idle and when I would get on the throttle.
- Just under 1/4 turn open on the air corrector on the vertical cylinder
- Both A/F screws around 4.5 turns out.
- I made myself a small measuring device that I put into the main jet tube to measure fuel level and it's about 2mm below the venturi openeing when my float is set at 44mm. I check this with the fuel pump running.

The bike has run the best it's run yet with no pops. Oh, I'm also at about 1800 feet above sea level. Also, I just had the valve adjusted and new belts put on.

Just to make sure we're on the same page here's how I do the adjusments;

1) Start with the base carb setting of 2.5 turns out on the AF's and throttle stop 1/2 turn in from touching.
2) Turn choke on full, bike starts no problem and let it warm up to operating temp. (Choke cable is properly adjusted as well)
3) I have one of the good quality vacuum meters that goes in the top of the carb (I've used it for awhile to adjust the Dellortos on my Porsche so I know it works). While the bike is idling I match the lower vacuum venturi level to the one that is higher by opening the air adjuster screw. I also run it up to about 4500 RPM and compare venturi's to make sure airflow is correct and stable.
4) Bring engine back to idle (around 1200 rpm) and start opening one of the AF screws until the engine starts to rev up.
5) continue opening until the engine again starts to miss. Close the screw down until engine starts to drop in speed.
6) Open screw back up to where the engine is happiest between the two extremes.
7) Do the same process with other AF screw.
Readjust idle to 1200 RPM
9) Repeat the process to get finer adjustments.

I will also rev the engine occasionaly in the process just to "reset" the carb.

Yes Ahdoman,I'm starting to think the same thing.It is webers own recommendation that if you have to open the idle much more than 2 1/2 turns that you should upsize the jet,but we were assuming the damage to the seat was causing the problem.Maybe not !

From memory I think that Jfiore also runs 60 idles on his bike,maybe that is a Californian model too ?

They ran ok in my bike, but once hot,there was too much backfiring on the overrun.

Maybe Jfiore's settings are a better place to start tuning the California models (if his is Californian,that is !) They can be found earlier in this thread.

There's a bit of anti pollution gear fitted to them from what I've read,so maybe they run leaner for pollution reasons ? but I thought that they still ran 57 idles as stock ? and should still tune properly
with the 57's fitted.

The mysterious weber will eventually yield it's secrets.

Yes that is exactly how I tune mine except I take it for a good run (with the oil coolers and top fairing zip tied on) and then readjust the mixtures while hot,before reassembling the lower fairings.

You may be better trying Ahdoman's new jetting Brutus.

Disconnecting the pollution gear may cause the problem ? just another thought. J.

No, my bike is not a California model. I just found (at least on my bike) that the progression circuit operated more smoothly, and there was less lean hesitation on small throttle openings when the 0.60s were used. However, my idle mixture screws are almost 3.25 turns open. When I tried 0.57 idle jets, the mixture screws had to be 3.75 turns open to get a good idle and start-up, and there was a bit of lean hesitation.

The only way that I could get 2.5 turns on the idle mixture screws was with 0.65 idle jets, but there was noticeable bog at the start of the progression, before the mains got involved.

I will caveat those statements by saying that I never checked for air leakage around the throttle shaft, although I checked all of the external connections and idle jet O-rings for leakage.

Got it!




First I've used threebond liquid sealing on the manifold gasket. It's gasoline resistant and easy to use cause of a special nozzle. Furthermore I used allot of grease on the bearings, so any previous leakage should be fixed for one testrun. Guess what.. No difference..

As a last resort I had another go on the modified cam. Whattayouknow: with a stock cam the lean spot at 3k was gone..! Below the modified cam I used the whole time:



Now I've fitted another cam from webcon UK, without modification:



Runs ok. No spitting / banging from the exhaust. Allmost no stumbles after a warmed up engine, my setup:

• K&N oval airfilter nr 56-1120
  open laser exhausts
  185 AC
  165 mains
  56 idles
  square diaphragm cover pivot hole number 1
  air bypass screw: vertical cilinder 1/2 out, horizontal closed
  idle mixture screw: 4 turns 360 degrees out (both)
  float level: 45mm
  unmodified pump cam from webcon

Not absolutely sure about the cam. Jay, you've altered the height of the cam till 4mm of difference between top and start position. Is there a reason why this should be approx 4mm? Is the standard height of the webcon cam to much?

Léon

Great news Leon, For whatever reason your setup was lean ,and required the extra fuel from the pump cam to run properly.Perhaps slightly too much was removed from the cam.
Changes to the cam, should not really effect the backfiring or popping at idle or on the over-run ,as the pump only works on acceleration,so I think something else must have also been fixed ?

The main modification on the cam is in the first flat area before the ramp starts,the reason being that the stock cam supplies too much fuel at this point ,causing a rich miss when taking off and at lower revs when applying throttle.This miss becomes more pronounced when the bike is fully warmed up ,and is hardly noticeable while the bike is cold and warming up.

The rest of the ramp effects the richness of mixture in the moments after this point of acceleration,and the stock cam seemed to be fine once past the lower revs so I stuck roughly to their profile,seeing no reason to add any extra fuel than needed,(as this seemed to be the main problem).

If your bike is running well like it is leave it alone,but if it feels a little lazy on hard acceleration,the aggressive cam will likely be the reason.

After you have been riding it a while you will get a feel for how it behaves hot and cold and should be able to tell if you need a little off the ramp or the start of the cam,but if you are happy with it leave it alone( if it aint broke,don't fix it).

I think that riding the bike for a while ,and getting a feel for the issues ,(if any), is probably a good idea for anyone contemplating messing with their weber.As they then know what the
stock setup feels like and can more easily judge if the changes being made are beneficial or not.

Hope you have a blast riding it,nothing sounds quite like a webered paso getting a workout J.

Gents, after the winter I've encountered another problem. The bike wouldn't pick up as it supposed to and there was a stumble around 3500rpm. Starting the bike would last forever, but when fired up it would run idle at approx 1000rpm. While driving at 4k rpm and pulling the clutch it would stall. A bit of banging and spitting.. So I changed the cam and the idle jets to 57. A lot of banging, slow pick up from idle and stalling again.. Bike in the shed, pulling my hair. After a couple of weeks I've had another go at it. Only to find out the battery is dead. A long story short >> new battery, 56 idles again, some different idle jet screw settings and this is how she runs today..:

https://www.youtube.com/watch?v=AtcmdXrRJn8

Beautiful sounding Weber! Beautiful Paso as well.

randtcastell wrote:Beautiful sounding Weber! Beautiful Paso as well.

Thanks allot. I'm allmost there with the setup of the Weber. Great equipment once it's working properly.

Good work Leon, sounds great ! J.

jayh wrote:Good work Leon, sounds great ! J.

Having allot of fun with the Weber, tx to the information I found on this topic. I was wandering what kind of air-fuel meter you were using earlier. I'm considering to buy a LM-2 and have a go on a second dcnf. Preferably in combination with a selfmade spaghetti exhaust system. Bought a TIG welding machine last week.. Now I have to collect some old piping and then it should be possible. Jay again tx

LM-2 will do just fine. I used an LM-1 Tracking is very helpful. RPM is useful and so would throttle angle

I used the LM2 ,great unit,only problem I found was it occasionally hung,or froze, requiring a disconnect
of the power to get it going again.Not sure why it would do this,but it was only when I had the rpm signal going in ,maybe something to do with the variable resistor that I wired in to get it all working ?

There is a small amount of stuffing around when you start monitoring extra signals,ie rpm, the raw signal,depending on its strength and type,may need to be buffered for the LM2 to recognise it.full instructions come with the unit and it's not rocket science,just not necessarily plug and play that's all.

Anyway I would still recommend it,as this was the only problem I experienced and the software that comes with it is easy to use and offers plenty of features to view and compare the data you gather.

An SD memory card plugs into the top of the unit allowing you to upload data quickly to your computer.

Keep us posted on your results. J.

Ok, it has been a while. Last couple of weeks I'd another go at the setting of the Weber. This time I'm going for a more 'scientific' approach.. First thing is to get all the LM2 stuff installed to get an idea of the current airfuelratio. I've welded the dung on the vertical header for an easy installation of the O2-sensor. Did I mentioned I've put on new NGK spark plug wires earlier? These red sillicone ones don't work well with the LM2 clamp.. After ordering and installing the analog-cable (black/white wire on negative position coil) it works fine for a stable readout of RPM.