Fast idling with Dell Ortos

Post by **Skins** » Mon Jun 13, 2005 8:57 am

I see. Are you not able to do the 'Ducati Cuddle' as I describe it on page 28, to do the slide synchronisation without assistance? That way you could really get it right, because it takes a bit of time and care.

Paul · Post by **Paul** » Mon Jun 13, 2005 9:03 am

I tried that first but I kept banging my forhead on the handlebar.

This way I feel like the little dutch boy with two fingers in the dyke (that could be taken the wrong way...) :laugh:

Paul

Post by **Skins** » Mon Jun 13, 2005 9:14 am

:laugh:

Banging your head on the handlebar? I'm trying to picture it. I don't think I had that trouble. Lets see ... tank off, air filters off, crouching or kneeling on the right side of the bike, left arm over top left side of motor, with finger of left hand in carb off back cylinder, looking into other carb just in front of your face, reach up to twistgrip with right hand? Is that what you tried?

Paul · Post by **Paul** » Mon Jun 13, 2005 9:19 am

Left finger in right hand carb (feeding front cylinder), try to look in to rear facing carb and bash forehead. I see my mistake...

Maybe I should video it and post it here.

Paul

Post by **Skins** » Mon Jun 13, 2005 9:22 am

:laugh:

You should be able to hear me laughing from there!

Paul · Post by **Paul** » Tue Jun 21, 2005 11:07 am

Skins,

Rather than go through the whole sorry saga of what happened when I tried to set up the carbs, you can read it under "I know what happened to my fuel" under the 750 Paso Forum.

Once that was sorted out I followed your steps and the bike started. I then reduced the tickover speed bit by bit, followed by changing the idle mixture. It is pretty close to one full turn out on each side, just like you said it would be. I let her tickover for 15 minutes (which is something that she has never done before) and she sat at about 1,000 revs the whole time. After blipping the throttle a few times she would return to tickover correctly.

I took her for a long ride on Sunday (the first leg was 51 kilometers) and it was lovely that she would just tickover at the stop streets and robots (traffic lights). I stopped for about 20 minutes and filled up with petrol. Some time on the trip back (60 kilometers) she started raising the revs at tickover.

Unlike before, once the first occurance had happened it happened all the time (where as previously it was intermittant). Previously I would let the clutch out slightly with the brakes on to drop the revs, then pull in the clutch again and the revs would remain low. This time is would drop the revs but the speed would increase to about 1,500 when the clutch was pulled in.

It was getting dark when I got home so I didn't wan't to strip off the bodywork and see if the tickover adjustment affects this.

Any other ideas ?

Paul

Post by **Skins** » Tue Jun 21, 2005 8:38 pm

It sounds to me like you're nearly there, Paul.

I'd say that near the end of the trip two things happened: the heads reached full operating temperature, and the carb synchcronisation slipped slightly out of adjustment. The fact that the higher idle is steady now, not intermittent, indicates you are approaching stability in the system.

You should see what the idle is like once she is cold again, to see how much the operation temperature is affecting the idle. But I'd say the main thing will be minor re-setting of the synchronisation. Have you mastered the 'Ducati Cuddle' yet?

Do you have twin throttle cables from the twist grip, or one-into-two? Every moving part in the system from the twist grip to the slides must be snug and tight so as not to slip out of adjustment (except for identical operating slack of about 2mm on each cable where they hook into the slides - some people like more slack).

It is not surprising that you're having to redo the synchronisation adjustment, because we're concerned with very small movements of the slides now, and things may need to settle after adjustment. This is the real 'fine-tuning'. You may even have to redo it again more than once, but the end result of instant response and smooth power is worth it.

Paul · Post by **Paul** » Wed Jun 22, 2005 4:54 am

Skins,

I'll try to get home this evening and start her up and see where she idles. I am going on leave for a week on Friday, so if I don't get to look at her tonight it will have to be the weekend after next.

I did have one other thought. Having stood for so long she was smoking quite badly, even after the 15 minute idle. I guessed that this must have been gummed up piston rings. At my half way point the smoking had stopped. I wonder if there is more sealing happening now, giving more compression and hence more power. Maybe this would raise the tickover ?

Thanks for all the help and suggestions. I will try the "Ducati Cuddle", but if I give myself a black eye I won't post a picture here...

Paul

Post by **Skins** » Wed Jun 22, 2005 6:03 am

I don't think anything contributing to the smoke would affect the idle, Paul. Let's hope the smoking doesn't recur, because it can be annoying.

I think you'll find something in the system has 'settled' after the adjustment, and a little readjustment is required. Remember that after every adjustment of the throttle-stop screws, the slides must be synchronised again by adjusting the cables, using the 'Ducati Cuddle'.

It may well be that she idles faster when she's good and hot. The idle adjustment should ideally be done when she is hot.

Good luck - you'll get there! I'm here for more questions.

Desmo_Demon · Post by **Desmo_Demon** » Thu Aug 31, 2006 12:45 pm

Thanks to this thread, I learned of a problem before it became one with my project Paso. While having the Dellortos apart, I noticed these dimples in the slides, and with this thread, I knew I should file them out. I didn't have a file that size, and wanted to share with you what I found to work.

I ended up using one of my wife's fingernail files! :laugh: I measured the width of the gap in the slide, marked the nail file, and cut it to the width that I needed with a utility knife. This type of file has a course side and a fine side, so it did the job quite nicely. Just make sure that the file is fairly stiff, so it is easier to keep crisp lines and angles when filing. I hope this helps.

qldman36 · Post by **qldman36** » Thu Aug 31, 2006 10:16 pm

Had me worried for your safety for a minute with using her nail file. Then remembered,"her" bike.

ducapaso · Post by **ducapaso** » Fri Sep 01, 2006 6:59 am

Ever mattered about a vacuum balancer?
I'm posting the instructions to build and use it in the F.A.Q. fo paso 750 forum...
I don't mean to make you become skiller mecanics in some hour, but to let you know I became more satisfacted of my dukess' performance!

balancer

Post by **Skins** » Fri Sep 01, 2006 4:13 pm

Good stuff, Nicola, well done! Thanks.

I built something similar once, and it worked OK. I also used water (although I didn't add colour) but afterwards thought that a very light oil may have been better. But perhaps even a light oil would be too sticky in the tubes, and be hard to see.

ducapaso · Post by **ducapaso** » Fri Sep 01, 2006 5:22 pm

thanks to you my friend! I can assure it can perform a very good carb tuning!