The Journey is almost Over - Page 4 - Ducati.ms - The Ultimate Ducati Forum
Reply
 
LinkBack Thread Tools Display Modes
post #31 of 55 (permalink) Old Jun 27th, 2019, 9:37 am
Prolific Poster Award
 
Join Date: Jul 2010
Location: Grass Lake, Mi, USA
Posts: 5,487
Images: 4
The screws will affect mixture to at least 5 turns out IME, so rather than play with restricting air flow with the air box youíll be able to get the mixture right by just using the screws. My carby was tuned at sea level in Florida to run smoothly even at just above idle. If the idle hangs , adjust the screws out 1/2 turn at a time . Donít bother with tiny adjustments when the idle is still hanging, youíre too far off. If you go past 5 1/2 turns out, go up a pilot jet size and start over. Remember these are vacuum slides. Your mixture and especially smooth running at low rpmís is dependent on the slides rising smoothly and simultaneously. After confirmation that the butterflies are in synch, with the lid and filter out raise rpmís slowly and make sure both slides are rising together with no dancing around. If they donít, check the diaphragms, slide movement in the bores, and that the diaphragm lids arenít warped/ leaking. The hoses on the air intakes to the diaphragms are prone to collapsing when hot, and the little ďcansĒ get easily clogged. Iíve replaced mine with fuel line and fuel filters.
rwantin likes this.

'96 Ducati SS900CR, '07 S4RS, '06 Busa, '77 Bonny,
'00 Superglide, '85 Sportster, '78 SR500
duc96cr is online now  
Sponsored Links
Advertisement
 
post #32 of 55 (permalink) Old Jun 27th, 2019, 3:44 pm Thread Starter
Senior Member
 
Join Date: Nov 2008
Location: DeLand, Florida, U.S.A
Posts: 214
Garage
Well I talked to Mark @ Factory pro today, I was going to order new needle jets since they did not come in the kit, But suggested trying 1 thing first, I have the floats set @ 14mm -he suggested resetting them to 15mm to get the low end stumble out, said by lowering the fuel lvl in the bowls slightly this very well may solve the issue--I'm going to try this tomorrow if it works great--if not then I will probably order new needle jets and hope that works --I'll let you know what if anything gets this exactly where I want it to be

1991 Ducati 900ss, 1991 Ducati 907ie. 1978 Yamaha SR500, 1979 Yamaha RD400 Daytona Special, 1973 Truimph X-75, 1975 Triumph T-160, 1976 Triumph T140, BMW's too many to list
rennsportmotorrad is online now  
post #33 of 55 (permalink) Old Jul 7th, 2019, 5:46 pm Thread Starter
Senior Member
 
Join Date: Nov 2008
Location: DeLand, Florida, U.S.A
Posts: 214
Garage
Well still screwing around with these damn carbs, on the recommendation from Mark @ Factory pro I have new set my float lvl's @ 15 mm -I have the 40 pilots in, 135 mains & slide needles set to 2nd slot from the top. Now thru all of this the bike has pulled great during acceleration --the only thing that made that worse was I tried to change needle position-then went right back to the 2nd slot --there seems to be perfect. My issue continues to be that @ steady throttle say 4K the bike seems to be too damn rich it stumbles or burbles very lightly. it is rideable but I dont like this. I have tried different combinations stock airbox & modified airbox, I guess the next thing is go back to the 37.5 pilot jetsto see if I can make this damn thing run like I want it to.--More to come

1991 Ducati 900ss, 1991 Ducati 907ie. 1978 Yamaha SR500, 1979 Yamaha RD400 Daytona Special, 1973 Truimph X-75, 1975 Triumph T-160, 1976 Triumph T140, BMW's too many to list
rennsportmotorrad is online now  
 
post #34 of 55 (permalink) Old Jul 7th, 2019, 6:37 pm
Senior Member
 
Join Date: Jul 2018
Posts: 989
i never mess with the float level on these carbs. if the fuel level is right (and i've really not seen one that wasn't) i pay no further attention to the float level.

sounds like it just has worn needle jets to me. but, in saying that, i've got a 750ss here now that has a wacky miss on cruise that i can't work out.

i've also seen a jet carrier that for some reason was bad.

know all wanker
belter is online now  
post #35 of 55 (permalink) Old Jul 7th, 2019, 8:33 pm Thread Starter
Senior Member
 
Join Date: Nov 2008
Location: DeLand, Florida, U.S.A
Posts: 214
Garage
I think I am going to order a set needle jets on Tuesday and just replace the damn things if for no other reason then to rule that out as a problem

1991 Ducati 900ss, 1991 Ducati 907ie. 1978 Yamaha SR500, 1979 Yamaha RD400 Daytona Special, 1973 Truimph X-75, 1975 Triumph T-160, 1976 Triumph T140, BMW's too many to list
rennsportmotorrad is online now  
post #36 of 55 (permalink) Old Jul 7th, 2019, 11:37 pm
Senior Member
 
Join Date: Jul 2018
Posts: 989
that's where i start these days. can't tune around them.

know all wanker
belter is online now  
post #37 of 55 (permalink) Old Jul 8th, 2019, 9:12 am
Prolific Poster Award
 
Join Date: Jul 2010
Location: Grass Lake, Mi, USA
Posts: 5,487
Images: 4
I didnít reread the whole thread so this might be a repeat:
1) You can adjust the needle position less than 1 groove by using small thin washers.
2) These carbs can leak internally and if they are leaking internally you will never be able to get the tune right. If you havenít already, replace the gasket between the needle/ seat block and the main body. Also replace the gasket between the main jet holder and the carb body.
3) If the issue is at 4000 rpm remove the filter lid, start the bike, raise the rpm to 4000 and hold a few times. If the vacuum slides are not rising together, or if they are dancing around when held at a steady rpm, then that may be the problem. Remember, the needles are attached to the vacuum slides. If the slides donít hold steady then the needles will be fluctuating with them. This probably contributes to the needle and emulsion tube wear in that rpm range. If they donít stay synchronized, check the diaphragms, slides move freely, replace the o rings under the caps, verify the caps are flat/ sealing, verify the breather tubes flow freely in both directions.

'96 Ducati SS900CR, '07 S4RS, '06 Busa, '77 Bonny,
'00 Superglide, '85 Sportster, '78 SR500
duc96cr is online now  
post #38 of 55 (permalink) Old Jul 8th, 2019, 9:14 am
Prolific Poster Award
 
Join Date: Jul 2010
Location: Grass Lake, Mi, USA
Posts: 5,487
Images: 4
I see I repeated myself. It happens often at my age. Just ignore me like my wife does.
ifly65 likes this.

'96 Ducati SS900CR, '07 S4RS, '06 Busa, '77 Bonny,
'00 Superglide, '85 Sportster, '78 SR500
duc96cr is online now  
post #39 of 55 (permalink) Old Jul 8th, 2019, 9:38 am
Senior Member
 
bigbadbass2's Avatar
 
Join Date: Aug 2016
Location: Long Island, NEW YORK, USA
Posts: 111
Garage
Quote:
Originally Posted by rennsportmotorrad View Post
I think I am going to order a set needle jets on Tuesday and just replace the damn things if for no other reason then to rule that out as a problem
but in post #12 of this thread (in response to belter asking) you clearly stated you had replaced them

'95 900SS/SP , '07 SS800 . '98 VFR800
bigbadbass2 is offline  
post #40 of 55 (permalink) Old Jul 8th, 2019, 10:06 am Thread Starter
Senior Member
 
Join Date: Nov 2008
Location: DeLand, Florida, U.S.A
Posts: 214
Garage
I was mistaken --like Belter -it happens at my age lol

1991 Ducati 900ss, 1991 Ducati 907ie. 1978 Yamaha SR500, 1979 Yamaha RD400 Daytona Special, 1973 Truimph X-75, 1975 Triumph T-160, 1976 Triumph T140, BMW's too many to list
rennsportmotorrad is online now  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ducati.ms - The Ultimate Ducati Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome