SF1 Misfire

[Paul Marx]

So you have a carb problem as first envisaged.
Does the backfiring disappear if you use a bit of choke when it happens? That would confirm an air leak.
Typically problems like that linked to slides occur near tickover and just above because that's the position where the slides wear the most and after that, the lift of the slide is such that wear doesn't come into play by letting air pass but by letting too much fuel in due to needle and needle jet wear.
Did you change all the brassware and needles in the carbs,
Paul

 

[chrissoz]

Am in UK for a couple of weeks now - has anyone got any recommendations for suppliers of old style PHF 36 slides in UK? I am getting a bit of contradicting information about modifying the new slides for older carbs.
Thanks

 

[Schurminater]

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Classic ,Brembo, Dellorto spares

www.ducatipaddy.com

 

[Rob]

I'm guessing you will have read the info on DucatiPaddy's excellent site https://www.ducatipaddy.com/Slides-Dellorto
The subject has been discussed here too - one example
I've no direct experience of the problem so can't comment on the effect of machining the throttle stop ramp on long term tickover on a twin - not a problem for a triple as Paddy notes. Maybe time to invest in replacement carbs.

 

[Paul Marx]

Am in UK for a couple of weeks now - has anyone got any recommendations for suppliers of old style PHF 36 slides in UK? I am getting a bit of contradicting information about modifying the new slides for older carbs.
Thanks

I doubt that you'll find slides for the older carbs. You'll have to modify new ones to allow them to seat.
I did it a few weeks back. Simple enough.
Paul

 

[chrissoz]

Redax supplied some modified slides (8553 50/3 spec) and new needles and things are going much better. No more misfires, idle is more stable than it has ever been and bike feels like it pulls harder. Result!