need some tuning help!

Post your 'Carburettor & Fuel System' FAQs, comments & questions regarding Ducati motorcycles here.
Post Reply
butcher_79
Cucciolo - the Lil Pup
Posts: 3
Joined: Fri Aug 22, 2014 4:08 pm
Location: United States

need some tuning help!

Post by butcher_79 » Sun Aug 31, 2014 10:28 pm

I have a condor A350, with a Ducati 350cc & vhb27A(d) carburetor, I cleaned the carb with no major problems, but it sputters now like the points are loose, so I removed the cover, the points were closed, so I checked my Haynes manual, it said between .012"-.016" this seems a bit wrong I've tried all, and still sputters, previous owner said .014" and still sputters, changed plug, still sputters, their is some movement of the distributor shaft (or whatever its called) but I'm not sure if that's normal. It moves out when you throttle it, also a snap of the throttle from idle sputters, hunts for idle, starts fine.
I can't tell if its points or carb. I am a former mechanic, but points were never my specialty.

User avatar
Craig in France
Cagiva Gran Canyon
Posts: 871
Joined: Tue Mar 23, 2004 3:58 pm
Location: Montpellier, France

Re: need some tuning help!

Post by Craig in France » Mon Sep 01, 2014 8:50 am

Starting (pun intended ... :) ) with the ignition:

1. The correct points gap is 0.3-0.4mm. Or 12-16 thou, to yous Americans :-D . (You don't need to be super, super accurate - any variation within the range just adjusts the ignition timing a teeny-weeny, little biddy bit).

Next, do the obvious:

2. Make sure the plug lead is properly fitted in the coil, that the plug lead is clean and that the plug cap is in good condition and well attached to the lead (if it's a screw-in type, take it off, cut back the lead ¼" and refix the cap).

3. Also check your coil connections - all clean and well attached.

4. It could also be that the capacitor (aka condensor) is failing. Lots of info on Internet on how to rough test a condenser, e.g. http://mgaguru.com/mgtech/ignition/ig129.htm

... or just replace it anyways (you should always carry a spare, btw).

On the fuel side, can you be more specific about WHEN it splutters, i.e. does it do it a particular throttle opening? I'm not quite sure what you mean when you say, "a snap of the throttle from idle sputters, hunts for idle" . Do you mean the engine falters when you open the throttle quickly? It would also help to know what jets and slide the carb is fitted with, and what condition they're in. Have you changed any?

Post Reply

Return to “Carburettor & Fuel System Shop”