Gday. Ive recently purchased an '83 S2 and have been trying to tune up the carbs. On the left carby, I cant get the idle up unless I screw the screw right in, and even then it is just idling. It feels like the slide is quite worn, as I can move it side to side. Is the lack of idle adjustment a symptom of a worn slide and if so can I just replace the slide or does the carby need overhauling? Cheers.
I assume the carbs are Dellorto either PHM or PHF versions? If so, faulty idle can be as you suggest, worn slide; worn needle, worn needle jet, pilot screw incorrect setting, worn pilot screw, failed O-ring on pilot screw, incorrect fuel height, sticky or worn choke. You can get some idea of what's what from Bevelheaven.
The carbs have apparently been rebuilt by the shop I bought the bike at with a kit, but probably not a complete rebuild. Is there some way I can measure whether the slide wear is excessive?
Actually, given that 'older' Ducatis probably didn't do too many miles before they were taken off the road and also both slides usually wear at the same rate (which isn't much - a lot of miles would have to covered before it was noticeable) I doubt your problem is slide wear as such.
Is there anyway I can check that? There is a noticeable sideways movement in the slide, is that normal or wouldn't it cause an issue?
You would need to establish what the original dimensions (i/d) of the carb body slide 'tube' was as well as what the original dimension (o/d) of the slide was. Sorry, I don't know where you can get that info. However, I have only ever replaced one slide in all the carbed bikes I have owned and that was on my Guzzi at around 10,000 miles and that was only because I had OEM open bellmouths and a small stone scored the slide - fortunately it only lightly scored the carb body which I polished out. Maybe yours suffered from something similar and someone fitted a slide from another carb which isn't such a good fit as the original. Perhaps this will help - or ask them the question? https://www.dellorto.co.uk/product-...ttors-dellorto-motorcycle-carburettors-parts/
Thanks for your responses fellas. I've stripped down the carb and given everything a good clean, hopefully it might do the trick ( the vinegar works a treat!!). The idle ramp on the slide all looks good. One part I couldn't remove was the pump jet. The screw undid but neither it nor the jet would come out, is there a trick to this?
Its probably stuck to the O-ring which in turn is stuck in the body. Try carb cleaner or WD40. IIRC correctly you can get something like a thin nylon bristle from a broom to push it out from inside the carb body.
