General thoughts on Carbs

[Alfonso70]

Hola everyone,

I was reading a copy of Practical Sportsbike recently and they were talking about restoring 90's sportsbikes in general and said "obviously the carbs will be worn out and you should budget for replacing". This got me thinking because my beautiful Morini is now nearly 37 years old and admittedly when i rebuilt the carbs a few years ago i did fit new jets, needles etc, but i do wonder what i would do if i needed to replace them! Maybe someone has already thought about it and has a solution, or maybe i'm just worrying over nothing, are Dellortos better made and therefore don't wear out as quickly!!

Just wonder what peoples thought were really?

Cheers

ps over here in spain classic bikes are very limited - mainly spanish built single Desmo dukes - but on a trip last year to some bonkers road racing i did notice some stunning Morini's racers. Sadly i'm no David Bailey so could not get any decent photos of them, but this year i will make an effort to scourer the paddock for them and get some photos and info.

[Steve Brown]

Hola Alfonso, I think it depends more on which type of carbs you have. All the older 'flat' slide carbs I have here are well worn, most of the round slide types I've seen were standing up well to use. Hence my looking for a pair of decent low mileage carbs in the ad section. You can still get new Dellortos of course, so if you're worried maybe stock up on them now
Maybe I should offer to swap my spare L5 cam for a pair There's still time to fit it before Cadwell

[trinder]

Maybe I should offer to swap my spare L5 cam for a pair There's still time to fit it before Cadwell

You silver tongued 'Diablo" Steve,
You already talked me into buying a Morini (not that needed much encouragement) and now you dangle a tweaky cam under my nose 'Oi mi cojones'

Tommy

[EVguru]

Square slide Dellortos are somewhat noted for wear. The slide is quite a loose fit in the carb body and can rattle about (probably why Morini changed to rubber inlet manifolds). That's why it has quite a strong spring and the spring seat angled to keep the slide biased to one side to seal properly.

The carbs on my Sport have quite a lot of wear in the slides and It runs very nicely!

Putting on a pair of new round slide carbs wouldn't gain me much, but I could spend a lot of time getting the engine jetted so it's as good as it is now.

I'll wear out what I've got and then consider a replacement.

[Steve Brown]

Paul, that's interesting, I might even try using these sloppy old carbs I have. It certainly would be cheaper.

[EVguru]

I've considered facing the slides and adding a low friction strip.

If I ever get short on carbs, I may give it a try.

[Daddy Dom]

Post ultrasound-clean, just fitting a humble service kit to mine was something of a revelation! I also lowered my pilot jet down to a 45 which made it run a lot smoother when opening up.
Cheers,
DD

[Alfonso70]

Sadly it appears that the flat sided carbs are no longer available new. I also note from the website that most of the slides are now discontinued. Sorry to ask a dumb question but is it just the slides that wear out rather than the actual carb body?

[HoveActually]

Have a look at this web site - some parts still available for some carbs!

http://www.dellorto.co.uk/merchandise/p ... ctionID=68

[3potjohn]

Bonos dies Alfonso
hope you are enjoying things in cider country. Did you mean the la Baneza races? I have been trying to get to this but cannot get time off work.
Slide carbs are a bit of a problem wearing out.I have slide carbs on a BMW and at least can get spares,though this is getting more difficult.I think that bikes running no air filters probably risk more wear. I rebuilt my carbs and they seem OK but have no answer if the carb body wear out.
John

[EVguru]

Sorry to ask a dumb question but is it just the slides that wear out rather than the actual carb body?

The slide wears more than the body becuase it has a smaller area.

I think it may be possible to cut the sliding face in the body to straighten it up, but good second hand carbs are not that difficult to find.

A worn slide is most likely to cause an inconsistent idle and low throttle balance problems. Not the most serious of issues as far as carb problems are concerned. I'm fussy about low throttle flexibility and I've yet to scrap a carb becuae of wear. I have scrapped a couple, but It was always because of some internal passage problem that cleaning hadn't cured. Internal problems can be really difficult to find, perhaps one day I'll rig up a wet flow box for carb testing.

Have a look at this web site - some parts still available for some carbs!

That's 'the website' that we've been mentioning. They have a small and deminishing stock of parts for obsolete carb types. Needles and atomisers of certain types are NLA which is a problem as they are often corroded if the bike is left standing for some time. Propping the slides open is a good idea for a long lay-up.

[Daddy Dom]

Italian ebay is also a potential source for some interesting things. Somebody was scrapping a sorry-looking triple-disc K for parts when I looked yesterday. Maybe you could score the carbs?
Dom