Dellorto Carb Issue/ Ciao

So i was doing some routine maintenance on my Ciao and decided to give the carb a good'ol clean. I noticed that the screw that goes where the fuel line is came off wayyy to easily and after taking a look at it I noticed that the thread IN the carb was pretty abused. After cleaning the carb I start mounting everything again when I noticed that the screw that goes there is not taking any thread . I went to Home Depot and got the same diameter screw but a tad bit longer to see if it takes the thread better but that didn't work. it looks like the thread is destroyed.

What are my options here? Do I have to buy another Carburetor or is there a way to make a thread (i don't know how widening the diameter of the fuel line can affect the overall performance)

Im horrible explaining things in English so I hope I made sense. Thanks!

PS. the carburetor is a Dellorto 13.13 SHA

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Re: Dellorto Carb Issue/ Ciao

man this picture suck but yeah. the thread inside the carb is busted and doesn't take the screw at all

Re: Dellorto Carb Issue/ Ciao

u might try a standard coarse thread. if that dont work then next size up tap.

Re: Dellorto Carb Issue/ Ciao

Richard Eberline /

that is a 5mm screw, go to a american screw or a 6mm.

Keep the same length. use a dremal tool.

Drill out the inlet hole to size.

tap the carb body to your new size.

tighten only to specs, lightly

Re: Dellorto Carb Issue/ Ciao

Baron Von Hamilton /

Ya^^ Get a cheep tap set. Go up one size and you should be okay.

Re: Dellorto Carb Issue/ Ciao

That is a 5mm screw, go to a american screw or a 6mm. Keep the same length. use a dremal tool. Drill out the inlet hole to size. Tap the carb body to your new size.Tighten only to specs, lightly.

Yes to this. Really you probably wont have to drill for size considering that the threads in there now are stripped out.

If the cheap tap you use is a starter style tap, as in it is pointed, just thread it in partway till you r sure it is staring straight and it is making good threads.

Then remove the tap and snap off the point of the tap so that all you have is the thread.

Doing this will allow the tap to travel all the way to the bottom of the bore and you will have all workable threads.

Be sure to coat the tap with some crisco to help keep from galling the bore.

Re: Dellorto Carb Issue/ Ciao

M6 threads might open up into the fuel passage? I dunno, id personally just try to find another one on the b.s. forum.

Re: Dellorto Carb Issue/ Ciao

I'd just buy a new one if you can find a 13/13.

Re: Dellorto Carb Issue/ Ciao

Baron Von Hamilton /

I have one in the same condition and was going to try the same thing. I think it should work just fine. For a $5 tap you could save a 69$ USD carb.

Re: Dellorto Carb Issue/ Ciao

> Daniel '' Wrote:

> -------------------------------------------------------

> M6 threads might open up into the fuel passage? I dunno, id personally

> just try to find another one on the b.s. forum.

This used to worry me in the past, but nothing bad happens if the fuel touches some threads lol. I have one tapped out to m7

Re: Dellorto Carb Issue/ Ciao

> alex . Wrote:

> -------------------------------------------------------

> > Daniel '' Wrote:

>

> > -------------------------------------------------------

>

> > M6 threads might open up into the fuel passage? I dunno, id personally

>

> > just try to find another one on the b.s. forum.

>

> This used to worry me in the past, but nothing bad happens if the fuel

> touches some threads lol. I have one tapped out to m7

That M7 is the magic . Any other might just be bad JUJU . LOL

Re: Dellorto Carb Issue/ Ciao

Or you can just drill and tap it for a Helicoil and be done with it

Re: Dellorto Carb Issue/ Ciao

sent a PM about buying it from you cause i think i can rescue it.... but honestly, i think you can too... in my experience with at least 3 vespa carbs successfully re-used after stripping the banjo bolts, an M6 the same length and rubber waist gasket on the fuel filter and on the bolt head instead of the fiber rings did the trick, it doesnt have to be cinched as tight because of the rubber and it doesnt cut into nor pinch off the fuel passage and it doesnt displace the brass crown inside the fuel needle seat. to be fair mine were stripped just to the point the stop bolt wouldnt grip well, but they were not like bored out smooth kinda stripped knowhatimean?

Re: Dellorto Carb Issue/ Ciao

Sperry for the late update. So I used a cheap tapper and bored it to M6. Screw fit in perfectly but now the bike doesn't start period. I've cleaned the carb and jets a million times. Going a little crazy here(doing the same thing expecting a different result) .

Prior to having the carb issue and changing the busted belt the bike would start up no problem. Now the pedals are hard as a mother. Im gonna check the compression today even tho that was never an issue before and its not like the bike has been in storage for 10 years. The bike its my daily commute to work.

I think I'm having and issue with the fuel getting to the carb tank but the fuel line is clean and fuel flows out of it no problem. Could be the float? I check the float and it moves fine.

Today ill check the spark plug( I bought it new a couple months ago) , compression. Even bought some starting fluid to see if that does anything.

Questions:

Could the belt swap be the reason for the pedal issue?

I think the m6 screw is a little to long. Could that be an issue?

The frustration is getting to the point that I might just buy a new carb but my hardheaded self refuses to throw in the towel hahaha.

Re: Dellorto Carb Issue/ Ciao

Josiah Radebaugh /

I had this happen. Piece of aluminium got stuck in the idle jet....

Re: Dellorto Carb Issue/ Ciao

That's what I'm thinking to. I got an old guitar pick up that's shot . in stripping that cable to try to give the carb one last clean.

Could the threads on the screw be an issue? I noticed the original m5 screw had threads only by half the screw (hopefully that made sense hahah) and the m6 I'm using now is a fully threaded screw. Could that block the fuel flow?

Re: Dellorto Carb Issue/ Ciao

Looks to me like the fuel would flow around the screw and into the carb body .

I doubt the screw is the problem .

Re: Dellorto Carb Issue/ Ciao

Yeah thats what I thought. Man I'm just brainstorming here trying to come up with a solution. Hopefuly I can make this thing work today

Re: Dellorto Carb Issue/ Ciao

Dirty30 Dillon /

Sounds like crud from the tap job have clugged the inlet.

Re: Dellorto Carb Issue/ Ciao

"stiff to pedal" is the clue, when u changed the belt for the ss clutch. u mighta fu on the spacing direction of washers, take a look at the diagram. id look at that innermost hat washer isnt rubbing againt case causing hard pedal/no start.

Re: Dellorto Carb Issue/ Ciao

awesome. Ill do that. Its a variated ciao btw. Sorry if i didn't specify that when I was explaining the stiffness of the pedals.

Re: Dellorto Carb Issue/ Ciao

Bought a new Carb. Same dellorto 13.13 SHA (the kinetic version so the choke can fit inside the footrest) and I can notice the difference. At least it tries to start now.

Still have the pedal issue . the bike won't start if I run it down a hill and if I try to pedal start it the pedals are stiff like crazy . I made sure the belt wasn't to tight but its not. Took out the variated clutch and noticed its missing the clutch shaft seal(rubber ring ). Can that be the issue. Im out of ideas man.

There's spark in the bike.

Brand new Carb

Compression?! But how does that explain the stiff pedals?

I've worked with motorcycles before but I must admit. This 2 cycle machines are a complete different level of stress Hahahahaha.

Any help is appreciated.

Re: Dellorto Carb Issue/ Ciao

Maybe a clogged exhaust, or a leaking decomp valve.

Re: Dellorto Carb Issue/ Ciao

sometimes the rear 17mm nuts that hold on the gear box get loose, locking uprear wheel, check if those r tight. u just gotta separate/isolate to figure out whats tight.

Re: Dellorto Carb Issue/ Ciao

So the bike ia finally running. Had to bend the frame a little underneath the clutch bell. The belt as not going through smoothly and hence the stuck pedals. Now it pedals perfect .

Thinking of changing jet size.the bike starts fine but it kind of sputters a bit when it finally turns on so I have to give it some gas so it doesnt shutdown.

I noticed it was missing the oil seal from the tranny so I bought one at treats .

Thanks for the suggestions and help guys!

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