Malaguti Commuter

Dan /
hal2010
Aug 13, 2005 11:58PM

Hey

I lost my last post some how so here it is again. I have a 1977 Malaguti commuter which needs Dellorto carb jet SHA 14 (12). Someone was good enough to show me to a web site for these jets but I don't understand# 44 #45 #46 etc .What would the actual number be for the required jet. Any help on this one is great. The moped runs but not steady. to much gas is geting to the carb. (After cleaning the jet. Honestly I runied it !!) It sat for 15yrs in a garage and was given to me. It is nice looking . I'll have to post a picture of it. Also does anyone have history on a 1977 Malagutis

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Re: Malaguti Commuter

Joe Woods /
joew
Aug 14, 2005 12:15AM

if you wanna mess with it, someone recently had good luck with a little trick .. A very thin, "C" shaped stainless steel wire is threaded through the main jet. This restricts fuel flow slightly, leaning the air:fuel mix. The "C" shape secures the wire to the jet.

but before you go in the direction of a different jet, make sure you're reading the plug-chop correctly and that nothing else is wrong.. like air-intake restriction (which will also make it run rich) or a vcuum leak or fuel leak which can cause weird symptoms.

And if performance sucks below 3/4 throttle, the main jet is not the problem.. It could be a high float level or a leaking float needle, or slide-needle adjustment.. or similar..

Main jet size determines max fuel delivery only near wide open throttle.

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Re: Malaguti Commuter

Dan /
hal2010
Aug 14, 2005 12:23AM

Very cool I would have not thought of trying that

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Re: Malaguti Commuter

Dave Mcgarry /
cyberian
Aug 14, 2005 07:43PM

"if you wanna mess with it, someone recently had good luck with a little trick .. A very thin, "C" shaped stainless steel wire is threaded through the main jet. This restricts fuel flow slightly, leaning the air:fuel mix. The "C" shape secures the wire to the jet."

joew -

I'm not syre that I'm following this. Where, exactly, does this wire go? Not in the jet orifice I imagine.

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Re: Malaguti Commuter

Joe Woods /
joew
Aug 14, 2005 09:04PM

yes.. right inside / through the orifice.

Since the jet's orifice is tiny, the wire has to be really tiny.. Calculating the square area of the jet hole and that of the wire, you might get close to estimating how much area is cut off.. and extrapolate how much fuel is cut off. But i'd bet that's just wishful thinking..

There are too many influences on fluid flow through an orifice aside from the hole's open area for it to be that simple.. Accurately estimating how big the wire should be (or how many small wires to use) is a job for the fluid dynamics guys at MIT.

I'd just be careful.. start with a single tiny wire.. plug chop.. read the plug carefully..

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