Condraticing Tuning information 2T 70cc

[freccetta]

Hi Everyone,
I need some help here in fine tuning.

Here is my setup:
Piaggio Zip 2T (2011)
70cc Iron Malossi kit
Dellorto 17.5 carb
Needle second from top
Main Jet 82
Pilot 32 (original)
Rollers 5.7g
Malossi Carbon Reeds
Exhaust Tecnigas Next R
Malossi Red filter Single Layer
Original air box (snorkel removed)
Choke Manual


Issue:
When I initialy get on the throttle I have an instant of splutter( rich) it then immediately clears and I rev and run fine.
It suspected air-screw becuase running rich at idle. I have turned it out 3 1/3 turns and this seems to have solved the problem. But I was reading that 3 1/2 tunrs out is to much. Is this correct?

The reason I have it that far out is becuase otherwise I seem to not have the correct ar/fuel mixture. I could down size the pilto jet but that also sounds wrong becuase I'm already running a small jet (32 original one). I could also try and lower the needle even more but that would mean putting it on the highest position (at the limit) and will effect my 1/4 to 1/2 throttle response.

Additional info that may help:
I have a maunal choke that is always off. I live in hot place and never need choke to start.

When I turn the air screw back in, let's say 3 turn out, the scooter start but runs really bad for about 2km before it is fully warm and still splutter on initial throttle.

I have attached a photo of my spark pluge after about 200km running. I think I might be a little on the rich side. I could down size the main jet but theoretically that should have no impact from initial throtte to 1/8 ?

With the air screw that far it out also mean return to idle is a little slower. If I have the air screw and 2 1/2 turns out the return to idle is better but the spluttering is back.

 Any ideas?
 

[aeroxbud]

You are running a pretty big jet for a zip. Isn't the standard jetting on the stock main only a 53?
That's an increase of nearly 55%! Most only go 5-10% for a sports kit. Then Perhaps another 10% for a high end exhaust. The next R is a basic sports pipe.
Does it work ok if you ease into the acceleration? Or do you always get it no matter how slowly the throttle is turned?

[freccetta]

Dec 2, 2023 21:01:20 GMT -5 aeroxbud said:

You are running a pretty big jet for a zip. Isn't the standard jetting on the stock main only a 53?
That's an increase of nearly 55%! Most only go 5-10% for a sports kit. Then Perhaps another 10% for a high end exhaust. The next R is a basic sports pipe.
Does it work ok if you ease into the acceleration? Or do you always get it no matter how slowly the throttle is turned?

Correct. Stock was 53. With exhaust and  Malossi red filter I found 62 to work best.

Now I have added the 70 kit.

Yes, even when I ease into the acceleration is still does it. Obviously less but still does. With the air screw 3 1/2 turns out it seems to be ok. I'm just concernded that it is too much. I read the ideal is 1 1/2 - 2 turns out. 

It doesn't seem like 82 is big looking at the plug. I believe you have the maths wrong it is a 35% increase from stock.

[aeroxbud]

You could try the original filter again. Did you oil the Malossi filter before you used it. That's what I have in one of my bikes, and they don't work correctly without oil.

Main jet calculation 82 - 53 = 29 Then: 29 / 53 = 0.54717 Then: 0.54717 x 100 = 54.71698 - showing a 54.71698% increase.

[freccetta]

Dec 3, 2023 4:49:29 GMT -5 aeroxbud said:

You could try the original filter again. Did you oil the Malossi filter before you used it. That's what I have in one of my bikes, and they don't work correctly without oil.

Main jet calculation 82 - 53 = 29 Then: 29 / 53 = 0.54717 Then: 0.54717 x 100 = 54.71698 - showing a 54.71698% increase.

I did oil the filter...but you are are correct it does seem like 82 is too much. Did you see my plug image? Doesn't look bad does it?

You think I should go down by how much? Maybe try a 78?

[aeroxbud]

Could give it a try. The plug is very rich round the ring.