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View Full Version : Piaggio sfera 50 boging at take off


padly1995
03-07-2015, 02:55 AM
Hy, im fixing my Piaggio sfera 50 2 stroke scooter that i bought. (Sfera has the same engine and frame as Piaggio Zip, only that Sfera has air cooled engine).
I putted in 3 x 8g rollers, so 4g.
There were some holes drilled in exhaust so i welded them and I also removed the blind pipe (restriction). And i also cleaned exhaust by pouring gasoline in it and burning it out.
There is 17mm BGM carb with manual choke and mallosi MHR air filter on scoot.
I dont remember what jet is in, but i think its 55.
Scooter was first bogging alot, than i insterted a piece of water hose in filter.
Now i got to this state. I tried to put some tape over filter but it was even slightly worser.

Now it bogs to 10 - 15km/h but after that speed it goes like crazy.
What is the problem?

And also after i fix that, is it worth to put 2000RPM springs in the clutch?


Thank you

padly1995
03-07-2015, 06:09 AM
Nobody knows?

bull
03-07-2015, 07:49 AM
Two stroke engines, other than lawn equipment, are something I don't have a lot of experience with yet. However, when you are trying to return something to stock or to improve its performance, the best way is to do one thing and test it. Then either accept the change or modify it to continue in that direction until it starts going worse from the last change. Then proceed to the next thing. Not try to do it all at once.

On the rollers you need 6 total, do you only have 3 now?

Holes in the exhaust being welded, increase restriction, removing welded restriction opens it up. Burning out the exhaust MAY cleaned the more liquid portion, but now you have soot- how are you dealing with that?

kz1000st
03-08-2015, 03:17 AM
Bogging is almost always an air leak somewhere. Check for cracked manifold or a leaking vacuum line somewhere. Did you remove the airbox and replace it with some other filter? You may need to up the size of your main jet or adjust the idle mixture screw.

Firehawk989
03-09-2015, 02:41 AM
If your main jet is a 55, that's WAY too small! If it's a 50cc, should be somewhere around an 80 or 82, 84-90 if 70cc.

Firehawk989
03-09-2015, 02:42 AM
Also yes, put the stock airbox back if you have it. The minarelli engines work best with the oem airbox.

padly1995
03-16-2015, 02:31 AM
I removed piece of water hose that i fitted in air filter and it stopped bogging at startup, but then it had bad acceleration and top speed. Strange thing is that i fitted this piece of hose back in and its stil the same. Now take off is good but acceleration and top speed are slow :S

dwint51
03-18-2015, 06:58 AM
ive been running a 80 main but I have a pipe and bbk.the other day I noticed I had a crack so I sealed it up.went for a ride and it was terrible.i had to go down to a 75 and now its better than the 80