Page 1 of 7

Vespa PX 221 help

Posted: Tue Dec 02, 2014 3:13 pm
by Nik221
Hi everyone i need help with tuning my engine iv got a few problems. I have a malossi 210 mazzuchelli 60mm crank with 1,5mm head distancer, phbh 30mm carb with polini manifold and ramair filter, malossi 4-plate set with xxl springs and thw clutch has a ring welded, polini rh exhaust, lml 2200g flywheel, DRT 24 teeth on clutch.
The problem is that it wont idle even with the idle screw all the way in it goes great at higher revs but i am not pushing it until i run the engine in. The ignition is set at 17 degreas BTDC. Other than the idle problem is that it starts a bit harder aswell before i did the rebuild a few weeks ago it would start at first kick cold or warm with or without the choke, but know it is hard. Tried various main jets, with and without air filter, the needle on al the slots but still the same even screwing the air mixture doesn't help. I tried to put the standard carb back just with bigger jets and it was the same thing. Also when i give full throttle it starts to bog and turns it self of. Hope its nothing seriuos since i have just finished rebuilding the engine. Please help with some ideas and advice. Thanks in advance !! :)

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 6:01 pm
by lockman69
Change the pilot jet if the mixture screw is having no effect on the tick over/idle, bogging at full throttle and not clearing, sounds like your running too rich/big on the main jet, shouldn't be cutting out unless your not getting enough fuel through the carb, you might need to fit a fuel pump or maybe you have an electrical fault ?...Ive always run my 210's at 16' BTDC, but I dont think your timing is causing your issues...good luck

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 6:10 pm
by sean brady scooters
check your fuel flow from the tank to the carb ,you should be getting about a pint per minute to be safe ..

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 6:31 pm
by Nik221
My jets are pilot 55 main 115 choke 70.
The plug is always wet whenever i take it off.

Cheers! :)

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 7:11 pm
by Spanish Fly
Nik221 wrote: it starts a bit harder as well before i did the rebuild a few weeks ago it would start at first kick cold or warm with or without the choke, but know it is hard.
What do you mean? Is it physically hard as in stiff? Or just reluctant to start?

SF

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 7:31 pm
by wack 63
Has your flywheel got 2 keyways?

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 8:55 pm
by Nik221
Spanish Fly wrote:
Nik221 wrote: it starts a bit harder as well before i did the rebuild a few weeks ago it would start at first kick cold or warm with or without the choke, but know it is hard.
What do you mean? Is it physically hard as in stiff? Or just reluctant to start?

SF
No im sorry i meant it starts as in reluctant to start. :)

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 8:56 pm
by Nik221
wack 63 wrote:Has your flywheel got 2 keyways?
No it has one. :)

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 9:08 pm
by goldeneye
your not a million miles out on the jetting (a bit lean on the main , but pilot is ok) so I"d look elsewhere nik , coil , or stator etc, woodruff key ok on flywheel? keep at it , nice scoot that Faro Basso as well.

Re: Vespa PX 221 help

Posted: Tue Dec 02, 2014 9:16 pm
by Nik221
goldeneye wrote:your not a million miles out on the jetting (a bit lean on the main , but pilot is ok) so I"d look elsewhere nik , coil , or stator etc, woodruff key ok on flywheel? keep at it , nice scoot that Faro Basso as well.
I will thanks, i have noticed that it uses around 6 liters to 100km wich i think is too much, i know a friend from germany who has the same setup exept he has the original upjetted carb and uses only maximum 4 liters per 100km. So its a wierd problem. And thanks for the faro basso, we have 3 ( one from 1948 bacchetta,1953 faro basso and the 55' you have seen) :)