Carb Issues with 35mm Cone Filter

[Joecot]

Hi Guys
I bought a used Vento Zip 3ri Turbocam that had the stock airbox/filter removed and replaced with a 35mm cone type high flow filter. The engine runs great at idle, but when I open it up, it stalls, sputters and wants to die! I am thinking that it may have to small a jet in the carb. I think the stock jet is an 80, but not sure. Is there anyone that has taken the stock air box off and added the cone fileter? If so, did you reject or what did you do? I am thinking of trying a 90 size jet.
Please let me know.

Thanks
JC

[j~scoot]

a 90 would be a good place to start. you almost always need to upjet when going to a free-flow filter. I'd change the jetting before riding it around more as you are lean and could damage the engine.

[fakinventobrah]

Yup 90mj is good, but is the rest of the bike stock? If so your better off using the stock airbox, running just a open filter will add no power, it will only add noise and waste gas.

[na96ek]

just a heads up. I have an 06 Zip R3i that I just bought an open filter for and ordered an 87 jet from provo thinking the stock jet was #80. When Everything got here and I went to take the bowl off of my stock scoot I see it actually as a #70 main jet!!! I went an put the 87 in but it was wayyy wayy wayyy too rich. Im going 77 on the main. Will keep you posted, im pretty sure the manual has a misprint with the #80 being stock.

[Bachadaboy]

prolly all of them everywhere in the world are 70 mine is anyway

[X7rocks]

dont just switch the main jet...what good would that honestly do with the revs? switch out the pilot aswell....