Vespa Polini 65cc Port Question

joe Woytasik /

Just received my 65cc Polini kit and dont understand the W port in the cylinder. Could someone explain it to me?

Here is the kit I got from Fred.

http://www.treatland.tv/vespa-piaggio-polini-64cc-43mm-kit-p/vespa-polini-43-12-140.0065.htm

Re: Vespa Polini 65cc Port Question

the two bases of the 'w' are the inlets for three boost -style ports, the two inlets on the cylinder, match up with a cut-out on the piston. They're just like boost ports in any other cylinder, except they match up to a piston cut out, not case transfers.

Re: Vespa Polini 65cc Port Question

So nothing special needs to be done while case matching correct?

Re: Vespa Polini 65cc Port Question

So I went and looked at my cylinder and the W port is confusing the hell out of me. I know I need to match the main transfers, but do I need to cut 2 new transfers for the w port? See the attached pics as my gasket did not come with those areas cut out. I am unsure on what I need to do, take a look at my picture and let me know. If anyone has pics of there installs that would be very helpful.

Pic 1 without gasket

1246311856_img_0513.jpg

Re: Vespa Polini 65cc Port Question

Pic 2 with gasket

1246311886_img_0514.jpg

Re: Vespa Polini 65cc Port Question

I'd match them. If you look at polini cases, they have matching transfers for those ports.

Re: Vespa Polini 65cc Port Question

got any good pics of a polini case with the transfers?

Re: Vespa Polini 65cc Port Question

Re: Vespa Polini 65cc Port Question

i have my case together but this is what my base gasket looks like for a 42mm polini kit

1246405371_img00513.jpg

Re: Vespa Polini 65cc Port Question

match the gasket to the kit, and use it to transfer the shape to the case.

Re: Vespa Polini 65cc Port Question

Does the Polini speed engine case work with the 43mm 65cc kits?

Re: Vespa Polini 65cc Port Question

four shore

Re: Vespa Polini 65cc Port Question

Here is the response I received from treatland regarding the case.

Hi there-

These kits really only work for 46 kits... the spacing would be weird if you tried to use it with a 43mm kit unfortunately... sorry man!

I dont know that it will work with a smaller kit. If I go that route I think I will need to upgrade to a 46mm kit.

Re: Vespa Polini 65cc Port Question

i have the same case and have used it with a 41mm kit and 42mm kit the ports lined up almost perfect for me.

hmmmm mine seems to work pretty good but the ports on my 42mm kit are probably bigger than the 43 mm polini kit

Re: Vespa Polini 65cc Port Question

If you used the speed engine case with a smaller kit wasnt there alot of slop around the cylinder skirt? If the bore will fit a 46mm kit, then I would have 3mm gap all the way around the cylinder. Wouldnt this gap disrupt air flow and make for worse performance?

Re: Vespa Polini 65cc Port Question

i am running the speed case right now with a 42 mm polini crazy port aluminum kit and it works great ive hit 53 on it so far there is no slop or wiggle of the piston skirt at all and the ports match good but that is with my crazy ported kit i also have used it with a water cooled kit and everything fit well in it and it ran great

Re: Vespa Polini 65cc Port Question

also this is from the assembly instructions that polini gives you with the case "the crankcase can be used to assemble whether original cylinder or increased cylinders: piston D.41-43-46."

Re: Vespa Polini 65cc Port Question

Did you cut your crank according to polinis directions? What's the low end like? I might order the speed engine case, probably 1000 times better then anything I could do with a dremel.

Re: Vespa Polini 65cc Port Question

i did cut my first crank but proceded to shear it so i pout it together real quick with a crank i had laying around and it has one thats not cut right now but the case is really good the ports are huge and the only way you could get them that big is with a lot of jb weld and a stock case or the speed case.

low end on the bike wit the cut crank was good even single speed withouth the cut crank not so much

Re: Vespa Polini 65cc Port Question

Am I better off selling this kit and moving up to the 46mm kit? Is the 70cc kit going to be leaps and bounds faster.....or just a little faster?

Re: Vespa Polini 65cc Port Question

the 70 kit is like 5 horsepower if i remember right i only have a 42mm kit but that thing has a ton of power but if i ever break it im going to go bigger so i woud say go big

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