Puch E50 round port v square port

I'm working on a buddys maxi and I found it has a 14mm round port intake port cylinder on it. I've never seen a round port before so a Q or two. This is a 77 2hp maxi but it's a replacement engine, should this be a square port or round port?

Re: Puch E50 round port v square port

Either round or square port is appropriate, really. Round intake ports are in the cast iron lined hi-torque, closed transfer type cylinders. By design, the enclosed transfers restrict the volume of fuel mix while controlling the flow for better efficiency.

Square intake ports are for the aluminum open transfer cylinders with the chome cylinder wall lining. Newbs and the uninformed often assume these are crappier than the hi-torque types but, in reality, the open transfers are far less restricted resulting in more free reving high RPM.

Strangely enough, I've found the open transfer cylinders to be more robust and more forgiving to neglect and abuse than the cast iron sleeved closed transfer cylinders.

Re: Puch E50 round port v square port

@schmiddy

Thank you much. I looked for this but I didn't see the hard info.

Re: Puch E50 round port v square port

Jeff,

I post the following link a lot because it is among the most valuable resources you will ever find regarding Puch mopeds. If you cannot find specific answers to any questions you have regarding your Maxi, it will surely have an abundance of clues available in getting you to where you need to go:

https://vintagemopeds.files.wordpress.com/2013/01/puchserviceweb1.pdf

Re: Puch E50 round port v square port

Schmiddy!

That is the best link ever. I appreciate it!

Re: Puch E50 round port v square port

> Jay Rivett Wrote:

> -------------------------------------------------------

> Schmiddy!

>

> That is the best link ever. I appreciate it!

You might fine this page interesting . It contains that^ manual +++ a lot more .

https://drive.google.com/drive/folders/1sRX-Vlezt7eBBaRgPkii1iwazovHbOyr

Re: Puch E50 round port v square port

I have one more Q. This engine has a 14mm port and a 14mm bing but the intake is a 12mm. I know air flow and that is one big ass choke point. did this come with a 14mm intake? thanks for the help.

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