Top speed to expect from a Puch e50 stock top end?

David McHugh /

Just got done rebuilding another e50. I was about to through a k-start 50cc on it, and it occurred to me that I never try for max performance, even in a kit. I'm talking close to stock setups mostly. Chuck a 15mm intake and one of those stock looking aftermarket cigar exhausts, upjet until I hear four stroking, and I get about 35ish. I generally run things a bit rich. Let's pretend that I care about high performance for a second and I tune it accordingly. How much more performance can I squeeze from this basic setup? More to the point of this topic, all else being equal, what is the most I can expect from a stock 2HP top end?

Re: Top speed to expect from a Puch e50 stock top end?

30-40 unported with a pipe (depending on which stock jug) and a properly tuned carb with correct timing.

40-50 porting with a good pipe and 15 carb.

Re: Top speed to expect from a Puch e50 stock top end?

I need to learn to port.

I can get 35 out of a stock low torque 2hp, stock pipe, 14 mm carb, metal mesh filter, 16 x 45 gears.

But I’ve been told 45 is doable with a ported hi torque top end, same pipe, carb and gears. I don’t have a hi torque top end to experiment with, and I don’t know what to do with it if I did anyway.

I need to learn to port.

Re: Top speed to expect from a Puch e50 stock top end?

There was a guy on here recently who reckoned him and his mates were getting 60 out out modded standard parts back in the 60's or 70's!

Re: Top speed to expect from a Puch e50 stock top end?

This is the best porting for a high torque cylinder

Re: Top speed to expect from a Puch e50 stock top end?

How forgiving is porting on these stock top ends? Will a less than perfect job ruin the jug / cylinder?

Re: Top speed to expect from a Puch e50 stock top end?

Good video. Looks easy enough. I’ll need to pick up a new Dremel and bits. Then I’ll need to find a hi torque top end or two to play around with.

Re: Top speed to expect from a Puch e50 stock top end?

its pretty forgiving, but if you use the 1/8 carbide dremel tile cutter bit its very easy, just go slow, take off 1/2 mm at a time and re-install and test it, then repeat, the fastest cylinders i've ported have very little material removed from them. i have a 45+ mph with great torque port map that i've done on a bunch of builds that only raises the exhaust like 1.5 mm, most people go hog wild and port way too much.

Re: Top speed to expect from a Puch e50 stock top end?

Dirty30 Dillon /

I'll nudge towards Graham's statement as well. I have always found that the stock cylinders on Puchs are pretty well designed, given they are the 2hp models.

I typically avoid fucking with transfer shaping at the base side of things, simply because I feel like you want to keep the pumping pressure up. I also worry about fucking with the roof of the transfers and throwing the laminar flow across the piston crown all to hell.

I do like that short video though.

Re: Top speed to expect from a Puch e50 stock top end?

oh yeah i meant to say the aluminum cylinders- in my experience- perform better. they rev a lot higher out of the box, they are easier to port

Re: Top speed to expect from a Puch e50 stock top end?

Angry Hipster /

So the alu series rev higher go faster and can be made to go even faster with porting.

Is the hi torque not capable of this for some reason?

I know the high torque and alu series are made of different metals. And the high torque has a longer piston that increases compression??

Is there different mapping between the two? What exactly are the differences?

Re: Top speed to expect from a Puch e50 stock top end?

the high torque has smaller closed transfers which have better charge motion at low rpm (hence the 'high torque') whereas the aluminum has big open transfers

out of the box the aluminum has a bigger intake port

the HT is also cast iron on the inside, its nice german cast iron not that slovenian tomos shit that is hard as a rock, so it actually ports really nicely with carbide tools but is still way easier to port aluminum.

Re: Top speed to expect from a Puch e50 stock top end?

Probably Fred /

> Graham Motzing Wrote:

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

> oh yeah i meant to say the aluminum cylinders- in my experience- perform

> better. they rev a lot higher out of the box, they are easier to port

Yes aluminum cylinders rev out real good but don’t rule out using a Magnum top end, they make good all around power (magnum X even better) while using a magnum pipe fit on a maxi and just adding one 5/16 hole in down in a magnum pipe and then one hole in the endcap,

open the intake hole on the cylinder a few mm and remove a bit of the skirt that protrudes in TDC, sand head down a bit (all puch heads need to be taken down somewhat)

It’s almost like kitting and piping your bike, and many times you could get them free when people kit their bikes,

A magnum cylinder has big fins has a lot of metal, runs cool at higher timings and magnum pipe has a chamber in it,

I got a magnum II basically unported with those simple mods and stock pipe on it that beats most mild kitted bikes on take off and goes low 40s very reliably and I had a mild ported one on it before that went 45mph but after a few years and being old and used from the start anyway it wore out/ovaled,

Re: Top speed to expect from a Puch e50 stock top end?

> Overpriced Parts Wrote:

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

> > Graham Motzing Wrote:

>

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

>

> > oh yeah i meant to say the aluminum cylinders- in my experience-

> perform

>

> > better. they rev a lot higher out of the box, they are easier to port

>

> Yes aluminum cylinders rev out real good but don’t rule out using a

> Magnum top end, they make good all around power (magnum X even better)

> while using a magnum pipe fit on a maxi and just adding one 5/16 hole in

> down in a magnum pipe and then one hole in the endcap,

>

> open the intake hole on the cylinder a few mm and remove a bit of the

> skirt that protrudes in TDC, sand head down a bit (all puch heads need

> to be taken down somewhat)

>

> It’s almost like kitting and piping your bike, and many times you could

> get them free when people kit their bikes,

>

> A magnum cylinder has big fins has a lot of metal, runs cool at higher

> timings and magnum pipe has a chamber in it,

>

> I got a magnum II basically unported with those simple mods and stock

> pipe on it that beats most mild kitted bikes on take off and goes low

> 40s very reliably and I had a mild ported one on it before that went

> 45mph but after a few years and being old and used from the start anyway

> it wore out/ovaled,

Do Free Spirits come fitted with Magnum top ends and exhaust?

Re: Top speed to expect from a Puch e50 stock top end?

Angry Hipster /

Not that I've seen

Re: Top speed to expect from a Puch e50 stock top end?

Chöschi21 C.K. /

> Graham Motzing Wrote:

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

> its nice german cast iron not

*Austrian

Re: Top speed to expect from a Puch e50 stock top end?

saw that too, not sure how reliable those numbers are

its like those old stories about an old lady buying a base Chevy Nova at a dealership that turns out being a factory tuning car mistakenly sold that contained some experimental carb or tranny or something

Re: Top speed to expect from a Puch e50 stock top end?

Dan (high idle) Conway /

Realistically 35-37 i’ve found after owning a measly 3 e50 bikes Tune your clutch to engage real high! Run 15w-40 diesel motor oil in the trans (Graham’s idea) blue springs 2.5 turns out. with 50cc the clutch is what kills take off.

This setup lets it slip a bit more, while not putting as much pressure on the clutch shoe posts. Just my 2 cents.

Re: Top speed to expect from a Puch e50 stock top end?

200mph

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