4 or 6 port cylinder better for torque? (50cc)

Hi,

Bought a late model 1hp Puch Maxi kickstarter with a fresh rebuild and planning to upgrade the top end. Will upgrade intake and exhaust accordingly.

Due legistlation I am leaning towards 50cc kits. And due heavy penalties I cannot exceed 40mph, so top speed target somewhere below that. Hoping to get good acceleration and torque to climb hills though. And I want to keep it under 10K revs at all time.

I see DMP and Power One offer 6 port cylinders and basically everybody has 4 port ones.

So, would you recommend 4 or 6 port cylinder for hill country and town driving?

Thanks.

Re: 4 or 6 port cylinder better for torque? (50cc)

At first I I thought hummm these laws are stupid. Then I thought this would be a fun challenge.

I would do the DMP and a Circuit pipe unless you have noise restrictions....which I think could be a fun work around too.

What ever speed you end up at I would just play with the gearing to get it right at 35-40.

I say DMP, circuit pipe and 15bing. Should

Be a fun bike.

Re: 4 or 6 port cylinder better for torque? (50cc)

Yeah, laws are what they are. Here max legal speed for moped-class is 40kph (25mph). If I exceed 45kph (28mph) I will get a 20-200€ fine depending on the situation. If I get caught driving 50-65kph (32-40mph) I'll get a bigger fine according to my net income. And if I am clocked going faster than 40mph they will take my plates, issue me max fine according to my income, my bike is classified as motorcycle and I am fined for driving a motorcycle without an insurance and then I must pay 3 years of motorcycle insurance (for nothing) and return my bike to moped-class vehicle (stock motor), get it officially inspected and reregistered. So, the 40mph+ offence could cost me something between 1000-2000€ ($1200-2400) and several days of work. So, that is what I am trying to avoid. ;-) Well, luckily at least they don't confiscate and destroy tuned bikes like they do in some countries.

But, yeah - if miracle would happen and bike would end up too fast its not too difficult to slow it down.

There is no noise restrictions but cops might inspect and test drive a moped which sounds too much like kitted one. Also pipes that are clearly out of place on vintage moped can arouse interest. So i better stick with vintage looking chrome pipes which are more open but not too noisy or "racy" looking.

Coincidentally, look what the postman just brought me 5min ago: (edited)

Bing 15mm 3.jpg

Re: 4 or 6 port cylinder better for torque? (50cc)

The cops test drive your moped? Damn, I'd love to see that. The cops around here would either crash mine, or try to get all Moto GP on it.

Re: 4 or 6 port cylinder better for torque? (50cc)

Tony. You dont have to replace the top end at all unless it is too beat up to use still. Your max speed of 28mph is the stock max speeds of that cylinder you have. But for better hills the 6 port will most likely give you the most bang for your buck but you will want to back it up with a better pipe than a stock one, which is heavily restricted and not good for low end, which you want for hills.

While I understand you concern about the pipe alteration getting you noticed, you can really restrict the speed of the bike with gearing which will only add to your low end power anyway. You could gear it to max out at 28, and have the engine screaming at like 9k RPM. It would be fun sounding and loud, but it wouldnt get you into any trouble and fined.

Re: 4 or 6 port cylinder better for torque? (50cc)

I don't know if it's an option but this guy would bolt on and be totally ripper with a stock style pipe:

https://www.treatland.tv/tomos-A35-38mm-50cc-airsal-kit-p/tomos-airsal-kit-02210138.htm

You would probably have to fab up your own intake

Re: 4 or 6 port cylinder better for torque? (50cc)

> baird co Wrote:

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

> The cops test drive your moped? Damn, I'd love to see that. The cops

> around here would either crash mine, or try to get all Moto GP on it.

Yes, its not that rare for cops to test drive and speed test mopeds for illegal mods (all motor mods are illegal) but they mostly harass kids. Many such videos in youtube. So, basically I am quite safe as long as they don't catch me speeding.

Cop College is 3-4 years or something so they are quite pro in what they do. And most have driven (and even tuned) mopeds as kids themselves. (edited)

Re: 4 or 6 port cylinder better for torque? (50cc)

> Jay Rivett Wrote:

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

> Tony. You dont have to replace the top end at all unless it is too beat

> up to use still. Your max speed of 28mph is the stock max speeds of

> that cylinder you have. But for better hills the 6 port will most

> likely give you the most bang for your buck but you will want to back it

> up with a better pipe than a stock one, which is heavily restricted and

> not good for low end, which you want for hills.

>

> While I understand you concern about the pipe alteration getting you

> noticed, you can really restrict the speed of the bike with gearing

> which will only add to your low end power anyway. You could gear it to

> max out at 28, and have the engine screaming at like 9k RPM. It would

> be fun sounding and loud, but it wouldnt get you into any trouble and

> fined.

The kits are quite cheap and hopefully give a nice boost so I don't mind getting one. Just unsure if 4 or 6 port is better for me.

The Maxi came with no name aftermarket pipe with an expansion chamber but it still has the stockish 22mm header (18mm inside?). Don't know yet what the actual performance of this one is as there is too much snow but I will test drive it and see asap. I think that in stock condition it should go like 15mph or something. ;-)

But, tinkering is fun so in any case I will do some updates.

Re: 4 or 6 port cylinder better for torque? (50cc)

> Graham Motzing Wrote:

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

> I don't know if it's an option but this guy would bolt on and be totally

> ripper with a stock style pipe:

>

> https://www.treatland.tv/tomos-A35-38mm-50cc-airsal-kit-p/tomos-airsal-kit-02210138.htm

>

> You would probably have to fab up your own intake

Thanks for the suggestion but Reeds are no go here. They spot them immediately as old mopeds didn't come with them in my market. Or at least I don't know any that did.

One good thing is that Maxis were never imported here so they are mega rare. Cops will not know what it actually had. And in registration inspection they didn't write front and rear sprockets or the carb size to the registration papers so I am quite free to choose my own.

Re: 4 or 6 port cylinder better for torque? (50cc)

Very cool thanks for sharing!

You can click 'flat view' to view the forum the way most of us do, nobody can see what threads you are replying to, so it gets confusing.

The 6 port kit that I've used is the tccd, I'm not sure how that compares to the dmp but in my opinion they are over ported. I much prefer a stock aluminum cylinder with porting. You would just gear down to 14*45, but then you end up riding around at high rpm which can be unpleasant.

Re: 4 or 6 port cylinder better for torque? (50cc)

> Graham Motzing Wrote:

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

> You can click 'flat view' to view the forum the way most of us do,

> nobody can see what threads you are replying to, so it gets confusing.

I am in flat view (always) and I did click quote for each reply. I see everybodys quoted text before my replies. Don't you see them?

Re: 4 or 6 port cylinder better for torque? (50cc)

> Graham Motzing Wrote:

> The 6 port kit that I've used is the tccd, I'm not sure how that

> compares to the dmp but in my opinion they are over ported. I much

> prefer a stock aluminum cylinder with porting. You would just gear down

> to 14*45, but then you end up riding around at high rpm which can be

> unpleasant.

I pretty much would like a plug and play kit. So no porting work for this project but I can do chamfering etc. small clean ups which are required before installation.

This Maxi will also be ridden by my wife also so it must be nicely behaving. You know, almost feel like stock but more power/tq. ;-)

Re: 4 or 6 port cylinder better for torque? (50cc)

Tccd = dmp

Same same.

Re: 4 or 6 port cylinder better for torque? (50cc)

> Jay Rivett Wrote:

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

> Tccd = dmp

Power One also looks very much like DMP in pictures but one of the European resellers for both told me that in his opinion Power One is better quality.

Re: 4 or 6 port cylinder better for torque? (50cc)

Just checked and my sprockets are 13x45 (0.288 gear ratio), which I believe is stock for late model 1.0hp model. I have ordered a 14 tooth replacement but maybe I should get a 15 too for testing?

Any more input on which is better cylinder-type for low/mid torque? I am sure somebody still does 50cc kits and has tried the 6-port versions, please tell me how they work comparing to traditonal 4-ports?!

I'll give two clear examples so it might be easier for you guys:

- DMP 6-port 50cc

- Airsal 4-port 50cc (edited)

Re: 4 or 6 port cylinder better for torque? (50cc)

Yes and I have said that the 6 port is better. It is better at scavenging fuel due to the extra boost ports, so it to me is a more powerful kit.

However the more you add speed into your gearing the slower your bottom end will be again. With either of the kits you are going to need some clutch tuning done to get some better takeoff and help the bike stay in the powerband longer and easier.

The 14t sprocket will end up giving you more top speed oveall, it will just take longer to get there. Anything bigger than that you will need to buy a new chain and a motorcycle chain breaker to get it to the correct length.

If I was in your boat and worried about fines, which I'm not. My state can lay out some stiff penalties as well. I would grab the 6 port cyl, (tccd/dmp/power1) probably the power 1 since it is available closer to you. I would also get some stiffer springs for your clutch. Probably the blue ones in a stock-ish setup.

I would look at doing a little port work for low end gains, lots of reading to be done on that in the wiki on here.

I would also get a low range pipe. Circuit or sidebleed pipes are good for this.

I would leave the gearing alone as it will limit my top speed. With the gearing and the pipe you are going to hit a hard wall of top speed that you cant go past. Like you will be screaming at 9k RPM but only doing 30mph.

Make sure to get a range of jets as you need to go up a bit with the new kit and a new pipe. Plus a good hi-flow foam air filter will help on your carb. Do NOT get the metal mesh hi flow filter for the bing. It is garbage.

Re: 4 or 6 port cylinder better for torque? (50cc)

I've run the tccd kit and I think it's over-ported, the exhaust and intake are too big. I don't know how it would run with a stock pipe but my guess is you will have a hole in the power right where you want to have your clutch locking up at like 4k rpm. They are also kinda bitchy to tune for the same reason.

I think airsal in general does a better job making low-end cylinders, but I haven't run that one. My guess is that it would be better for what you want.

You should probably go looking on some German sites, I know they also have to deal with the 'stock' legality issue and they are clever about getting around it.

America has basically no laws and we are almost all piped or kitted. Heck the road I live on is 45 mph and cars do 60, if my bikes can't do a solid 45, I can't even go buy beer without getting run over.

Re: 4 or 6 port cylinder better for torque? (50cc)

Thanks guys, very helpful. Seems like I just need to take a leap and choose one or the other. BTW. DMP also makes 4-port version with a piston with a hole on the side. Maybe a compromise worth considering?

Didn't say but this isn't my first Puch - its my first Maxi and first E50. My other Puch motors are 2, 3 and 4 speed manuals. I think I have 5-6 of them. And I have been reading Moped Army for 2+ years and other forums too. So, didn't start yesterday but by no means am I a specialist in kitting or tuning. I need to study on how to port for torque but if I remember correctly I should only widen the intake and exhaust ports and not rise them at all? Unless the Power One cylinder ports are too big to start with like Grahams TCCD-kit?

For the Maxi among other things I did order a new chain and new 14+45 sprockets so no problem there. And I do have the tools. So, I can experiment with the sprockets to find ideal pair.

And I do have a genuine Bing 15, manifold and large suite of bing jets, few atomizers and couple of different slides too. In fact I do have 3 genuine Bings and 2-3 replicas.

I think I also have 3-4 mufflers i can try with a Maxi header. I did order a RS Cigar just to try it out as it was cheap and comes with the suitable header.

For ignition I will install the VEC TV-2E one which I bought for my other bike couple of years ago but never used.

I think I will have fun spring trying to figure out a good combo! :)

And the Maxi itself:

Puch Maxi K2-2b.jpg

Re: 4 or 6 port cylinder better for torque? (50cc)

I would listen to Graham for is sage words for sure. I have not played with the 50cc kits from any of the brands but have had all 3 70cc kits. I have just found arisal to be cheap, with not very well lined nikasil sleeves. Honestly if price is not a big concern. Doesnt polini make a 50cc? Or Metra? Those would be torquey for sure.

Re: 4 or 6 port cylinder better for torque? (50cc)

> Jay Rivett Wrote:

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

> I would listen to Graham for is sage words for sure. I have not played

> with the 50cc kits from any of the brands but have had all 3 70cc kits.

> I have just found arisal to be cheap, with not very well lined nikasil

> sleeves. Honestly if price is not a big concern. Doesnt polini make a

> 50cc? Or Metra? Those would be torquey for sure.

Well, they are all within about 20-30 euros of each other so its pretty much the same for me. Its not like I will be buying them all the time....I hope ;-)

Only Polini I found from european shops now is a 65cc reed cylinder kit. And for Metra, only 65cc piston port. But doesn't Metra have angled exhaust flange so some hacking needed to get a normal pipe to fit?

Forgot to comment on the clutch issue: I have a set of blue springs for it in the mail.

Re: 4 or 6 port cylinder better for torque? (50cc)

Overpriced Parts /

> Jay Rivett Wrote:

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

> Tccd = dmp

>

> Same same.

Nope, different In many ways, look at the transfers design

7915AFA5-A83C-4512-8C76-6B15C1AC03EB.jpeg

Porting and base spacing is different also

DMP makes more torque down low, better quality nikail lining too

Re: 4 or 6 port cylinder better for torque? (50cc)

> Overpriced Parts Wrote:

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

> > Jay Rivett Wrote:

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

> > Tccd = dmp

> > Same same.

>

> Nope, different In many ways, look at the transfers design

> Porting and base spacing is different also

> DMP makes more torque down low, better quality nikail lining too

Thank you for your input. Are you now talking about the 6-port cylinders?

Re: 4 or 6 port cylinder better for torque? (50cc)

Overpriced Parts /

> Jay Rivett Wrote:

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

> I would listen to Graham for is sage words for sure. I have not played

> with the 50cc kits from any of the brands but have had all 3 70cc kits.

> I have just found arisal to be cheap, with not very well lined nikasil

> sleeves. Honestly if price is not a big concern. Doesnt polini make a

> 50cc? Or Metra? Those would be torquey for sure.

All three 70cc kits ?

There are several 70cc Piston port kits that come to mind not just 3, Athena, Parmakit, Kstar, DMP, Airsal old and new style fin, power one, 2fast moto, others too,

Re: 4 or 6 port cylinder better for torque? (50cc)

Speaking of cylinders, anyone know more about eso bbk? Akoa have the same. Like old iron metra but in nicasil?

Re: 4 or 6 port cylinder better for torque? (50cc)

Yeah I don't know if the dmp 38mm is the same as tccd.

I have a tccd 38 on the shelf, I could port map it for you. I also have a really good stock cylinder that was low 40s with great torque... I've been meaning to map that one too.

I'm putting a reed intake on that tccd to try to make it more rideable. This is the first proto but I've refined the design a bit since then, will porting the intake, shooting for the 50/50

IMG_20200827_112803.jpg

Re: 4 or 6 port cylinder better for torque? (50cc)

> Overpriced Parts Wrote:

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

> > Jay Rivett Wrote:

>

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

>

> > I would listen to Graham for is sage words for sure. I have not

> played

>

> > with the 50cc kits from any of the brands but have had all 3 70cc

> kits.

>

> > I have just found arisal to be cheap, with not very well lined nikasil

>

> > sleeves. Honestly if price is not a big concern. Doesnt polini make

> a

>

> > 50cc? Or Metra? Those would be torquey for sure.

>

> All three 70cc kits ?

>

> There are several 70cc Piston port kits that come to mind not just 3,

> Athena, Parmakit, Kstar, DMP, Airsal old and new style fin, power one,

> 2fast moto, others too,

Man Roff, I know there are tons of kits. The three that have been most discussed in this thread was the TCCD, DMP, and Arisal. Of which I have had all three.(70cc kits not the 50cc kits the OP is asking about) And so if I take into account everyones thoughts on these 3 cylinders I would say it goes. Arisal < TCCD < DMP

Graham, that reed adapter is dope. I hope you make these available once you get it all worked out!

Re: 4 or 6 port cylinder better for torque? (50cc)

Question:

In your country could you register a moped as a motorcycle? Just costs more then you can have motor mods like reeds and a pipe?

Re: 4 or 6 port cylinder better for torque? (50cc)

> JBOT Admin Wrote:

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

> Question:

>

> In your country could you register a moped as a motorcycle? Just costs

> more then you can have motor mods like reeds and a pipe?

The mopeds have been type approved by the manufacturers as mopeds which have structural max speed of 45kph. I don't know if its possible to change that. Its probably easier to build a motorcycle from scratch and get that registered.

Re: 4 or 6 port cylinder better for torque? (50cc)

Re: 4 or 6 port cylinder better for torque? (50cc)

> Jay Rivett Wrote:

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

> Oh and here is the Metra 50cc...

Thanks. But argh...

1. the price, IMO there is no reason to pay 4-6x what other cylinders cost

2. sounds like high rev screamer to me

3. angled exhaust port, I rather get one that doesn't require cutting and welding

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