Actual hp/torque/rpm for 2003 People 50 2t

[taurus6]

Nice forum, had to join! After a lot of conflicting information, I could use some help please. The service manual for the 2003 People 50 2t says power band is 1.76kw@5400 and .33kg@4600. However, I read somewhere else that it is actually 2.72kw@6500 and .4nm@6000.

Here's what the KymcoUSA tech guy told me. He was reading off a document and said he did not know first hand. Power band is 1.76@5400 and the stock CDI with green wires connected is limited to about 5600 rpm. Disconnecting that wire would employ a new limit of 7500 rpm. It is not "unlimited" but protects the motor at it's limits. He also stated that he could recommend a max. sustained cruising rpm of 6000-6500 with short runs (<=10minutes) at 7000-7500 rpm.

With stock engine,  cdi at 7500 /Naraku cvt with 8g weights, acceleration for me at 190lbs seems very acceptable. Up to a verified 35mph in 8 seconds from stop. Top speed verified is 43 with 48 on speedo. I'm just looking to be able to cruise at "real" 50 and not be the pokey one on local roads where limits are <=50mph. I know a lot of mods will get me up to speed quicker but I'm happy where I am now. Just looking for a little more top end. CVT is running at max ratio based on magic marker wear pattern.

So my questions are the following: What is the actual power band? What is the max. cruising RPM on stock motor for continued periods? Is he being safe with his numbers? Does anyone have real-world knowledge for example that they have been running xxxx rpms for long periods with no issues on stock engine. And lastly would just allowing engine to turn more rpms accomplish this and if not how to actually get there?

Thanks for your help!

[zombie]

The shortest possible answer is... The exhaust pipe determines the power band. A good pipe set to 8000-8500 rpm's will get you 50mph top, and 45 all day cruise. Your pipe stops at 7000 so running above that rpm just makes heat, and no more power. So at 7000 rpm you do 40ish... with a good pipe you can raise the cruise rpm, and the speed.

[taurus6]

Zombie, thanks for the short answer. Based on your other postings you seem very knowledgable. Here is my current plan based on the goal of increasing top end by moving power band of motor up to sustain higher rpms.

Leo Vince Touring exhaust with restriction ring removed if it has one.
Current main jet is #85 so get a 90,92,95 jet. Start with 95 and work down if needed. Do I need to change/adjust the needle as well? More air intake?
Experiment with roller weights around the 5-8gm range, keep clutch parts as-is.

Comments or suggestions are appreciated. Thanks.

[axy]

Your numbers seem to point to air cooled engine.
I had air cooled Kymco with the same engine in 2002 and it is not realistic to expect 50 mph cruising speed, or even top speed with 3.5 hp, regardless of the mods or the pipe, if mods do not include different displacement of the engine.

If I remember correctly, top speed of my scoot was around 47 mph on flat surface.

With 2 stroke 50 cc, usually top speed = cruising speed , so that was the cruising speed too.

To have true 50 mph cruising speed with some extra space above that, you need at least 9 hp 125 cc 4 stroke scoot.

[taurus6]

Hi Axy. Actually I would be ok with cruising a solid 45mph so I was assuming that in order to do that for prolonged periods of cruising time the engine would need the ability to do a little more. This is assuming that you don't want to cruise WOT. Currently at the max. speed of 43mph my rpms are at 7500. If this little engine can run at that speed all day long then I'll save money on upgrades. Zombie's suggestion of moving the power band higher to keep the engine cooler seemed logical in that maybe with the mods the engine can run at 8500 but I would not expect to hold that rpm for cruising. Therefore if i cruise at 45mph/7800rpm? then I have a cooler, safer engine with some safety overhead. If the consensus is that this engine CAN run at 7500 all day long stock, then It will stay as-is. Thanks for you help.

[zombie]

You are both right. but Axy is forgetting you can turn the throttle backwards too. Your roller/jetting/pipe will gain you rpm's/torque. You may be better off, and save some money by using a 1500 contra spring instead of the roller swap. The spring will require more effort from the rollers making them "appear" lighter to the engine. One thing I would do before buying the leo is Verify the power band of the pipe with SEVERAL sources. That is if Leo doesn't not release the info to you. You don't want to end up with a new pipe in the same power band. The Technagas RS2 is an 8500 pipe, but I don't know about application for your bike. You can tune the cvt to run best at 8500, and back off the throttle to keep 45 with NO ISSUES. My ZX was tuned this way for 2 years before I bought it. I just wanted more so I did more.

[wordslinger]

..zombie, bro...you have explained this very well...

..i'm seeing the same thing with my s9...more rpms are not always the most desirable with these 2t scoots, and these oem pipes won't respond to much over 8400, so it seems...

[zombie]

It is really a combo of the port timing, and the pipe. Timing is what really determines the MAX rpm's of the engine. Say it is timed to run max torque at 500 rpm. After that mark you are just adding fuel, and fuel makes heat. All of the two stroke engines I have dealt with are timed higher than the exhaust. The exhaust falls flat at a lower level than the engine to prolong engine life. Bumping up the exhaust will allow the engine to reach its peak where ever that final mark is. You can hear when it stops pulling, and throttle does no more good. Perfect tuning is when the pipe, and exhaust are on the SAME rpm band. That is what I am trying to get on the ZX right now.
One small experiment you can try is to WRAP the pipe back to the end of the header to increase the temp of the pipe. This will raise the power band because heat allows gases to travel faster. This alone may get 2 4 mph out of an under range pipe. When I figure the timings on my new set up wrapping is in the index.

[wordslinger]

..school is in for me bro, what you say'in answers many questions i had...

..explains what i've been seeing...

..btw, my s9 jumps off the line @7900...and accelerates it's best @ 8100...hits 60 indicated @ 8400...


..really flat rpm band there, but if i venture any lower, or much higher, i seem to lose torque....

[zombie]

With out changing Anything on the engine you can up the gears to increase the top end. That is where Axy's post comes in... You will run out of torque before any infinite gears. Malossi has the Primary set that is just 10% up. but would get you 6 mph at the same rpm's. With that you can twist back, and cruise at your old wot. To compensate for the taller gear either a stiffer contra or 1/2gr lighter rollers will keep your et the same.
Of course I'll hook a brutha up on the gears but mine took six weeks from Italy. There is that Red elft? guy that posted a few things here that has them in hand, at just a few bucks more. I think it was like 50 -60 bucks. If you can't find his posts... I'll order a set. I have 4-5 items to order next week so let me know.

[wordslinger]

..actually, on my 50 s9, i'm content with what i have now...


..she never falls below 45 indicated, and 60 @ 8400 is just fine with me!!!

..she's my everyday, 40 miles a day workhorse...


        ..and she's queen of the mountain around here....




                                   

[zombie]

Awwww!

[wordslinger]

..i'm running a 1500 contra now...and i have rollers and sliders in dang near every applicable wt...lol..

..i do, however have a MHR red contra, still in th plastic...

[zombie]

Trust me... you don't want to use the red unless you are over 15hp.
it is too much stress on the cvt. I'm eating cvt parts for lunch. Going to try a 1500 with this build... So I can go back to lighter rollers. I was running 9gr w/ the red.






just too much stress

[Areomyst]

My People 50 has 4.14 HP at 7850 RPM, and 2.76 ft lbs of torque (SAE Correction factor).  I have not yet been able to do dyno testing without the CVT in play (I'm slowly working on that) but the bike runs really well, and maintains speed like a champ.  I have extensive CVT mods done, which I don't want to post yet because I'm still "beta testing" the reliability of my setup (belt life, component wear, etc). I'm using a hodge podge of mixed-up inexpensive aftermarket parts that have not been adequately tested otherwise I'd just post up the whole setup, but I don't want someone to copy the setup and the end up stranded with a broken belt or whatever, so I'll wait untill I get a couple thousand kilometers on it before posting. 

 I have a Leo Vince GP exhaust, Dr. Pulley sliders (currently 7.5 gram, but I'm always tweaking it).  For the record, I've got a little more work to do with the torque driver and different weights still.

On flats and small inclines, it maintains speeds above an indicated 50.  I have not GPS tested, so I don't know quite what accurate speeds would be.

I have a new clutch that I'll be installing soon, as I'm currently using the stock clutch with harder springs and it's still leaving much to be desired.  Clutch needs to engage much later.  Heh.

Cheers!

~Josh