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Post by 50dude on Nov 20, 2011 17:58:54 GMT -5
Is it achievable?
I do not really want to install a big bore kit, and I'm wondering whether or not I could hit 50mph with maybe an up jetted carb, new exhaust with bigger tubing, cylinder head work etc..
Any thoughts?
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Post by mainepeace on Nov 20, 2011 18:13:20 GMT -5
Possible, but you would need a lot of custom parts.
The BIGGEST way to more power is through airflow. This is what creates the power. A larger displacement will flow more air, period. That is the simple way to do it. A better flowing small cylinder engine will flow more air and will produce more power too. Of course you are limited by simple things like compression ratio and combustion efficiency.
The second way is to reduce parasitic drag.
The third way is to optimize the power transfer from the crankshaft to the rear tire.
It's possible if you have everything else setup properly.
Greg
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Post by 50dude on Nov 21, 2011 12:21:55 GMT -5
So do you think I should have the head modified for a better compression ratio? As for weight, the bike is an extremely light small frame, I have stripped several parts to save weight. Im just about to go and weigh the bits I have taken off, and will post the result on here. I weigh about 140.
I was thinking of fabricating a new from section for the exhaust, apparently the standard tubing is quite restrictive.
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Post by inuyasha on Nov 21, 2011 12:33:42 GMT -5
Hi
I weigh around 170 and my Puma Hits 50+ GPS certified
Milled the head and different thickness gaskets gives me around an 11 to 1 compression ratio
Besides that all is stock
You should have no problem achieving the same speeds witha little bit of work and some small upgrades
Your light build is the biggest saving, the lighter the rider the faster the scoot
Take care and drive safely
Yours Hank
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Post by 50dude on Nov 21, 2011 13:04:07 GMT -5
Thanks very much for the vids  How much did you take off the head? |
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Post by inuyasha on Nov 21, 2011 13:23:39 GMT -5
Thanks very much for the vids How much did you take off the head? Hi Your most welcome ;D I went .020" over Take care and drive safely Yours Hank |
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Post by tortoise on Nov 21, 2011 13:51:53 GMT -5
weigh around 170 and my Puma Hits 50+ GPS certified . . Milled the head and different thickness gaskets gives me around an 11 to 1 compression ratio Besides that all is stock Did you happen to measure the cylinder diameter when the head was off for milling? Very hard to believe 50mph on level terrain (with no tailwind) from an actual 50cc 139QMB! |
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Post by 50dude on Nov 21, 2011 13:53:47 GMT -5
Thanks for the info, I will get the machine shop to take off the same amount I was thinking of moving the flywheel pickup anti clockwise a few mm, we do it on 125 motorbikes round here and it works well. It just gives the extra ignition advance that those cdi's always pretend to have ;D |
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Post by inuyasha on Nov 21, 2011 14:14:44 GMT -5
weigh around 170 and my Puma Hits 50+ GPS certified . . Milled the head and different thickness gaskets gives me around an 11 to 1 compression ratio Besides that all is stock Did you happen to measure the cylinder diameter when the head was off for milling? Very hard to believe 50mph on level terrain (with no tailwind) from an actual 50cc 139QMB! Hi Yes indeed i did 39mm so shes a 50cc actually 49.6 cc to be exact And gps certified ive had her up to 52 mph with a little more to go Pumas which are made by Zhen imho build quite a marvelous scoot www.pumacycles.com/Btw i use the highest octane fuel i can get 93 to 94 Take care and drive safely Yours Hank |
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Post by tortoise on Nov 21, 2011 14:48:20 GMT -5
gps certified ive had her up to 52 mph with a little more to go For comparison . . the E-TON Sport 50 specs are 49.4cc 4-stroke with an 11.8:1 compression ratio and 12" wheels. This owner states "I can get about 40 on flats". |
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Post by 50dude on Nov 21, 2011 15:34:50 GMT -5
The bikes with 12's are quite abit heavier, and we don't know how heavy the rider was.
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Post by inuyasha on Nov 21, 2011 16:13:02 GMT -5
The bikes with 12's are quite abit heavier, and we don't know how heavy the rider was. Hi I agree My Puma Angel weighs 188 lbs net i weigh around 165 to 170 lbs Not here to argue with any one But i know what shes capable of and its not just a boast 50+ mph GPS certified Take care and drive safely Yours Hank |
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Post by 50dude on Nov 21, 2011 16:26:07 GMT -5
Well either way I will be modding my scoot whilst keeping the 50cc barrel.
Plans are;
Stock muffler we the end baffle removed, and a larger downpipe/header
88 jet
Head skim
Port work
High octane fuel
What do you think?
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Post by inuyasha on Nov 21, 2011 16:26:19 GMT -5
gps certified ive had her up to 52 mph with a little more to go For comparison . . the E-TON Sport 50 specs are 49.4cc 4-stroke with an 11.8:1 compression ratio and 12" wheels. This owner states "I can get about 40 on flats". Hi Your mistaken on the compression ratio Compression is only 6.8 to 1 not 11.8 to 1 its listed in the full specs www.etonamerica.com/PDF/SS/SS_09_PN2D.pdfMy engine is slightly over 11 to 1 And does achieve the speeds i stated I can go 35 to 40 and maintain it quite easily up a slight uphill grade And with any of my daughters on the back as a passenger still get to the high 30s almost 40 Take care and drive safely Yours Hank |
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Post by inuyasha on Nov 21, 2011 16:33:12 GMT -5
Well either way I will be modding my scoot whilst keeping the 50cc barrel. Plans are; Stock muffler we the end baffle removed, and a larger downpipe/header 88 jet Head skim Port work High octane fuel What do you think? Hi Sounds like a good plan for a start Take care and drive safely Yours Hank |
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Post by 50dude on Nov 21, 2011 17:03:58 GMT -5
I might even go a little bigger on the head skim, maybe 1mm, what do you think?
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Post by inuyasha on Nov 21, 2011 17:13:46 GMT -5
I might even go a little bigger on the head skim, maybe 1mm, what do you think? Hi Anywhere's between .010 and .030 are the accepted ranges for a fairly reliable mostly stock engine any more and you risk damage to the stock components Any thing over that range and you should use performance related parts in the engine Take care and drive safely Yours Hank |
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Post by charlesg1975 on Nov 21, 2011 20:47:47 GMT -5
For one thing there is no such thing as GPS certified. The only way to get an accurate reading is a radar or laser device. I got a ticket in Georgia three months ago, my speedometer on my 1500 Chevy truck said 75, the GPS said 82 and the Georgia state troopers laser said 76. I paid the ticket and believe what the gun said over a GPS that has to send its signal from the ground to space and back to my GPS.
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Post by edfr on Nov 21, 2011 21:28:55 GMT -5
Look at all the 50ccs SPEC DETAILs and they all say 35+ depending on rider and conditions. Which is what you can expect from a 50cc motor and some only low 30s to boot. And may I add dealers will usually change the specs UP not DOWN to get more bites. www.pumacycles.com/To get a 50 to break 40mph is even a tough task. CHARLESG1975 Right on Bro, GPS is an ESTIMATE from one point to another and a lot of things can disrupt the signal a telephone pole trees buildings, storms blocking the signal from the orbiting satelites etc.. So it takes the first point and then estimates the end point. I don't understand why so many claim unbelieveable mph on a 50 that even on some 150s cannot be obtained unless modded. Some even claim higher mph that is obtainable by the 250s. Just remember Displacement gets you more power and torque and more power and torque MAY get you more speed if other items are also changed. Unless it is a raceing engine which has been built by professionals and gets built just about every run be ver leary of claimed MPH. Lefty |
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Post by mike6736 on Nov 21, 2011 23:12:26 GMT -5
A stock 50cc doing 50 mph?
I'll have what he i drinking.......
Mike
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Post by inuyasha on Nov 22, 2011 8:20:38 GMT -5
Hi Not a stock 50 read my posts My speedo is wrong gps is wrong  Some of the members here are really something To the naysayers and those that scoff at my statements If you have seen any of my videos and they are posted for all to see IM on roads that range from 25 to 45 posted speed limit I more then hold my own and can easily keep up with the traffic and at times exceed them So believe it or not I KNOW WHAT MY SCOOT IS CAPABLE OF Take care Yours Hank |
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Post by edfr on Nov 22, 2011 8:49:26 GMT -5
Set one up for me mike, I don't know what the drink is but I will try it  . Lefty |
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Post by mike6736 on Nov 22, 2011 9:50:49 GMT -5
I don't know...I am to old anyways to have a rocket in my pocket.....I was aty a stationthe otherday and this guy cam over to my Honda and said wow, I was was doing 65mph and you flew past me how big is that thing. I was riding my Honda Reflex which is a 250cc and I was also only traveling at 60mph. That is with my speedo saying 64mph and my mounted GMS saying 60mph. This young man was riding a Chino 150cc and said no way my speed is right oin the money. I think someone in the line of traffic behind him would have told him the same thing.
As for Lefty...The bar is CLOSED...we have no rabbit juice here, try the water hole they visit
Mike
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Post by buford1488 on Nov 22, 2011 13:33:52 GMT -5
don't say it if you can't back it up!!!!!
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Post by mainepeace on Nov 22, 2011 14:01:54 GMT -5
The truth is that NOBODY will be able to verify or validate another's claims of speed or power unless they get together and actually race each other on the same street (not that I condone street racing). There are always going to be issues like weight, rider weight, windspeed, terrain, traffic, etc. that will skew results from one to another. Add to that one rider's personal experience (which may be good or BAD) and you will always get different conclusions from the same data.
For me I don't trust GPS for many reasons. It's not the technology. The basic technology is great and can be accurate to within 3 inches with the proper error control and security protocols. A handheld purpose built GPS is good and solid, but it was designed to be used in a VARIETY of locations and mainly for LOCATION and not SPEED. The speedo is probably an afterthought and not meant to be super accurate (and can't be due to security issues).
A GPS app on a phone is even more suspect, as the programmer could have been any teenager or college student at home just using basic software hooks to activate the built in GPS receiver and doesn't really know how to program a fail-safe software package. I've downloaded and tested 30 different GPS for Android apps and they are all different, even when I'm sitting at my desk with 180 degrees of windows around me. When one shows I'm going 180 mph while sitting at my desk, I severely suspect the coding behind it. They even show different latitude and longitude, which they shouldn't if they were accurate to 12 feet.
When you take this and realize that speed calculation is just taking two different locations and measuring the time it takes from one point to another, you can see how if a measurement is even .001s off or 10 feet off it can make a significant difference in the displayed speed. A few trees and buildings can (and do) reflect GPS signals and affect the accuracy.
At least 3 satellites are supposed to be in view at any one time on any point on the world. I'm supposed to be able to view 7 from where I am, at sea level and a perfectly clear sky with no mountains nearby. I'm lucky if I get signals for two.
Average speed is another thing, but most people don't ride straight and level for 2-3 miles it would take to get an accurate average speed rating from an inaccurate GPS app, except in Texas or New Mexico.
Greg
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Post by lbo on Nov 22, 2011 15:16:02 GMT -5
Before I put a BBK in my 50cc 2T I hit 47MPH on flat land (it's all flat around here) and a slight tail wind. Only mods were a tuned pipe (gave biggest increase), racing variator, sliders, and well that's it really that would affect top end. Speed was calculated from a GPS phone app and the indicated speed on speedo was ~55mph (speedo goes to 50). I was playing with jetting and running really lean at the time. Typically I could hit about 45mph with relative ease with no wind and I weigh about 220lbs.
Just throwing it out there and understand it might not be 100% accurate. The LC version on my scoot claims to reach 50+ consistently when de-restricted.
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Post by marvintm on Nov 22, 2011 20:07:20 GMT -5
well i know i have mine doing 50-60kph easily now with the air intake and performance muffler and my spedo has been checked but a car chasing me and gps.
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Post by edfr on Nov 22, 2011 20:20:30 GMT -5
Marvintm,
Good for you that is decent and may I say honest for a 50cc . The difference is that others are claiming the 50-60 numbers in US MPH your claiming them in 50-60KP/H huge difference between KP/H and MPH.
Lefty
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Post by inuyasha on Nov 22, 2011 21:06:15 GMT -5
Hi
Never once did i say she could attain 60mph or that my scoot could out race a 150 or larger scoot
Those are your words and where you got that from i cant imagine
But she can go slightly over 50 MPH which i may add is physically possible
And its the reason that my Indian is a long distance cruiser now
The scoot is more then capable of keeping up with any of the backroads, secondary or main roads where i live some that have 45 mph speed limits
The only one she can not keep up with are the interstate and the highway speeds
Im quite happy with her performance and thats all that matters what you may or may not believe matters not in the long run
I see now that some will never accept some ones word even when they have video evidence to back it up and just be happy for them and how well their scoot performs on the road
So i will drop the subject
Take care and drive safely
Yours Hank
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Post by edfr on Nov 22, 2011 22:44:51 GMT -5
You have to admit all the 50 pumas the specs say 35 mph depending on rider conditions and whatnot. So when you say you JUST MILLED the head and are getting 50+ mph I have to disagree with those claims. Milling the head WILL NOT give you 15mph gains all that does is give you low end torque and if you ever noticed your rpms will NOT rise as high as with the OEM head.
And NO I did not say you could out race a 150 or do 60 but remember this a 150 scoot out of the crate will usually do 50+ now that is 100 more ccs approx 5-6 more hp over a 50cc.
So your claim of 50+ is very hard to swallow as they say.
Also I did not see any Video Evidence of the speedo or gps on the scoot. If you are talking about the two Videos in this thread all the Video Showed was the side of the road you where traveling. I did not see any SPEEDO shots or even the scooter for that matter.
All I am trying to say is MOST of us know what SPEEDS you can expect out of a 50, 150 and 250 stock. And we also know what Mods will get you some top end speed and about how much. Just think about it a 50cc EVEN with a BBK and all the goodies you will be in the 40+ range but not 50. Very few and a lot of money thrown at it ever break or reach 50 and then the motor does not last very long.
I get concerned when someone comes on with high mph claims because the younger crowd will go out do what someone said got him 100mph and his only goes 38mph with the same mods.
Lefty
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