what bike meets these requirements?

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mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
I broke the metal handle on the lever wich was just really light cheap pot metal so hopefully the replacement I saw at kings will be better quality. Im not giving up on it but after just a few minutes test driving it i am hooked and need MORE POWER, it has a really funky exhaust on it that goes around the left side of the front tube then curves back and up around the right side then screws into a small expansion chamber then back into a tube then a coke can sized muffler and im guessing it is hurting my power and hopefully ill have the cash to replace it with a better exhaust soon. When you say dual pull does that mean it will operate the front and rear brake at the same time? If so can I set a bias to work the rear a little before the front? Im sorry for my ignorance but I know almost nothing about bikes and have not ridden since I was a kid.
The free-er flowing the exhaust is the better on these engines, and it is possible that the carb was never re- jetted for a better tune which is also very important for power and top speed, that pipe is very restrictive and if you can handle some extra noise put a high flow pipe on it and you'll notice a big power difference.
 

needtransportation

New Member
Mar 17, 2014
43
0
0
Knoxville
I know that on a car if you run with no exhaust you will burn the exhaust valves but since this has no valves would no exhaust make the most power at the expense of being loud or would that hurt the low end torque too much? How do I know if the carb needs rejetted and if I need to go up or down a size? It is a nt carb and Instead of the type of air cleaners ive seen online it has a round plastic piece that has four tubes facing down and looks like the punisher skull.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
I run straight through exhaust on two of my bikes and yes it is louder but as long as the carb is tuned for the extra air flow it wont hurt a thing.

If while under throttle at cruise speed it does what is called 4 stroking In stead of a smooth buzz like what a weed wacker doea when its revved up that means its running a little rich, doing what is called a plug chop or as I call it check spark plug color you can determine when your tune is right, its better to be a little on the rich side than to run an engine lean, these engine will 4 stroke. Some making that blubbering sound at low rpm with no load or little on them but then under throttle they should clean up in sound to a nice 2 stroke brayyyyyyyyyyyyy sound, I dont change jets in my NT carbs I just solder them up and redrill them with a #72 or #73 wire gauge drill bit the bits can be got at widgetsupply.com and a set is about $5
This is the most inexpensive way to change jet size and all it takes is a dab of solder and a small propane torch to heat the jet enough so that the solder will melt to it and fill the hole and it only takes a very small piece of solder to do it.

Hope this helps some and you get it running great soon.
 

Greg58

Well-Known Member
May 1, 2011
5,353
2,575
113
65
Newnan,Georgia
Yes you can adjust the brakes to have more on either wheel, the dual lever from sbp looks to be of good quality. You need to run an exhaust of some kind, 2 cycle piston port engines need some back pressure to run correctly. The trick is getting a free flowing pipe that you are OK with the sound then jetting the carb to the pipe. We all went through this process to get ours to run like we want. We go by spark plug color, you want the white center porsion to be light to medium brown in color. Search plug chop in the search box at the top of this page for a lot of info.
 
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needtransportation

New Member
Mar 17, 2014
43
0
0
Knoxville
The plug is oily and black so I moved the clip on the small brass rod from the third to the top notch and then it wouldnt run at idle so I screwed the screw on the side in a half turn at a time until it would idle nice and smooth and it is almost all the way in but it runs much better than it was last night but it still doesnt have the power I think it should but I think replacing the plug should help alot since its pretty fouled. I also found out that my front wheel isnt quite true so it looks like ill be saving up for a wheelmaster wheel with sturmy archer drum and dynamo to kill 3 birds with 110 stones unless somebody knows of a decent wheel and brake package for a more reasonable price, again sorry for my ignorance but other than thicker spokes being better I dont know what makes one wheel better than another.


On a side note my dumb butt used my brake lever as a clutch lever for testing purposes so I was riding this morning at wot with no brake, must have taken a quarter inch off the sole of my boots to slow down.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Yes you can adjust the brakes to have more on either wheel, the dual lever from sbp looks to be of good quality. You need to run an exhaust of some kind, 2 cycle piston port engines need some back pressure to run correctly. The trick is getting a free flowing pipe that you are OK with the sound then jetting the carb to the pipe. We all went through this process to get ours to run like we want. We go by spark plug color, you want the white center porsion to be light to medium brown in color. Search plug chop in the search box at the top of this page for a lot of info.
Greg from my own experience ill have to disagree about these engine running better with back pressure on exhaust, I have run many different exhaust configeration and have yet to find a single one of my engines that have not lost power and speed when I had much of any restriction on the exhaust, now a slight amount may help on the low end torque but medium to upper range power/speed has without exception increased on my bike when I open up the exhaust to flow freely, my testing is how well it pulls the hills. And the difference in top speed and maximum rpms, I can only attest to my own experiences of course but these have always been my results on all my china girl engines without exception.

Map
.wee.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
The plug is oily and black so I moved the clip on the small brass rod from the third to the top notch and then it wouldnt run at idle so I screwed the screw on the side in a half turn at a time until it would idle nice and smooth and it is almost all the way in but it runs much better than it was last night but it still doesnt have the power I think it should but I think replacing the plug should help alot since its pretty fouled. I also found out that my front wheel isnt quite true so it looks like ill be saving up for a wheelmaster wheel with sturmy archer drum and dynamo to kill 3 birds with 110 stones unless somebody knows of a decent wheel and brake package for a more reasonable price, again sorry for my ignorance but other than thicker spokes being better I dont know what makes one wheel better than another.


On a side note my dumb butt used my brake lever as a clutch lever for testing purposes so I was riding this morning at wot with no brake, must have taken a quarter inch off the sole of my boots to slow down.
Normally second notch from top it where clip on metering rod seems to work best for most engines, if the plug is running black and oily that can indicate a couple different things that can hurt power and how it runs overall, could be that oil mix is to rich on oil, I'd run no richer than 32:1 with a quality convensional 2 smoker oil and the other thing that will make the plug run black and oily is that the main jet in the carb is to big and causing the engine to run to rich on fuel.

Map
 

Greg58

Well-Known Member
May 1, 2011
5,353
2,575
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Newnan,Georgia
Map I was telling not to run without a exhaust, I run mine opened up some too but not so loud that it annoys the neighbors. I'm dealing with the 48cc so I have to help bottom end so I don't have to pedal as much.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
Map I was telling not to run without a exhaust, I run mine opened up some too but not so loud that it annoys the neighbors. I'm dealing with the 48cc so I have to help bottom end so I don't have to pedal as much.
Im sorry Greg I misunderstood, forgive me brother..... wasn't trying to be disrespectful .....

Its so hard to tell the intent or attitude of comments when only reading someones chicken scratch and I know I am bad at it sometimes....

Map
 

BigBlue

Member
Nov 29, 2011
781
0
16
California
What you need is a hop-up kit that increases your displacement to 55cc. Unfortunately, they are hard to find. It's possible a member might have one for sale.

Simpson Motor Bike has them listed on his site. I don't think his website has been updated in a while. He hasn't been active on the forum in a while. He was involved with EZ Motorbike.
http://www.simpsonmotorbikes.com/55cc Hop up Kit.html

Good Luck,

Chris
AKA: BigBlue