Can you unbridled your 48cc engine ?

this guy with the big words......


I wouldn't say these engines are "bridled" as much as they are extremely cheaply made. Don't get me wrong For ~130 bucks your getting a **** of a deal. like some moped engines which have a restrictive intake that allows the moped to pass regulations and still haul with minor modifications. This is not to say you cant get a small power increase with DIY mods and cheap upgrades.

First things first, replace your spark plug wire(~$8), if your spark plug came with no nipple on it buy an NGK B6HS(~$4), its arguably the best all around plug for most conditions. This will really keep it from sputtering at higher rpms, starts will be easier and it will idle far better.

If i would consider anything a bridle it would be the stock air box. Some of the grubees come with a red one which is not as restrictive, but if you get a black one drill a bunch of holes in it to take away some of the vacuum at higher speeds.

Go with a fully synthetic oil(not a blend). -Increases all around engine performance.

Increase your compression by removing your head gasket or base gasket depending on where you want your power. Remove the head gasket if you want a little more power all around. If torque is a big issue, remove the base gasket(it changes the valve timing in favor of low end torque). I say or because most engines will hit the top of the head if both are removed, but if you try it with both and the piston doesn't hit the plug or head (and your willing to take the slight risk) go ahead and take off both gaskets. If you want your engine to stay clean but some gasket spray, its about 8 bucks but
its good stuff. I have no head or base gasket and my engine has had no leaks for 400 miles.


Though it takes a little longer, matching your exhaust port with your exhaust flange using a rotary grinder or a file can help as well. If your really willing to dig into you engine you can match the transfer ports as well as the intake side.


Just my two cents, 90 percent of my customers who buy 50ccs want to replace them with 80s after they try out my bike( i started with a 50 as well). They have at least twice the torque as the 50s and about a third more power even at the high rpm. And no cop carrys around a syringe to measure displacements so don't worry about the 50cc and under law.


Either way your gonna love it.

No way, as long as you wear a helmet and dont be a jackass on the road, cops leave you alone. I have been pulled over once because in Virginia you need to have a windscreen type helmet. that was 8 months ago and i haven't bought a new one... still no problems though.

in conclusion, they will have no way of telling what displacement your engine is as long as you remove the sticker on the side. Even then they normally don't care.

One more thing: I always push this, but from talking personally to a cop here: make sure you have a proper helmet and working lights and a mirror. It is cheap and just good sense for riding in imperfect conditions and may stop you from getting pulled over.

Well, on the motors: if you get the "80cc" it is actually a 60-something cc motor, not what they advertise it as. The difference in piston size etc is definitely small enough that no-one could tell without taking the motor apart and measuring it. You should have no worries about motor size if you get pulled over and you will have more torque and a bit more power, which counts on these, especially if you keep it stock with the one-speed drive.

I would say $200 is a good amount. With that I would buy:

80cc Motor and and Kit from ebay, I have had good experiences with a seller called "luckyearlybird", but ask around if you like. $130, free shipping.

Walmart bicycle light set, front and rear, $30, plus batteries, $5.

Walmart bar-end Mirror, $6.

(Now we go into acessories, things that aren't necessary but make it easier to ride)

Walmart sprung cruiser seat, $25

and/or

Walmart bike bag for tools or a spare tube

Finally, if you are travelling long distances I would get a larger fuel tank, or a rear rack and an auxiliary tank.

Even getting all of that, the cost should be about $210, minus what you paid for the bicycle.

On speed, it should get around 30mph cruising, completely stock. Modifying the motor and maybe adding a smaller sprocket, among other things, could increase the speed but it requires time, money, or tools and sometimes all three. See the "high performance engine tips" section of the forum for help on speed.

i ran a cheapo centerfire first gen with no basegasket and was actually quite please with its increase....

its all about measurement.


in other words, if you dont know, dont guess.

BTW i recently bought and built a 49cc pk. Dont like it one bit, its even more gutless than the 80's are off the get go.... just get the bigblock and be done

Yes I also say go Slant head 80/66cc with improved exhaust and just run the crap out of it, I use a 41T sprocket because of the hills around where I live and my bike does about 37 WOT and cruises nice @ 28-30MPH.

be careful !!!
the law in AZ is 48cc, pedals, and 20mph
here is a link to the law that defines and governs MB's
28-2516 - Motorized electric or gas powered bicycles or tricycles; definition
I carry a copy with me

azbill said:

be careful !!!
the law in AZ is 48cc, pedals, and 20mph
here is a link to the law that defines and governs MB's
28-2516 - Motorized electric or gas powered bicycles or tricycles; definition
I carry a copy with me

Click to expand...

Yes but again... cops CANNOT tell if the motor is 48cc or 65(80)cc. It does not matter in that respect and the 65cc has better power.

Hope-Dasher. Screw you and your common sense.

hahaha

actually...
some cops can tell the difference !!!
there is at least one member here who is a officer

mostly I was bringing up the 20mph limit
people have gotten hit for being a moped (no plate, insurance, license...big fines)

Yea by valves i meant ports....

And Map is right if you want to stay completely safe don't remove the gaskets. I can tell you, however that i have removed base gaskets on 3 engines and haven't had leaks on any of them (using the copper gasket maker). Head gaskets I almost always remove, normally they leak very slowly or not at all, but since i used the spray a gasket i haven't had any problems.

My first engine was a Raw motors 50cc. I was extrememly happy with it untill i tried a pk80 on a freinds bike. I am converting my 15th bike today and i can tell you that even after 3000 miles that raw engine is the best 50cc I've seen so far.

so if you are determined to stay legal, ideally id go with a raw, iv installed 2 Raws and 8 PKs, the PKs are inconsistent, both of the Raws are at least as good as the best pk.

If you don't want to be able to go 20mph(???!?!?!??!)... Id still get an 80cc and idk epoxy a washer on the intake to make it 4mm id.

like i said you'll be happy with whatever you get, Ive never had someone ride one of these for the first time and not have a smile on their face.

Samy, yes, I am an EZM dealer
I have an auto (Q-Matic) installed in my stretch cruiser
I have a build thread here
http://motorbicycling.com/f40/azbills-ezm-stretch-project-14760.html

if you can get out to my place in FH,
I have a standing offer on test rides