49cc vs 66cc

metalliatic

metalliatic

New Member
whats the differance? bore? stroke? both? ive heard the 49cc is better for top speed but the 66cc is better for low end torque. is that true? all ive ever had is the 66cc.
 
i also have the 66 cc and i know a friend who has a 49 cc and i have a better top end as well as better torque however i have added a homemade boost bottle which works great.
 
My gen-2 49cc hits 33mph on flat ground riding past the police radar trailer.
It only went 25 and barely made it up hills until I put a pocket bike expansion chamber on it. now I don't even peddle up steep hills.
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49cc is a joke. The only reason that you should get one is if you are really worried about the law or if you are just going to putt around at a very slow speed. It has zero advantages over the ;arger motor.

I originally had one, as well as a shift kit for my bike. When I rode with other people my shift kit would allow me to take off a little faster, but even with my many gears I couldn't come close to the single speed 66c bikes.
 
i may be misinformed, but as i understand it the HT 66 and 49cc motors are the same bottom end with a different cylinder/piston on each. the 49 will rev higher for the same performance but im pretty sure thatsthe only difference. im only regurgitating info that i picked up when trying to decide for my bike. i could be wrong.
 
I have a one 62cc and one 69cc from dax, when i put them side by side there is a difference in ever aspect, the bottom end is smaller as well and the exchange ports are molded different as well as a smaller jug. The only thing that may be the same would be the mag and clutch covers. I had a 62 on my rock-hopper and didn't like the power much as i have always ran the 67cc, i recently swapt the motor out with a 67cc, the motor was larger and fit the bike better. Good luck
 
I currently have the 49cc, seems pretty slow, then again it's my first bike. I was curious how much more performance I would get vs the 66cc? Can I change the head into a 66cc?
 
can sombody measure the bore and stroke on thier 49cc for me? and ill let you know what my 66cc and my 68.5cc is and we can compare the differances. the maybe we can answer the common question of how to tell the differance between them.
 
vincent713 said:
I currently have the 49cc, seems pretty slow, then again it's my first bike. I was curious how much more performance I would get vs the 66cc? Can I change the head into a 66cc?
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Probably not. My first bike was a 49cc and I bought the 66cc head kit. It turns out that the flanges at the bottom of the head do not fit into the bottom end made for the 49cc, so there are subtle differences. I WAS able to upgrade the 49cc to a 55cc.

Interestingly enough my 55cc bike has a CNC carb on it and out performs my three other bikes, all of which have 66cc engines. Personally I write that off to the original motor just being well balanced to begin with due to "dumb luck."
 
I put a CNC Carb on it too. Then I replaced the crappy air filter that comes with the CNC carb with a K&N one. It also has one of the newer exhausts on it, the EPA certified ones, which I believe are less restrictive.

This sits on an Electra Coaster 7 frame which is a longer frame then usual and provides additional space for the carb and air filter.

Unfortunately I've had problems with the rear wheel warping on this bike since it has been using the old "rag joint" method of holding the drive gear to the wheel. I think that between that and the increased performance this engine seems to have the spokes (even heavy duty ones) can't hold up with me and my son's use (read abuse) of it. Currently it's down for repairs to the wheels. I have two other bikes that work fine, however.
 
wes said:
I have a one 62cc and one 69cc from dax, when i put them side by side there is a difference in ever aspect, the bottom end is smaller as well and the exchange ports are molded different as well as a smaller jug. The only thing that may be the same would be the mag and clutch covers. I had a 62 on my rock-hopper and didn't like the power much as i have always ran the 67cc, i recently swapt the motor out with a 67cc, the motor was larger and fit the bike better. Good luck
Click to expand...

wait- the thread is 49cc vs. 66cc. You just mentioned a 62cc ( news to me) , and your 69cc. then you go back to the 62, and then the ever-so-popular old faithful 67cc. so just how many sizes do you have? 49, 62,66, 67,& 69? is there a 71cc somewhere? cause that's the year I was born and it would probably run real smooth if you know where i could get one...I suppose you were right by saying "good luck".

P.S. is Dax selling more of that "wacky tobacky" as well?
 
Have a 66 and a 50 cc- actually a 55 I guess-

The 66 is definely stronger, and I think more standard replacement parts these days.

The 50 is quieter, needs both a little more pedal to get going and not such a high end speed- still it is lighter and on a light bike makes a nice little get around-
mines not carburted well and I'm 4 stroking almost all the time- I put another jug on it with a billet intake and a normal kit carb- the other is a "Sleeve carb and different stud width AND a different jet I can't repace-

anyway, the new lighter jug and carb ran REALLY GREAT- noticibly better when I started off-
something got in there though- I'm not sure- it didn't look like it was a piston ring piece- and scoured the cylinder wall- so I'm back with the original jug and carb

I was going to try to upend it- it seemed like on boygofast that the needle bearing and rod were interchangeble and he sells a 66 head with rings and piston complete, and then i could use the billet and regulart bored carb with a bigger jet-

but after reading several posts above I'm now not sure if the bottom end would fit- I never was- I'll probably get another jug for the 50 cc so I can use the billet, but no hurry- it's rolling around nicely at about 25, and I'm riding it more right now-

ready to install that 415 lightweight trike chain I posted about here.
 
Actually thinking back I'm wondering about the photos above -

my head and jug look just like the ones listed as 55cc- but I measured the piston a few weeks back and it measured EXACTLY 40mm- I posted a query here as to the width of a 66- not wanting to take mine apart- and the answer from somebody else was 45 I think.

so I'm not sure if the picture is that acurate- at least my square head and that kind of jug has a piaston 40mm.

I think the stroke is the same they seem to advertise the same connecting rod on ebay- but you know how information is on all this- plus through the years they've shipped varients and people talk about them here

My 66 is almost 3 years old now- and has 6 mm studs- I think 8mm is pretty standard now.
 
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