Was wondering if it was possible to just change the top end of the bike to a more readily available parts say a 49mm piston. I'm having trouble finding a 44mm wide piston. The reason I say this is because I cannot find a high compression head that will work with my engine I have 6mm studs. Any help?
Can i change piston and cylinder to a more universal one?
- Thread starter bioboi
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cloakedvillain
Well-Known Member
The CDH jog pipes help with low end 15-25mph riding. Although it will need a muffler for the sake of your hearing and preventing noise complaints. A low profile pod filter can also help by being less restrictive than the stock one on NT speed/JRL Bofeng carburators.
Dyno testing free mods, not my video:
Dyno testing free mods, not my video:
Your not gonna get what your looking to accomplish with a 48, 49cc motor unless you know how to deck the cylinder jug to adjust the squish factor for more compression.
Especially when your trying to turn that rear fat tire.
I've been reading on how to measure squish and all that with sodder. But I'm not going that deep into it all that. All I really wanted was a high compression head. Maybe a bigger piston. What my question is I guess is what size head would I need with the measurements I have. I have pictures of the measurements. Anytime I go looking for the head all the ads say is 69cc 80cc but no measurements.
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And they mean exactly what they say...Those heads will fit a 80/66cc motor...They will NOT fit on a 48/49cc motor...There is no universal, after market, "One size fits all" larger engine use heads that will fit for the 48/49cc motors, I do not know how to make this any clearer to you.
You have 6mm studs holding the head and cylinder jug together, the 80/66cc motors are 8mm studs...Also the spacing of the studs on yours are much closer together than on the larger motors.
If you want the type of power you are asking for, low end torque with high end top speed, your not gonna get it from that motor without going into a ton of modifications and work going into it that will cost you alot more than just buying something like a Phantom 85 motor, and then your gonna find out all the problems with trying to fit something larger than a 48/49cc into that kind of confined bike frame space your trying to work with.
cloakedvillain
Well-Known Member
You can tune and customize the bike for top end speed or for low end torque but you have to pick. The 48cc motors stock preform very closely to the stock 66cc variants. Supposedly the difference is between the two is a half horse at peak power. That's 350 watts, its really not that much compared to what it actually takes to move a bicycle. A healthy young man that rides often should be able to put around 160 watts into the pedals continuously at a so called "touring pace." That will make up the difference and get your blood pumping in the cold weather.
That extra 2mm or so of bore between them isn't significant. If you're having trouble with torque, gear it lower and take life slower. You're skin and bones, muscle and blood not a metal machine: a bad fall will ruin your body faster than you know what's even happening.
Money is tight for most and time is precious so I don't expect anything from you but you don't have a front brake.
That extra 2mm or so of bore between them isn't significant. If you're having trouble with torque, gear it lower and take life slower. You're skin and bones, muscle and blood not a metal machine: a bad fall will ruin your body faster than you know what's even happening.
Money is tight for most and time is precious so I don't expect anything from you but you don't have a front brake.
Yeh I dont have brakes one of the reasons I don't ride it just yet I've been trying to get everything spot on before I did. I've been ordering parts and am in the process of putting it together. Its cold right now here in Michigan. And I have another 4 stroke bike with brakes has torque converter and everything and runs really well had it for three years now going on four. I really don't ride them that often. I'm more of a tinker. And like having a hobby. Keeps me busy and looking forward to things. So its just fun for me and I like knowing that I have it. Im not in a rush to get things done just looking for answers. I've been looking at reed valves, different carbs, minarelli conversions and what not and since Its cold. I was already replacing gaskets clutch pads. So might as well start looking into upgrades. Also this engine is three years old just recently moved it to the chopper bike.
Chainlube
Well-Known Member
I just measured a Zeda 80 I have and the studs are 44mm apart.
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