Plz Help. Need to make my bike faster and better

O

Octavio Romero

Guest
I built my bike about a month or 2 ago. Here's basically my setup:
Bike: Roadmaster Granite Peak from walmart
Kit: Flying horse silver angle fire ($130)
Carb: Hp
Sprocket: 36t (hub mounted)
Max speed:33mph on flat road
I am using pretty much all that came with the engine kit except for the carb and sprocket. I just recently upgraded to the hp carb and switchet its jet for the one in the stock carb. I got different intake manifold because the hp carb doesnt fit in the frame with the other one, so I now use an offset one. I noticed however that the port into the intake manifold is smaller than the port into the engine. Before I changed my carb, I was hitting around 30-33mph more and more easily. Now, I can't seem to hit 30 as easily. I also ride with the baffle cap out just because I like the loudness. I was thinking about getting a better spark plug from like autozone and also buying an f2 thruster exhaust from amazon.


I really want to hit 40, even 50mph, but I honestly don't know how, which is why I came here for advice and help. I've seen people say that a 26t will help you with that but I put loctite on my sprocket and hub adapter, so it would be pretty hard to take those off considering I have no blowtorch or other hearing device. I would really appreciate help from anyone.
 
Links to Amazon may include affiliate code. If you click on an Amazon link and make a purchase, this forum may earn a small commission.
if i had a 36t i could make it to 45mph i modded this banana pipe and put a header on it and a stinger myself with a welder and a head and ngk plug. Anyway i have a stock motor on another 700c 29inch bike completely original stock kit with a 36 tooth on it and it goes 43mph with no issues never wanted to go faster but it still had more in it probably could reach 50mph if i had a pipe for it.
86183
 
set your carb to a one notch leaner and see if you get a higher top speed thats what i have done with my motors helps alot
 
I built my bike about a month or 2 ago. Here's basically my setup:
Bike: Roadmaster Granite Peak from walmart
Kit: Flying horse silver angle fire ($130)
Carb: Hp
Sprocket: 36t (hub mounted)
Max speed:33mph on flat road
I am using pretty much all that came with the engine kit except for the carb and sprocket. I just recently upgraded to the hp carb and switchet its jet for the one in the stock carb. I got different intake manifold because the hp carb doesnt fit in the frame with the other one, so I now use an offset one. I noticed however that the port into the intake manifold is smaller than the port into the engine. Before I changed my carb, I was hitting around 30-33mph more and more easily. Now, I can't seem to hit 30 as easily. I also ride with the baffle cap out just because I like the loudness. I was thinking about getting a better spark plug from like autozone and also buying an f2 thruster exhaust https://www.amazon.com/Tuning-Performance-Thrust-Exhaust-Muffler/dp/B01N5T44RW from amazon.

I really want to hit 40, even 50mph, but I honestly don't know how, which is why I came here for advice and help. I've seen people say that a 26t will help you with that but I put loctite on my sprocket and hub adapter, so it would be pretty hard to take those off considering I have no blowtorch or other hearing device. I would really appreciate help from anyone.
port match, thats what i did with mine, hit 38mph, i didnt nothing else.
have you removed the baffle? that should really make it fly!
i would get your self a pin vice and a soldering iron (aka poor mans jetting kit)

this is the soldering iron i use. bit pricey but its lasted me for 4 years!


 
Last edited:
Links to eBay may include affiliate code. If you click on an eBay link and make a purchase, this forum may earn a small commission.
Links to Amazon may include affiliate code. If you click on an Amazon link and make a purchase, this forum may earn a small commission.
Yes the key is to get the pk80 or 40mm stroke motor more power than the 38mm. I used to go 37mph with that. Mz Miami expansion chamber or the zeda 88 will help too. I’m pretty much a 4 stroke guy now/ Japanese 2 stroke guy.
 
There are a lot of little things you can do to get more speed from a stock kit, but a stock kit on a 26" tire won't go over 41-42mph without an expansion chamber. Also, keep in mind that long offset intake helps low end but is worse for top end. I was bored a while back and wanted to see how fast a stock kit can go with some tricks so messed around with it as a project for a while. This is what I did for a 42mph setup with only kit parts(nothing purchased besides a spark plug) and no real porting(just gasket matching).

Started with a Triple40, which is already a lot faster than the older 6mm stud/32mm intake kits and comes with a 36t vs 44t. Bike was a 26" Hyper cruiser.
  • Match transfers between the jug and bottom end. They are out of alignment and casting shift can make some very small - this is worth a ton
  • Deburred all ports and matched intake to intake gasket and exhaust to the larger round brass gasket(but used stock exhaust gasket still, just cut it to match)
  • NGK plug @ .030"
  • Second wire wrapped around plug wire and soldered onto boot/spliced into CDI side (stock plug wire is super thin, if you remove it only 5-6 thin single strands of wire are actually in it!)
  • Drilled out center of air filter housing for more airflow
  • Single base gasket, aiming for ~165psi compression
  • Smoothed and polished head chamber to prevent hot spots and build-up the the rough crappy surface. There is sometimes a sharp raised "o" mark in the chamber from casting that needs to be removed to prevent hot spots. Some 150 grit sandpaper gets it done by hand in no time, no tools needed. Didn't actually remove material since that will lower compression, just cleaned up the chamber to make it smooth. Also do NOT mill the squish band for more compression if you are running a single base gasket since as the motor breaks in the piston will eventually start to hit the squish band on the head and then you will need a thicker head gasket.
  • Cut exhaust baffle tube flush with end cap. Still kept end cap on since I think it sounds horrible with it removed and honestly without an expansion chamber the difference between cut flush baffle and no end cap wasn't very noticeable.

My goal was 45mph on a stock kit, but while porting to get the last 2 mph I gouged the cylinder and it slowed down to 38mph so I gave up. Can't find the 42mph screenshot but this was a 41mph one.
86198


Have pics of everything done if you have any questions.

If you really want to go fast, do the above then add a VM18 with shorty intake and an MZ65. You will do ~55mph.
 
There are a lot of little things you can do to get more speed from a stock kit, but a stock kit on a 26" tire won't go over 41-42mph without an expansion chamber. Also, keep in mind that long offset intake helps low end but is worse for top end. I was bored a while back and wanted to see how fast a stock kit can go with some tricks so messed around with it as a project for a while. This is what I did for a 42mph setup with only kit parts(nothing purchased besides a spark plug) and no real porting(just gasket matching).

Started with a Triple40, which is already a lot faster than the older 6mm stud/32mm intake kits and comes with a 36t vs 44t. Bike was a 26" Hyper cruiser.
  • Match transfers between the jug and bottom end. They are out of alignment and casting shift can make some very small - this is worth a ton
  • Deburred all ports and matched intake to intake gasket and exhaust to the larger round brass gasket(but used stock exhaust gasket still, just cut it to match)
  • NGK plug @ .030"
  • Second wire wrapped around plug wire and soldered onto boot/spliced into CDI side (stock plug wire is super thin, if you remove it only 5-6 thin single strands of wire are actually in it!)
  • Drilled out center of air filter housing for more airflow
  • Single base gasket, aiming for ~165psi compression
  • Smoothed and polished head chamber to prevent hot spots and build-up the the rough crappy surface. There is sometimes a sharp raised "o" mark in the chamber from casting that needs to be removed to prevent hot spots. Some 150 grit sandpaper gets it done by hand in no time, no tools needed. Didn't actually remove material since that will lower compression, just cleaned up the chamber to make it smooth. Also do NOT mill the squish band for more compression if you are running a single base gasket since as the motor breaks in the piston will eventually start to hit the squish band on the head and then you will need a thicker head gasket.
  • Cut exhaust baffle tube flush with end cap. Still kept end cap on since I think it sounds horrible with it removed and honestly without an expansion chamber the difference between cut flush baffle and no end cap wasn't very noticeable.

My goal was 45mph on a stock kit, but while porting to get the last 2 mph I gouged the cylinder and it slowed down to 38mph so I gave up. Can't find the 42mph screenshot but this was a 41mph one.
View attachment 86198

Have pics of everything done if you have any questions.

If you really want to go fast, do the above then add a VM18 with shorty intake and an MZ65. You will do ~55mph.
Yeah, could u send pics of the above things cuz i don't understand half of what you're talking about.
 
There are a lot of little things you can do to get more speed from a stock kit, but a stock kit on a 26" tire won't go over 41-42mph without an expansion chamber. Also, keep in mind that long offset intake helps low end but is worse for top end. I was bored a while back and wanted to see how fast a stock kit can go with some tricks so messed around with it as a project for a while. This is what I did for a 42mph setup with only kit parts(nothing purchased besides a spark plug) and no real porting(just gasket matching).

Started with a Triple40, which is already a lot faster than the older 6mm stud/32mm intake kits and comes with a 36t vs 44t. Bike was a 26" Hyper cruiser.
  • Match transfers between the jug and bottom end. They are out of alignment and casting shift can make some very small - this is worth a ton
  • Deburred all ports and matched intake to intake gasket and exhaust to the larger round brass gasket(but used stock exhaust gasket still, just cut it to match)
  • NGK plug @ .030"
  • Second wire wrapped around plug wire and soldered onto boot/spliced into CDI side (stock plug wire is super thin, if you remove it only 5-6 thin single strands of wire are actually in it!)
  • Drilled out center of air filter housing for more airflow
  • Single base gasket, aiming for ~165psi compression
  • Smoothed and polished head chamber to prevent hot spots and build-up the the rough crappy surface. There is sometimes a sharp raised "o" mark in the chamber from casting that needs to be removed to prevent hot spots. Some 150 grit sandpaper gets it done by hand in no time, no tools needed. Didn't actually remove material since that will lower compression, just cleaned up the chamber to make it smooth. Also do NOT mill the squish band for more compression if you are running a single base gasket since as the motor breaks in the piston will eventually start to hit the squish band on the head and then you will need a thicker head gasket.
  • Cut exhaust baffle tube flush with end cap. Still kept end cap on since I think it sounds horrible with it removed and honestly without an expansion chamber the difference between cut flush baffle and no end cap wasn't very noticeable.
My goal was 45mph on a stock kit, but while porting to get the last 2 mph I gouged the cylinder and it slowed down to 38mph so I gave up. Can't find the 42mph screenshot but this was a 41mph one.
View attachment 86198

Have pics of everything done if you have any questions.

If you really want to go fast, do the above then add a VM18 with shorty intake and an MZ65. You will do ~55mph.
s**t your already going over Max if I could do 42 mph I would be so happy I would cry.
You might try a different tire style I pick up a couple mph changing style make sure of your tire pressure lube the chain reduce friction drag.
 
Back
Top