What should I install next?

Chris7420

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Jul 23, 2021
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Wow, 52mm bore, that's got to be pretty fast. That's something new, don't know how good they are but it's got to have more torque than standard China girls. But to be honest, my bike goes fast enough, I can hit 50+ mph if I really wind it up, but really, I don't need to go that fast on a bicycle.
That’s wicked man. Mine goes 50 KMH winded out.
 

Testname111

Active Member
May 20, 2021
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Try new electrical system, I'm using bbr super magneto and stage 2 Cdi with a car ignition coil ;)



 
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Testname111

Active Member
May 20, 2021
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Ive thought about installing a reed valve but I’ve read a lot of bad reviews on reed valves of people saying they installed one and it made they’re bike slower, I even saw a video of a guy who dyno’d an engine before and after installing a reed valve and it made like half as much power.
Can I take my reed out of my Athena cylinder to go faster?

[
 

Chris7420

Member
Jul 23, 2021
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Try new electrical system, I'm using bbr super magneto and stage 2 Cdi with a car ignition coil ;)



Does it make a difference? Did you’re bike go faster after installing those?
 
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Tyler6357

Well-Known Member
Mar 15, 2012
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Santa Barbara, CA
Try new electrical system, I'm using bbr super magneto and stage 2 Cdi with a car ignition coil ;)



Did you get a performance increase using that?
 

Chris7420

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Jul 23, 2021
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This is the reed valve that I got:


They don't really show you the 4 peddles but they look just like this:


I also got a windowed piston similar to this:




I also got one of these larger intakes for it to fit my Mikuni vm18 carb.

I ordered a reed valve and am trying to find a window piston, do you know if this will work? It’s says it’s 47mm and has high wrist pin. I know my engine is 47mm bore and type b wrist pin. https://www.ebay.com/itm/402186052573?hash=item5da42823dd:g:PgEAAOSwsvVeHhYA
 

Tyler6357

Well-Known Member
Mar 15, 2012
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Santa Barbara, CA
I ordered a reed valve and am trying to find a window piston, do you know if this will work? It’s says it’s 47mm and has high wrist pin. I know my engine is 47mm bore and type b wrist pin. https://www.ebay.com/itm/402186052573?hash=item5da42823dd:g:PgEAAOSwsvVeHhYA
That looks like the right one, although I don't know how good those double windowed ones work, I got one with the large window. I guess it would be okay, I'm just saying I've never tried those. I saw this one with the large window but it says 48mm instead of 47mm, I wonder if it's really a different size or maybe a typo.


You can always get a non windowed piston and just cut your own. Just install the piston and after you get the cylinder on use a sharpie and put it though the intake and mark the piston, then remove the piston and cut it with a Dremel tool.
 

Chris7420

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Jul 23, 2021
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That looks like the right one, although I don't know how good those double windowed ones work, I got one with the large window. I guess it would be okay, I'm just saying I've never tried those. I saw this one with the large window but it says 48mm instead of 47mm, I wonder if it's really a different size or maybe a typo.


You can always get a non windowed piston and just cut your own. Just install the piston and after you get the cylinder on use a sharpie and put it though the intake and mark the piston, then remove the piston and cut it with a Dremel tool.
Does the window piston really make a difference? I got the reed valve got it all installed, I didn’t change jets or anything just bolted on the reed valve it seems to run good how it is maybe a little lean I have to get a new spark plug and run it a little bit so I can read it. It has a little bit more power and it goes 5km faster now at WOT and it doesn’t 4 stroke at all anymore even at WOT which is nice but yea I thought it would get me going a little faster, I want it to 50 km/h without winding out the engine so I can keep up with traffic.
 

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Testname111

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May 20, 2021
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I think only way is with a carb that has a bigger intake slide/barrel slide hole.. Demintions more air in = more out saying?
 

Chris7420

Member
Jul 23, 2021
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That looks like the right one, although I don't know how good those double windowed ones work, I got one with the large window. I guess it would be okay, I'm just saying I've never tried those. I saw this one with the large window but it says 48mm instead of 47mm, I wonder if it's really a different size or maybe a typo.


You can always get a non windowed piston and just cut your own. Just install the piston and after you get the cylinder on use a sharpie and put it though the intake and mark the piston, then remove the piston and cut it with a Dremel tool.
Can you confirm if it’s the window piston or the better carburetor that got you’re bike going faster?