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Have A 2 Stroke A/C Pocketbike & Want To Make It Faster?????....Look Here If You Do..
So you have a cheap 2 stroker bike thats in need of some more power........Theres no real mystery to it and its quite general for most pocketbike engines like cags and x1's where both have different types of two stroker engines...
This Thread outlines JUST the D.I.Y mods aswell as Basic mods you can do to enhance power ......This thread does not cover porting or blueprinting.....Theres threads that outline the blueprinting and porting process and requires an attention to detail aswell as a dremel set fully loaded with assorted cutters/grinders...
...............................If you have an engine like this one.......................
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...................................Here are the mods........................................
Change the Fuellines and In-Tank Fuel Clunker..........If the fuel in the tank is old ....remove the tank and wash it out with hot water ans dish soap then dry it out thoroughly........
Get rid of stock airfilter and get a velocity stack w/ built-in choke and a hp airfilter.....Now youre gonna ask where....??? Check out the PBP vendor supplier section for more info.....Usual cost for a setup is around $20 bux shipped.....I like to use ebay.........
There is also a DIY mod utilizing a laundry detergent bottle cap and some pantyhose...You use the palm of your hand as the choke... or if your handy can add a choke flap by removing the one from the stock airbox and rigging it to work........Cost of this Mod...maybe $2 bucks and 30 mins time.........
Just know that when you improve airflow intake youll be leaning out the engine severely so therefore some carb tuning may be required.......If you have a Walbro carb you have Lowspeed and Highspeed needles screws on the side of the carb that do almost the same thing the same way..
Heres a video for tuning the stock 15mm WYK carb.........
http://s709.photobucket.com/albums/...oke stock carb/?action=view¤t=004-3.mp4
Walbro WT813 HP Pumper Carb Upgrade............. Using this carb will require you use an adapter plate or you mod the stock intake with JB Weld...Cost of this upgrade varies from $32.99-$50 bux...
JUST AS A NOTE>>>>>>>>>>>>....................I suggest you using new gaskets between the insulator block and engine aswell as between the carb too....Never trust old gaskets in this area and NEVER use RTV sealants!.. If youre handy you can buy a rolled sheet or rubber fibre material thats .025" thick to make new gaskets with.........
Lighten the flywheel by clipping the fins 3/8" shorter to reduce fin drag and reduce reciprocating weight....cost of this mod....30 mins of your time with a hacksaw ,,sandpaper and a file
Unmodded Flywheel......
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Modded Flywheel..............
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Add a rocket key.....Alot ask does it work and is it worth the effort and the money....The answer is YES....cost of this mod is under $10 bux..Daves Discount Motors is the best place to get them...You want the LARGE rocket key.............
For more info about the way to install it heres a thread..... http://www.pocketbikeplanet.com/showthread.php?t=79475
Modify the Clutch.......This is done by crossdrilling the pads ,,adding a hp clutchspring,,deglazing the clutchpads and clutchbell with 100 grit sandpaper and deoxidize/de-rust clutch mount bolt shoulders and mount holes on the pads..When you reinstall the clutchpads make sure you use loctite on the screws.........cost of this mod.......30 mins labor with a handdrill,,some sandpaper,,metal polish and of course threadlocker.....
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Get a quality brand sparkplug........NGK BPMR7A plug gap is between .030" to .035"
JUST AS A NOTE>>>>>>................ After you reinstall the coil after modding the flywheel/adding a rocket key and modding the clutches it will have to begapped properly......This is done using a business card that a true .020" thick........most use index card shreds but it has to be atleast .020" thick to maximum .024" thick....
DIY Boostbottle Setup............ Alot ask if boost bottles work and worth the effort......?.....The answer is YES....Theres many-many threads on what boost bottles do and how to make them..Do a search for past threads on the subject....I personally use them and get great results from the ones Ive built myself..
Get a Performance Exhaust...Theres JetPro pipes,,rev pipes and fatty pipes for these kind of engines,,The JetPro and Fatty pipes offer the best performance gains.........cost of this mod varies by model of bike and is between ...$39-$80..sometimes ebay has the ebst deals on exhausts..
Remove the Electric Starter/Generator,,Battery,,Wiring,,Switches.... Removing them has alot of benefits.....Heres a thread on the subject.... http://www.pocketbikeplanet.com/showthread.php?t=58861
Change the Gearing...... To gain more topend speeds you can either get a front sprocket thats 1-2 teeth larger or a rear sprocket between 6 and 10 teeth smaller...Seeings its easier to change the front sprocket Id go with that..
JUST An ENDNOTE>>>>>>>>>>.... Speeds and performance given will vary but will definately give you a noticeable improvement over being bone stock if done right..............If more power is desired I suggest you break out your dremel and learn how to use it well...
So you have a cheap 2 stroker bike thats in need of some more power........Theres no real mystery to it and its quite general for most pocketbike engines like cags and x1's where both have different types of two stroker engines...
This Thread outlines JUST the D.I.Y mods aswell as Basic mods you can do to enhance power ......This thread does not cover porting or blueprinting.....Theres threads that outline the blueprinting and porting process and requires an attention to detail aswell as a dremel set fully loaded with assorted cutters/grinders...
...............................If you have an engine like this one.......................
...................................Here are the mods........................................
Change the Fuellines and In-Tank Fuel Clunker..........If the fuel in the tank is old ....remove the tank and wash it out with hot water ans dish soap then dry it out thoroughly........
Get rid of stock airfilter and get a velocity stack w/ built-in choke and a hp airfilter.....Now youre gonna ask where....??? Check out the PBP vendor supplier section for more info.....Usual cost for a setup is around $20 bux shipped.....I like to use ebay.........
There is also a DIY mod utilizing a laundry detergent bottle cap and some pantyhose...You use the palm of your hand as the choke... or if your handy can add a choke flap by removing the one from the stock airbox and rigging it to work........Cost of this Mod...maybe $2 bucks and 30 mins time.........
Just know that when you improve airflow intake youll be leaning out the engine severely so therefore some carb tuning may be required.......If you have a Walbro carb you have Lowspeed and Highspeed needles screws on the side of the carb that do almost the same thing the same way..
Heres a video for tuning the stock 15mm WYK carb.........
http://s709.photobucket.com/albums/...oke stock carb/?action=view¤t=004-3.mp4
Walbro WT813 HP Pumper Carb Upgrade............. Using this carb will require you use an adapter plate or you mod the stock intake with JB Weld...Cost of this upgrade varies from $32.99-$50 bux...
JUST AS A NOTE>>>>>>>>>>>>....................I suggest you using new gaskets between the insulator block and engine aswell as between the carb too....Never trust old gaskets in this area and NEVER use RTV sealants!.. If youre handy you can buy a rolled sheet or rubber fibre material thats .025" thick to make new gaskets with.........
Lighten the flywheel by clipping the fins 3/8" shorter to reduce fin drag and reduce reciprocating weight....cost of this mod....30 mins of your time with a hacksaw ,,sandpaper and a file
Unmodded Flywheel......
Modded Flywheel..............
Add a rocket key.....Alot ask does it work and is it worth the effort and the money....The answer is YES....cost of this mod is under $10 bux..Daves Discount Motors is the best place to get them...You want the LARGE rocket key.............
For more info about the way to install it heres a thread..... http://www.pocketbikeplanet.com/showthread.php?t=79475
Modify the Clutch.......This is done by crossdrilling the pads ,,adding a hp clutchspring,,deglazing the clutchpads and clutchbell with 100 grit sandpaper and deoxidize/de-rust clutch mount bolt shoulders and mount holes on the pads..When you reinstall the clutchpads make sure you use loctite on the screws.........cost of this mod.......30 mins labor with a handdrill,,some sandpaper,,metal polish and of course threadlocker.....
Get a quality brand sparkplug........NGK BPMR7A plug gap is between .030" to .035"
JUST AS A NOTE>>>>>>................ After you reinstall the coil after modding the flywheel/adding a rocket key and modding the clutches it will have to begapped properly......This is done using a business card that a true .020" thick........most use index card shreds but it has to be atleast .020" thick to maximum .024" thick....
DIY Boostbottle Setup............ Alot ask if boost bottles work and worth the effort......?.....The answer is YES....Theres many-many threads on what boost bottles do and how to make them..Do a search for past threads on the subject....I personally use them and get great results from the ones Ive built myself..
Get a Performance Exhaust...Theres JetPro pipes,,rev pipes and fatty pipes for these kind of engines,,The JetPro and Fatty pipes offer the best performance gains.........cost of this mod varies by model of bike and is between ...$39-$80..sometimes ebay has the ebst deals on exhausts..
Remove the Electric Starter/Generator,,Battery,,Wiring,,Switches.... Removing them has alot of benefits.....Heres a thread on the subject.... http://www.pocketbikeplanet.com/showthread.php?t=58861
Change the Gearing...... To gain more topend speeds you can either get a front sprocket thats 1-2 teeth larger or a rear sprocket between 6 and 10 teeth smaller...Seeings its easier to change the front sprocket Id go with that..
JUST An ENDNOTE>>>>>>>>>>.... Speeds and performance given will vary but will definately give you a noticeable improvement over being bone stock if done right..............If more power is desired I suggest you break out your dremel and learn how to use it well...
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