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Ninja Racer
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2,767 Posts
Discussion Starter #1
i have a zpf bike and im trying to teach young kids how to ride and the throttle control is killing them, they keep over reving by accident
so i remember when i was at a track this dude had a pb that wouldnt even move till it was like 3k rpm
i was thinking that might help
 

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But who prays for Satan?
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6,571 Posts
i have a zpf bike and im trying to teach young kids how to ride and the throttle control is killing them, they keep over reving by accident
so i remember when i was at a track this dude had a pb that wouldnt even move till it was like 3k rpm
i was thinking that might help
Keep the clutch set high, but....

raise the squish, to LOWER the power for the little dudeZ
 

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Ninja Racer
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2,767 Posts
Discussion Starter #3
so then dial out the compression
i noticed when my ex pipe nut came loose at the head it lost ome power
so should i take it apart and add another base gasket or maybe an extra washer in the sparkplug hole
YouTube - ‪Naythuns first pb ride‬‏
 

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But who prays for Satan?
Joined
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6,571 Posts
so then dial out the compression
i noticed when my ex pipe nut came loose at the head it lost ome power
so should i take it apart and add another base gasket or maybe an extra washer in the sparkplug hole
YouTube - ‪Naythuns first pb ride‬‏
Killing some spark would work too but Al Gore wouldn't like that, more oil and what not...

Just double up on the base gasket, the squish is really LOW on nice bikes, so get it up to China Spec, like my C1 was!

ps

BEST VIDEO EVeR Watch it and Thumbs up it or I WILL BAN YOU!!!!!! Just kidding, but please do go watch it, and at least have 1 FREE smile!
 

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Ninja Racer
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2,767 Posts
Discussion Starter #5
thanks nick it was really nice to see him so happy
his 1 yr younger brother did 2 'flip the bike wheelies' by mistake trying to take off and his heart wasnt in it after that, but naythun did real good
ok so ill do the base gasket, can i cut it from a roll i already have? and then just reassemble
 

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But who prays for Satan?
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6,571 Posts
thanks nick it was really nice to see him so happy
his 1 yr younger brother did 2 'flip the bike wheelies' by mistake trying to take off and his heart wasnt in it after that, but naythun did real good
ok so ill do the base gasket, can i cut it from a roll i already have? and then just reassemble
Cut it to the same shape, and it will be just FiNe.
 

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Premium Member
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6,162 Posts
You may just need to teach them to get their weight forward on the bike before they hit the throttle to keep it down.
As far as I would go on the clutch engagment would be about +/-7000RPM'S. Theres a exhaust plate thats used for juniors riders and a insert for the rubber manifold that makes the bore of the carb smaller to take some power away from the bike also that you can do.
 

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Ninja Racer
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2,767 Posts
Discussion Starter #8
well man i already took it apart
look at that roller bearing that goes inside the crank piston pin, awesome
my piston has two rings, any preference on their orentiation?
 

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But who prays for Satan?
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6,571 Posts
Find the "locating" pins, they are sometimes staggered a bit, and the ring gap usually point's to the exhaust I think, but I don't have any engines quite like that one!

ps

Good job "Diving right in" the water is cold at first, but we adapt really quick!

It's gonna be easier next time too!
 

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Ninja Racer
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2,767 Posts
Discussion Starter #10
ok now im at work and i cut 2 gaskets to use as a base and i notice that the freakin bike came with what looks 2 samwiched together
so now i wonder if my 2 i cut wil help or should i make one out of aluminum or sheetmetal, i have both
i got a roll of the good felpro btw
my camera is acting very wierd or id take some pics
id hate to do something permnant
but i thought of shaving a bit off the top of the piston
 

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But who prays for Satan?
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6,571 Posts
I'd stick with paper, but 2 .7 base gaskets made our orange c1's squish 1.4mm or something silly, but I think that nice bike, is already gonna be down at like .5 or .6mm

Double the squish = half the compression! dang that pesky math! I would quote numbers but I'm not good at math, but it's like going from 15:1 down to 7.5:1 which should be a noticeable difference.

Brady is totally right about the riding position too, the stall speed is setup HIGH :eek: for the motoGP type take off speed! so, EVEN I have to lean WAY over, or I get tossed off the bike (narrow PowerBand)

This is gonna sound CRAZY but.... what about gearing it "Taller" to make is less dangerous down low? one tooth up front would help, two teeth up front should tame it down for them, but WOT will get the little dudes do'in 55 or 60mph :p
 

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Ninja Racer
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2,767 Posts
Discussion Starter #12
i thoght of one tooth in the front, thats still available
the bike is really fine for me but you dont put a novice rider on a busa, and to them thats what it feels like
i thought of putting a plate in the throttle to limit that but even halfway will get you going so i went with total killing of compression, i doubled up on the base gasket
it back together and ready to start but its too late here, does anyone know what the headbolts torque specs are, any specs are fine if their true, i need a ball park
 

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Ninja Racer
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2,767 Posts
Discussion Starter #14
ok so i forgot to mention that my air box was just a plastic box with nothing inside, i was expecting some foam or something but its empty
air comes 2 small holes and isnt filtered at all
i finally found out what my idle screw does, it makes this airelon thingy move up or down slightly
man those freakin piston rings had me heated up for a bit
i didnt know there was two small dimples in the ring groove where the gap had to go, i kept trying to do it normall, then i thought ill take the piston off the rod and slide it in through the top of the cylinder, after a bit of that not working i noticed the dimples
i was mad, i hate when simple stuff kickes my butt
so i rode it yesterday (thank god it still runs) and im not too sure its a little slower, it does take off easier tho
i know when im ready to make it faster i felt some sharp edges i could fix and polish the intake...
 

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Ninja Racer
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2,767 Posts
Discussion Starter #15
finally got the bike more manageable for the kids
the throttle will only open halfway so he isnt scared of the power now
this is the third session, second go-out, i made him run the course both ways and it was my wife who requested the number 11, i just realised after that is spies new number

‪naythuns third session midway.MOV‬‏ - YouTube
 
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