piston change

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splashcroft
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piston change

Post by splashcroft »

hi all,
i was thinking of changing my kdx 220 back to a four stroke but have had so much fun on it the last few rides i have grown to love it.
i bought the bike last year and it has no history, i want to do a few mods, mainly suspension for my bulky holiday weight that seems to last all year.however i must priorities. i think i better change the piston out to be on the safe side.
ok now for the main questions,
basically how do i change the piston?
i intend to buy a wiseco piston and new rings to give myself piece of mind, however after reading the cyclepedia manual it only describes the whole engine dis-assembly. i'm pretty sure it can be made simpler to change the piston out. will the tolerances for stock be the same if i fit the new piston? i am also after a step by step guide to changing it if anyone has the time to jot it down. want to save a bit of dosh doing it myself and like to get to know the bike better by working on it myself.
alas one more question, running in procedure/ warm up before riding rather than just kicking and going with a wiseco?

thanks everyone
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diymirage
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Re: piston change

Post by diymirage »

once you have tackled the KIPS actuator it is all common sense and (IMHO) no instructions are needed
in short, you pull the head,, disconnect the KIPS actuator (support the rod and keep in mind this is lefthanded tread)
pull the jug off and you are home free

just to be clear, a new piston will include a new set of rings

just curious, where are you from ?
newbbewb wrote:DIYmirage has it right.


-1996 KDX 200 woods weapon (converted to 99 green body)
-1996 KDX 200 plated street toy (barney edition)
-2003 Yamaha TTR125-L (wifeys bike)
-1997 KDX 220 project bike
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Joshmcmillan
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Re: piston change

Post by Joshmcmillan »

Tolerances should be on the box when you buy the piston.

For run in, let it warm up, constantly blipping throttle at low revs, once warmed up (feel top of radiator and cylinder) then turn it off. Leave it a few hours. Repeat 3-4 times.
After that, warm it up, take it for a 15 minute ride just loading it up, never let it idle,,don't rev the hell out if it.
Cool it down. Warm it up, then take it for a ride and thrash the hell out of it.
07' CR450X (Main Bike)
07' KX125 (Completed basket case rebuild, for sale)
88' KDX200 (Not sure yet, runs but with rattly top end)
91' CBR250RR
Old Bikes: 97' KDX200, 00' RM125, 85' XR350, 94' KDX200, 02' CR80, 82' XT250, 98' CT200
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scheckaet
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piston change

Post by scheckaet »

check my sig for how to. there are a few key points you MUST pay attention to when removing the kips. :wink:
pumpguy
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piston change

Post by pumpguy »

As has been posted many times, do yourself a favor and GET A MANUAL. With one misprint about KIPS assembly, it has everything you will need to know about this bike.

One recommendation not shown in my manual is to install the wrist pin snap rings with their opening at the top or bottom. The idea being that when located this way, the opening will be in line with the reciprocating forces. If located at either side, these forces could cause the ring to close up, and possibly come loose. A remote chance I admit, but best not to take any chances.
splashcroft
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Re: piston change

Post by splashcroft »

thanks for all the advice. i'm from the uk. i have the cyclepedia manual but only really shows complete engine disassembly rather than just just what is required.
ok one last question. i am not sure if it has been re-bored having not stripped it down yet so don't want to get the piston yet. if i measure the diameter of the cylinder what should i allow for clearance?
diameter of cylinder - clearance = piston size required
cheers all
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