450r Piston Install ? Options

[SAND-KRAZD450R]

ok so im pretty good with a wrench but have always had 2 strokes so this 4 stroke crap is a little new to me. bought the gytr h.c. piston but am a little nervous to install it. can i just pull off the head of the motor(outside bolts), leaving the cams and valves and all that together, then pull off the cylinder. or do i have to tear down the entire head in order to do it? any info would help thanks...

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[wondernutz]

ok so im pretty good with a wrench but have always had 2 strokes so this 4 stroke crap is a little new to me. bought the gytr h.c. piston but am a little nervous to install it. can i just pull off the head of the motor(outside bolts), leaving the cams and valves and all that together, then pull off the cylinder. or do i have to tear down the entire head in order to do it? any info would help thanks...

you will have to pull the cams out to free up the timing chain

[lbyfz450]

you will need a repair manual for torqe specs and such, but yes you will need to pull the cams out, but dont have to touch valves or anything, its really easy to replace a piston, following step by step and taking your time, it will prob take between 2-4 hours from all together to all together again

[jon anderson]

easy to do ! make sure you ck the cam guides mine were wore & had to replace them , ck out kb motorsports on this site , they have new cylinders that are already bored.

[SAND-KRAZD450R]

thanks guys. removing the cam makes sense... im changing the intake cam to an 07 anyway(more top end) so no big deal. i know the piston itself is easy just was scared of the valves and guides and all the little stuff. hopefully get some good power out of this thing, of course in this game its never enough lol.

[DADDIO]

You will be leaving all the valves, springs, keepers, buckets, etc. in the head. Just remove the cam caps, then the cams.
BTW.......Stuff a rag in the cavity where the cam chain goes, before you remove the cam caps. There are two 1/2 circle clips that ride in a slot in the bearing, that usually sticks to the cap just long enough to lift it up, then drops down inside your motor.
Also, don't turn your head upside down, unless you support all the valve buckets. There are little shims under them used to adjust the valves that could come dislodged and screw up your valve lash.

[SAND-KRAZD450R]

thanks, knew bout the circlips under the cam caps from doing cam mod on my 07 but didnt know bout turning the head upside down. i mean i dont see why i would but nice to know not to.

[DADDIO]

Some people just like to flip the head over to look at the valves.

[YFZ God]

Well if you are replacing your intake cam you MUST check your valve clearence. If its screwed up your bike won't start. happened to me. I wasn't getting any compression because the intake valves werent closing all the way. thought I bent a valve but it just needed to be re-shimmed for proper valve clearence for the new intake cam. after that, fired right up.

This post has been edited by YFZ God: Nov 4 2009, 10:08 PM

[waters racing]

Heck, the hardest part is putting the clip on the wrist pin. Atleast it was for me the last two times. I don't know if someone has a trick for that. I ended up having pliers and a pick to get it in. Leave a towel in for that too so you dont drop that clip into the bottom end too.

[DADDIO]

Heck, the hardest part is putting the clip on the wrist pin. Atleast it was for me the last two times. I don't know if someone has a trick for that. I ended up having pliers and a pick to get it in. Leave a towel in for that too so you dont drop that clip into the bottom end too.

A small pair of needle nose pliers and holding my mouth just right always works for me.

[SAND-KRAZD450R]

yea the damn clip for the piston is a pain! took me longer to get that in then it did to tear down the bike lol. n e tips for getting the piston in??? fought it for like 15 min and ran out of patience after dealing with the clip...seems like a real pain in the a@@. opinions on break-in for the piston??

[YFZ God]

yea the damn clip for the piston is a pain! took me longer to get that in then it did to tear down the bike lol. n e tips for getting the piston in??? fought it for like 15 min and ran out of patience after dealing with the clip...seems like a real pain in the a@@. opinions on break-in for the piston??

I broke mine in like it was from the factory. 10 hours of riding it like it was new, then started haulin ballz.

Biggist thing is letting those piston rings set into the cylinder during the break in period. if you don't let them do that they may not seat right and you may lose compression (air getting past the pitson rings). so take it easy for about 10 hours then you should be fine.

This post has been edited by YFZ God: Nov 6 2009, 08:17 AM