YFZ Central banner
1 - 17 of 17 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter · #1 ·
i have a mostly stock 07 yfz 450 and im about to start doing some work on it but what is the stock bore/ stroke for this year? im looking to get a 13.1 piston along with alot of other things but i want to make sure i get the right one. i will be ordering my parts tuesday. i was also wondering, i was looking at this stroker kit that comes with the 13.1 piston is there any mods that would have to done in order to instal this, like any machining? how hard is it to instal a stroker kit? any one have some sort of guidlines, videos , instructions for me?
 

·
Registered
Joined
·
333 Posts
bore is 95mm stroke is 63.4mm if you go with a 13:1 piston if you go over 12:5 you will need race gas and if you go with a 3mm stroker crank it is going to raise your compression .5 so you compression would be 13:5
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #3 ·
QUOTE (adam00 @ Mar 1 2009, 09:01 AM) index.php?act=findpost&pid=752366
bore is 95mm stroke is 63.4mm if you go with a 13:1 piston if you go over 12:5 you will need race gas and if you go with a 3mm stroker crank it is going to raise your compression .5 so you compression would be 13:5[/b]
i already know i will have to use race gas theres a place right down my block its 8.99 a gallon i would rather run that anyway. but how involved is it to do a stroker crank?
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #9 ·
QUOTE (adam00 @ Mar 1 2009, 09:18 PM) index.php?act=findpost&pid=752629
this was my first time ever working on a 450 and i didn't use a manual and its way easier than a car motor[/b]
i was looking through my manual and it dont say nothing about splitingthe case. do i have to take the motor off the the quad or can i do it when its still on there? and it says i need a piston pin puller? and it dont say what to gap he rings at, in my opinion this manual kinda suck
 

·
Registered
Joined
·
2,724 Posts
Owner's manuals will not tell you how to do things like that, you'll need a service manual. To split the cases you will need to remove it from the frame. You do not need a piston pin puller. The service manual will give you all the specs on gapping.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #11 ·
QUOTE (Sidewinder @ Mar 5 2009, 02:31 PM) index.php?act=findpost&pid=754151
Owner's manuals will not tell you how to do things like that, you'll need a service manual. To split the cases you will need to remove it from the frame. You do not need a piston pin puller. The service manual will give you all the specs on gapping.[/b]
i have the servise manual it just came in two days ago and it dosnt say that i have to split the case to replace the piston im not doing the crank just the top end it say's to remove the head and the cylender but nothing about spliting the case, why would i haveto? and liker i said i didnt see any place that said what to gap the rings at, its showes you where to position the rings but thats it.


ok i found the gaps but it dosnt say anything bout removing the engine first or spliting the case.
 

·
Registered
Joined
·
2,724 Posts
QUOTE (450kidd @ Mar 5 2009, 12:36 PM) index.php?act=findpost&pid=754170
i have the servise manual it just came in two days ago and it dosnt say that i have to split the case to replace the piston im not doing the crank just the top end it say's to remove the head and the cylender but nothing about spliting the case, why would i haveto? and liker i said i didnt see any place that said what to gap the rings at, its showes you where to position the rings but thats it.


ok i found the gaps but it dosnt say anything bout removing the engine first or spliting the case.[/b]
Sorry, I never read the original post, I assumed you had to split the cases for whatever reason. No, you do not have to split the cases for a top end rebuild and therefore do not have to remove it from the frame.
 

·
Premium Member
Joined
·
3,989 Posts
You stated you thought about installin a "stroker" kit in the original post.

This would mean changing the stroke of the crank which would involve splitting thecases in half to access the crank assembly.
 

·
Registered
Joined
·
140 Posts
what about the oil squirter on the 07 clearing the piston with the stroker setup?
 

·
Premium Member
Joined
·
3,989 Posts
Yes, when using a CP piston which have a "X" web casting on the bottom side combined with a HotRods stroker crank, this causes the squirter to make contact with the webbing.

I read that CP was gonna work around that issue by offereing a different piston, but I don't know how accurate this is.

Also the squirter can be slightly modded at the tip to avoid this issue.
 

·
Registered
Joined
·
38 Posts
Discussion Starter · #17 ·
i was looking in to doing a stroker but did not have the money to go for the stroker at this time so i only went for the top end
 
1 - 17 of 17 Posts
Top