Post new topic Reply to topic  [ 18 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: CFmoto 250 decking the head
PostPosted: Wed Oct 29, 2008 10:12 am 
Offline
Buggy Enthusiast
User avatar

Joined: Fri Dec 14, 2007 3:29 pm
Posts: 239
Location: Marietta GA
Has anyone decked their head? I'm doing a top end rebuild and I was going to deck my head .0010, it should give me more compression.

_________________
SEMBRA.ORG if you like to ride in the South!
Riding Dirty That's How We Roll
http://www.youtube.com/watch?v=PMD_-pYdroo



Now Riding A 2008 Polaris RZR, Yeah Baby!


Top
 Profile  
 
 Post subject:
PostPosted: Wed Oct 29, 2008 10:16 am 
Offline
Sponsoring Dealer
Sponsoring Dealer
User avatar

Joined: Tue Jan 24, 2006 7:18 am
Posts: 8234
Location: Hampton GA
the cf moto engines are running around 10:2.1 compression stock. so if you deck the head you will have a lot more compression but also need to think about valve to piston clearance, cam chain slack.

_________________
Kinroad buggies,Carter buggy's, ams (manco) , joyner, parts for almost anything MRP dealer
Tucker Rocky Dealer
Vega Helmet dealer
I.T.P. tire and wheel dealer
http://www.mcdonoughpowersports.com


Top
 Profile  
 
 Post subject:
PostPosted: Wed Oct 29, 2008 11:39 am 
Offline
Buggy Enthusiast
User avatar

Joined: Fri Dec 14, 2007 3:29 pm
Posts: 239
Location: Marietta GA
all of those will be checked. Thanks BIGE!

_________________
SEMBRA.ORG if you like to ride in the South!
Riding Dirty That's How We Roll
http://www.youtube.com/watch?v=PMD_-pYdroo



Now Riding A 2008 Polaris RZR, Yeah Baby!


Top
 Profile  
 
 Post subject:
PostPosted: Thu Nov 06, 2008 5:17 pm 
Offline
Buggy Enthusiast
User avatar

Joined: Fri Dec 14, 2007 3:29 pm
Posts: 239
Location: Marietta GA
Well there is plenty of material that can be removed. The problem is the cam chain tensioner is to flemsy to take the slack out if you deck the head.

Is there an aftermarket cam chain tensioner or a smaller chain?

_________________
SEMBRA.ORG if you like to ride in the South!
Riding Dirty That's How We Roll
http://www.youtube.com/watch?v=PMD_-pYdroo



Now Riding A 2008 Polaris RZR, Yeah Baby!


Top
 Profile  
 
 Post subject:
PostPosted: Thu Nov 06, 2008 5:44 pm 
Offline
Moderator
User avatar

Joined: Wed Nov 28, 2007 1:21 am
Posts: 4044
Location: Seattle, WA
What about removing a link out of your current timing chain?

_________________
08 Joyner SandViper 250
07 Joyner SandSpider 650 - For Sale
06 Tank Urban Touring 150SE
04 Yerf-Dog Spiderbox 4209 GX150 (SOLD)
04 Yerf-Dog Spiderbox 3206 GX150
81 Honda Passport C70B

NW Riding - http://www.buggynews.com/viewforum.php?f=54


Top
 Profile  
 
 Post subject:
PostPosted: Thu Nov 06, 2008 6:33 pm 
Offline
Buggy Addict

Joined: Wed Jul 13, 2005 4:02 am
Posts: 2491
Location: Elburn Il.
From what u have posted .001 is not a whole bunch,check it out! Puty the head and find out how much clearence u have with the valves. 10:1 is a good ratio,Find another way to make more power .My opinion only.

_________________
_____________________
Karl



Blade DX 150*
* on the juice
Sunl 150(sold)
Quiksilver sr 440
150 kinroad racer- mods:its a secret


Top
 Profile  
 
 Post subject:
PostPosted: Fri Nov 07, 2008 3:47 pm 
Offline
Buggy Enthusiast
User avatar

Joined: Fri Dec 14, 2007 3:29 pm
Posts: 239
Location: Marietta GA
There's enough room to take alot more than .001 off. I need to find a smaller cam chain. Anybody no where to get one? Or if I can cut mine?

_________________
SEMBRA.ORG if you like to ride in the South!
Riding Dirty That's How We Roll
http://www.youtube.com/watch?v=PMD_-pYdroo



Now Riding A 2008 Polaris RZR, Yeah Baby!


Top
 Profile  
 
 Post subject: timing chain
PostPosted: Sun Nov 09, 2008 7:40 pm 
Offline
Buggy Dealer
User avatar

Joined: Thu Jan 11, 2007 9:30 pm
Posts: 43
Location: Roberta Ga
Cutting the chain would not be recommended. I would suggest finding out chain size, then counting links, do internets search and or call Honda and see if they have a diffent tentioner or chain? Maybe you will get lucky, but pushing the compression through the roof will mean the valve size needs to be increased.

Big E or Charlie might can explain that better, but by increasing the compression you are increasing resistance and keeping the same restricting the flow (intake and exhaust). This will shorten the life of your engine.

_________________
blade 150
4valve head, racing cdi
30mm carb w/dial-a-jet, 39 tooth sprocket
MRP Racing Exhaust



Blade ATV Dealer
Blade Parts Dealer
MRP Dealer
Hammer Head Dealer
Jackel Dealer
C & J's Extreme Powersports


Top
 Profile  
 
 Post subject:
PostPosted: Sun Nov 09, 2008 9:34 pm 
Offline
Buggy Crazed
User avatar

Joined: Wed Oct 26, 2005 6:05 pm
Posts: 1420
Location: Northern AZ
I have gotten into this with a few of you already, but this time I have had the compression measured at a shop so I am sure. My 250 is just a hair over 8 to 1 compression. Several of you have said your manual says 10 to 1, I didnt get a manual with my current machine, but the 250 I bought new which was a New Star said 8 to 1. I think you guys are taking a big leap assuming 10 to 1. What a turbo does is raise the compression by adding more air and gas, however the valves stay the same. Not to offend anyone but you guys are nuts. Raising compression is a very good way to add HP espesially since these machines are probably near 8 to 1 instead of ten to one and have along ways to go before detonation becomes a problem. If you can solve the timing chain issue you should make a big difference if there is room for 30 to 40 thousandths to come off.

_________________
2005 Joyner 650 Turbo, 8lbs boost
2006 Roketa 300 cc kit, clutch spring, uni and pipe
2006 sunl 1000
2005 Corvair powered 4 seater
2-1985 250sx trikes
2005 250 Joyner DD
6 Polaris Quads 90cc thru 400cc
1915 VW high jumper
Lots more small and large toys!


Top
 Profile  
 
 Post subject:
PostPosted: Mon Nov 10, 2008 12:55 am 
Offline
Buggy Addict

Joined: Wed Jul 13, 2005 4:02 am
Posts: 2491
Location: Elburn Il.
How about just maybe thinking of adding mat'l to the combustion chamber instead of milling the head there got to b away!The way the head looks they just did it so its one easy machine opperation.So you dont have to worry about cam chain.Or shim the cam up its running with bearings any way.Just thinking out loud,thats all.Right now I'm just a 150 guy but sooner or later I'm going to get a 250.

_________________
_____________________
Karl



Blade DX 150*
* on the juice
Sunl 150(sold)
Quiksilver sr 440
150 kinroad racer- mods:its a secret


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 18 posts ]  Go to page 1, 2  Next


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group

blackLevel designed by GrafsS



phpBB SEO