PDA

View Full Version : yfz cam mod question


nkdurrett
02-18-2008, 07:44 PM
Hey i have a yfz 450 that has a no toil air filter,aftermarket drag pipe, and its jetted 170 and i heard the cam mod was the thing to do. So I had a buddy that has done the mod before do it to man but my quad wouldnt start. so we had to put the quad back the way it was. any clues y it wont work we only advanced the exhaust cam one tooth.
Ryan Plaugher
02-18-2008, 08:28 PM
i believe you retard the cam, not advance it. when i installed my hot cams i had the vavles a little tight and it didnt want to start.
lpmaster
02-18-2008, 11:33 PM
yeah, you're supposed to retard the cam 1 tooth i increased my pilot jet a size and it starts everytime. when its real hot it take a couple revolutions to fire but when its cold it fires RIGHT up
02-19-2008, 06:33 AM
I never had a problem with the cam mod. Not even with jetting to much. You sure he did it right ? exhaust cam 1 tooth clockwise?
nkdurrett
02-19-2008, 06:39 AM
yeah we took the cam one tooth clockwise and all we got was backfire. anything else maybe?????????
squadie
02-19-2008, 08:10 AM
Here's a link to a good post on the cam mod. See if you missed any steps maybe...

http://www.yfzcentral.com/invision/index.php?showtopic=59800
400exfan19
03-10-2008, 08:58 PM
i have a yfz with just white bros and no lid and its jetted correctly. If i put k+n on and do the cam mod do i have to rejet it?
ohsobad_chevy
03-11-2008, 03:08 PM
Originally posted by 400exfan19
i have a yfz with just white bros and no lid and its jetted correctly. If i put k+n on and do the cam mod do i have to rejet it?

Absolutely. Any modification that allows more air to your mixture, you will have to rejet. ;)
#17YFZRACER
03-11-2008, 04:08 PM
what the other matt said^:rolleyes:
400exfan19
03-11-2008, 10:06 PM
would it only be like one jet higher for just the cam mod and filter???
ohsobad_chevy
03-12-2008, 05:41 PM
Originally posted by 400exfan19
would it only be like one jet higher for just the cam mod and filter???

Each machine is different.....you will want to change the pilot and main for sure, you will most likely have to dial your fuel screw and need clip position as well. There are lots of jetting threads on this site to help ya out. Might search for them. ;)
#17YFZRACER
03-12-2008, 06:15 PM
maybe try a 170m and 48p, needle on 3rd or 4th clip and 2.5ish turns on the screw. just a suggestion it all depends on temp and altitude and such.:ermm: you will just have to play with it a little bit.
ohsobad_chevy
03-13-2008, 02:23 PM
Originally posted by #17YFZRACER
maybe try a 170m and 48p, needle on 3rd or 4th clip and 2.5ish turns on the screw. just a suggestion it all depends on temp and altitude and such.:ermm: you will just have to play with it a little bit.

That should get you close, the rest will have to be tuned in correctly.