GZ 250 Forums - View Single Post

Pmhearns · 06-16-2017, 09:34 AM

Remove the side covers and look with a flash light if you have oil gathering in the pocket where both the spark plug is and the left front head stud are. If there is pooling there, youre likely leaking oil from the washer/gasket of the nut. DONT JUST TIGHTEN THE NUT! The BEST thing to do is now check for oil around the head gasket, if its clear... order the oem washers and gaskets for the head studs, And some quality grey gasket maker. Remove the valve cover, set it aside. Loosen(no need to remove completlly unless you are changing head gasket) the bottom nuts on the guide studs on the under side of the head, Now, remove each nut and the washer one at a time and MAKE NOTE of whether its a washer or a gasket. Then replace the used washer with the correct new one. I believe the gaskets (copper washer) go to the 2 studs inside the valve cover but not 100% sure.. i applied a small amount of low strength locktite to the inside of the nut... now finger snug 1 by 1 in cross pattern. The using a torque wrench, i tighten to roughly 20% of oem torque spec then cross to next stud and repeat in cross pattern until reached 100%. Then retorque the guide nuts... CLEAN ALL OLD GASKET RESIDUE FROM HEAD AND COVER. . I use methonal for this but alocol will work woth a fine grit scotch brite pad. Very fine bead of new gaset on cover and replace. Torqing bolts in same manner as head studs. It seems like a lot of work but abkut an hour and you will leak free for a long time

Also, it helps to replace those crappy stock header bolts with ss set screws... i think i used 30mm and they are 6x1.0 mm threads. I threaded them until they bottom out and back oit 1 full turn, then used lock nut to tighten them down that way you arent tightening up on the threads in the head..

If you DO have oil on the underside of the head, replace headgasket and repeat sll steps. And dont forget to mind the timing chain.... use a hammer to hold it up after you move the cam becsue if it drops, youre gonna have a bad time... also, buy new header gaskets.....

Phew...

06-16-2017, 09:34 AM	#5
Pmhearns Member Join Date: Jan 2017 Posts: 54	Remove the side covers and look with a flash light if you have oil gathering in the pocket where both the spark plug is and the left front head stud are. If there is pooling there, youre likely leaking oil from the washer/gasket of the nut. DONT JUST TIGHTEN THE NUT! The BEST thing to do is now check for oil around the head gasket, if its clear... order the oem washers and gaskets for the head studs, And some quality grey gasket maker. Remove the valve cover, set it aside. Loosen(no need to remove completlly unless you are changing head gasket) the bottom nuts on the guide studs on the under side of the head, Now, remove each nut and the washer one at a time and MAKE NOTE of whether its a washer or a gasket. Then replace the used washer with the correct new one. I believe the gaskets (copper washer) go to the 2 studs inside the valve cover but not 100% sure.. i applied a small amount of low strength locktite to the inside of the nut... now finger snug 1 by 1 in cross pattern. The using a torque wrench, i tighten to roughly 20% of oem torque spec then cross to next stud and repeat in cross pattern until reached 100%. Then retorque the guide nuts... CLEAN ALL OLD GASKET RESIDUE FROM HEAD AND COVER. . I use methonal for this but alocol will work woth a fine grit scotch brite pad. Very fine bead of new gaset on cover and replace. Torqing bolts in same manner as head studs. It seems like a lot of work but abkut an hour and you will leak free for a long time Also, it helps to replace those crappy stock header bolts with ss set screws... i think i used 30mm and they are 6x1.0 mm threads. I threaded them until they bottom out and back oit 1 full turn, then used lock nut to tighten them down that way you arent tightening up on the threads in the head.. If you DO have oil on the underside of the head, replace headgasket and repeat sll steps. And dont forget to mind the timing chain.... use a hammer to hold it up after you move the cam becsue if it drops, youre gonna have a bad time... also, buy new header gaskets..... Phew... Login or Register to Remove Ads Last edited by Pmhearns; 06-16-2017 at 11:26 AM.
	0