Kdx cylinder head torque pattern

[JZ05220r]

Hey guys, been awhile since I posted but I’m about to be finishing up with the engine on my kdx. Although the manual says to tighten in a cross cross pattern, with headgasket issues in the past, I’d like to know if their is a better method than the vague criss cross pattern suggested in the manual. I’m considering tightening around the cylinder bore first then the 2 toward the front of the engine. Obviously I’d go in a few stages. The head has been lapped to 320 and I cannot fit my .0015in ** gauge anywhere with a straight edge. The cylinder is lapped as well but with 220 grit. I believe that the oem coating should handle each surface finish.

[SS109]

This is how I do it. I also torque it in two stages. (Yes, I'm OCD when it comes to how I do things!) I do the pattern once at 10 ft-lbs and then follow it again as I finish torquing it to it's finals spec of 18 ft-lbs.

KDX torque pattern.jpg (101.36 KiB) Viewed 1783 times

[JZ05220r]

Thank SS109. This is how I will do it. I am dreading the moment where I check for bubbles under the cap after my previous experiences. I wanna blame it on the torque wrench. Using an oem gasket this time around and everything checks out flat. Are their any pros and cons with the oem vs the tusk/ nbr coated head gaskets?

[kdxdazz]

the OEM gasket has a sticky sealant on it which shouldn't be touched when installing and then if you try to reuse it the sealant has to be removed where as the viton/nbr gaskets seem easier to reuse,it seems most companies use viton now so i'm guessing that is the more superior product

just on torquing the head, the service manual states that torque measurements are for solvent cleaned threads so if you use any kind of oil you will need to slightly reduce the torque numbers, my guess is reduce it by 15 percent

in a previous post i talked about using copper head gaskets, i was unable to get mine to seal with the 1mm thick copper but after last week paying a visit to the well known keng kawasaki that produces klx250 big bore kits he told me he also had trouble sealing with 1mm thick gaskets as motorcycle studs are so small and can't be clamped down sufficiently to crush the copper, he said 0.8mm copper is better but now uses old school custom made fibre head gaskets

[JZ05220r]

I really do wonder it the oem gaskets are too fragile and can be damaged without even knowing during install/sliding over studs and torquing down. I plan to leave the threads dry for the cylinder nuts and lightly oil the other end.

[JZ05220r]

This is how I do it. I also torque it in two stages. (Yes, I'm OCD when it comes to how I do things!) I do the pattern once at 10 ft-lbs and then follow it again as I finish torquing it to it's finals spec of 18 ft-lbs.


KDX torque pattern.jpg

Dug up an old post from 2012 where you mentioned stock head and base gaskets are your go to. With all your experience with the kdx’s do you still stand by that?

[SS109]

This is how I do it. I also torque it in two stages. (Yes, I'm OCD when it comes to how I do things!) I do the pattern once at 10 ft-lbs and then follow it again as I finish torquing it to it's finals spec of 18 ft-lbs.


KDX torque pattern.jpg

Dug up an old post from 2012 where you mentioned stock head and base gaskets are your go to. With all your experience with the kdx’s do you still stand by that?

Yes, I do. Factory head gaskets have always worked for me with both stock and RB modded heads without issue. As evidenced by my Youtube vids, I don't take it easy on my KDX or any bike! I still prefer the OEM base gaskets as I do believe the material they use is of higher quality and density than the aftermarket versions I've had in my possession over the years.

[JZ05220r]

This is how I do it. I also torque it in two stages. (Yes, I'm OCD when it comes to how I do things!) I do the pattern once at 10 ft-lbs and then follow it again as I finish torquing it to it's finals spec of 18 ft-lbs.


KDX torque pattern.jpg

Dug up an old post from 2012 where you mentioned stock head and base gaskets are your go to. With all your experience with the kdx’s do you still stand by that?

Yes, I do. Factory head gaskets have always worked for me with both stock and RB modded heads without issue. As evidenced by my Youtube vids, I don't take it easy on my KDX or any bike! I still prefer the OEM base gaskets as I do believe the material they use is of higher quality and density than the aftermarket versions I've had in my possession over the years.

I once read putting a light coat of grease of the headgasket helps making sure everything falls into place nicely. Probably not a good idea with the oem headgasket I would assume.

[SS109]

I once read putting a light coat of grease of the headgasket helps making sure everything falls into place nicely. Probably not a good idea with the oem headgasket I would assume.

No clue. I've always installed them dry. I have even reused one once after spraying it with Permatex Copper Spray gasket. I think the factory gaskets are plenty tough.

[JZ05220r]

I once read putting a light coat of grease of the headgasket helps making sure everything falls into place nicely. Probably not a good idea with the oem headgasket I would assume.

No clue. I've always installed them dry. I have even reused one once after spraying it with Permatex Copper Spray gasket. I think the factory gaskets are plenty tough.

Ok, well I rechecked everything with a straight edge and the cylinder head is dead on. I was using a .04mm feeler gauge and found that when I put pressure on the exhaust side of the cylinder it opens up a big enough gap to let the feeler gauge slide through the intake side. When I center the pressure into the middle of the cylinder I can no longer fit the gauge. I left a pic for example. Hopefully this won’t be an issue. Red arrow represents where gaps are and green represents no gap.

[JZ05220r]

I learned that the subvalve guides for a 220 cylinder are 1mm taller. Found that the kips was completely locked when torquing the head. That’s why I’m concerned with the flatness on an otherwise brand new oem 200 cylinder,especially around the subvalve guide areas because it could have created warp. I’m going to try a more reliable straight edge like a precision parallel set and see what I get. If I’m not satisfied I’m going to pull the cylinder and lap it on my piece of granite. I’d use some non permanent adhesive spray to hold the sandpaper still and flat. Question: I have some layout dye and was thinking of coating the head surface and placing it on the cylinder to check for full contact. Is their a better method for utilizing the layout dye in my situation?

[kdxdazz]

I learned that the subvalve guides for a 220 cylinder are 1mm taller. Found that the kips was completely locked when torquing the head. That’s why I’m concerned with the flatness on an otherwise brand new oem 200 cylinder,especially around the subvalve guide areas because it could have created warp. I’m going to try a more reliable straight edge like a precision parallel set and see what I get. If I’m not satisfied I’m going to pull the cylinder and lap it on my piece of granite. I’d use some non permanent adhesive spray to hold the sandpaper still and flat. Question: I have some layout dye and was thinking of coating the head surface and placing it on the cylinder to check for full contact. Is their a better method for utilizing the layout dye in my situation?

layout dye is perfect for your situation, i made my own from tyre grease and blue ink, i really learnt alot from using it, what i thought was perfectly flat was not even close to flat, just remember granite is not perfectly flat,at least that has been my experience

[JZ05220r]

I once read putting a light coat of grease of the headgasket helps making sure everything falls into place nicely. Probably not a good idea with the oem headgasket I would assume.

No clue. I've always installed them dry. I have even reused one once after spraying it with Permatex Copper Spray gasket. I think the factory gaskets are plenty tough.

Fingers crossed for a good head gasket seal. Torque in two stages in the pattern that you mentioned. Although this wasn’t the problem cylinder, I had everything checked over by a guy at Millenium technologies.