Valve Adjuster lock nut damage/overtorque
Joined: Jul 2013
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I went through this. Had to end up replacing a few rockers like 5 years ago. My cylinder 4 exhaust jam nut and screw were seized on the rocker at .012" clearance. I could loosen it but not tighten beyond that. It locked in place so I just left it. Worked fine until cylinder 2 went down.
Joined: Oct 2009
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From: Ontario Canada
I used my 3/8ths torque wrench on these jobs for a dozen years on multiple Hondas and never ran into an issue, including the S2000. I do tighten them first hand- snug , then I do the final torque with my 3/8th's torque wrench. I guess I should count my blessings.
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Joined: Apr 2020
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first i just want to thank all the prompt help to a newcomer with novice wrenching...i keep hearing s2ki is a superb community (i come from clubrsx, honda-tech and miata.net) and you guys are already living up to that
ok so update: i'm lucky enough to live close to a honda power sports dealer..they had locking nut part no. 90206-pto-004 which apparently is a direct fit according to HPN https://www.hondapartsnow.com/genuin...6-pt0-004.html
the parts guy who was quite knowledgable chuckled that I used a torque wrench and suggested to just hand tighten to no more than 1/4 turn past snug
how critical is it to get the torque perfectly to factory specs? my understanding is the rockers don't move as fast as the crankshaft?
if critical can you guys recommend an affordable (since rarely used) 1/4' torque wrench for using under the hood? many seem to suggest crow-foot so you can keep the adjustment still
honestly i was just using it incorrectly...i probably could've gotten away with it even though it's not ideal
i see it's a common mistake on forums
https://www.s2ki.com/forums/s2000-un...stment-840632/
https://honda-tech.com/forums/honda-...screw-2190053/
wow i dont know how i missed that in the service manual..7x0.75mm that's pretty unique?
the legendary billman chiming in (appreciate the shipping offer)
the adjusting screw upon closer visual inspection looks OK, the replacement nut went on with some occasional resistance but hand snugs fine @ the targeted 0.08" clearance
ok so update: i'm lucky enough to live close to a honda power sports dealer..they had locking nut part no. 90206-pto-004 which apparently is a direct fit according to HPN https://www.hondapartsnow.com/genuin...6-pt0-004.html
the parts guy who was quite knowledgable chuckled that I used a torque wrench and suggested to just hand tighten to no more than 1/4 turn past snug
how critical is it to get the torque perfectly to factory specs? my understanding is the rockers don't move as fast as the crankshaft?
if critical can you guys recommend an affordable (since rarely used) 1/4' torque wrench for using under the hood? many seem to suggest crow-foot so you can keep the adjustment still
I don't see how you can strip a nut at 14lbf. Nor how you can get an ordinary torque wrench on the nut with a screwdriver holding the screw firmly but I digress. 
Only notation I see in the service manual (page 6-10) has an arrow pointing to the nut (I assume) with "7 x 0.75mm" notation. A standard nut size.
-- Chuck
Only notation I see in the service manual (page 6-10) has an arrow pointing to the nut (I assume) with "7 x 0.75mm" notation. A standard nut size.
-- Chuck
i see it's a common mistake on forums
https://www.s2ki.com/forums/s2000-un...stment-840632/
https://honda-tech.com/forums/honda-...screw-2190053/
wow i dont know how i missed that in the service manual..7x0.75mm that's pretty unique?
Is it only the nut that is damaged?
Take a good nut from another rocker, thread it onto the adjuster. This will determine if the threads are ok on the adjuster itself. The nut needs to turn completely free with ZERO binding.
I’ll send you a nut but the adjuster needs to be checked first.
Take a good nut from another rocker, thread it onto the adjuster. This will determine if the threads are ok on the adjuster itself. The nut needs to turn completely free with ZERO binding.
I’ll send you a nut but the adjuster needs to be checked first.
the adjusting screw upon closer visual inspection looks OK, the replacement nut went on with some occasional resistance but hand snugs fine @ the targeted 0.08" clearance
Joined: Oct 2019
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Side note: I did my first valve adjustment today on my stock 2007 with 65K. I'm sure I'm the first person in there based on how stuck together everything was. My valves were WAY out of adjustment; on about half I could only get the smallest feeler gauge in there (.127).The other half I couldn't get anything through. There was a distinct change in engine sound, and I noticed an occasion metallic rattling noise was gone. This sound only occurred at high RPM; like 6k+. Pretty sure this noise thing isn't placebo. Any idea what that sound was, and is it possible to damage the motor with valves that tight?
Joined: Jul 2013
Posts: 5,731
Likes: 632
Side note: I did my first valve adjustment today on my stock 2007 with 65K. I'm sure I'm the first person in there based on how stuck together everything was. My valves were WAY out of adjustment; on about half I could only get the smallest feeler gauge in there (.127).The other half I couldn't get anything through. There was a distinct change in engine sound, and I noticed an occasion metallic rattling noise was gone. This sound only occurred at high RPM; like 6k+. Pretty sure this noise thing isn't placebo. Any idea what that sound was, and is it possible to damage the motor with valves that tight?
Joined: Jul 2014
Posts: 13,830
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From: Chesterfield VA
0.127mm is roughly half the clearance needed but (hopefully) it allowed the valve to close.
Intake: 0.21 - 0.25mm (0.008 - 0.010in)
Exhaust: 0.25 - 0.29mm (0.010 - 0.011in)
Setting the exhaust valves a "1000th over" (in inches) is a common recommendation and allows for the self tightening effect. No power loss. This would be 0.012in (0.30mm).
The '06 and later DBW cars are notorious for tight valves and they tighten in use. Tight exhaust valve will burn and not seal properly. If in doubt do a compression and leakdown test.
-- Chuck
Intake: 0.21 - 0.25mm (0.008 - 0.010in)
Exhaust: 0.25 - 0.29mm (0.010 - 0.011in)
Setting the exhaust valves a "1000th over" (in inches) is a common recommendation and allows for the self tightening effect. No power loss. This would be 0.012in (0.30mm).
The '06 and later DBW cars are notorious for tight valves and they tighten in use. Tight exhaust valve will burn and not seal properly. If in doubt do a compression and leakdown test.
-- Chuck
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Joined: Jul 2002
Posts: 22,386
Likes: 1,837
From: Long Island, New York
Side note: I did my first valve adjustment today on my stock 2007 with 65K. I'm sure I'm the first person in there based on how stuck together everything was. My valves were WAY out of adjustment; on about half I could only get the smallest feeler gauge in there (.127).The other half I couldn't get anything through. There was a distinct change in engine sound, and I noticed an occasion metallic rattling noise was gone. This sound only occurred at high RPM; like 6k+. Pretty sure this noise thing isn't placebo. Any idea what that sound was, and is it possible to damage the motor with valves that tight?
With half of yours being at .005, and the others at likely .002-.004, check them again in 15k miles.
Joined: Jul 2013
Posts: 5,731
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Frankly you shouldn't even use a torque wrench on those jam nuts. Just get them snug, the jam nut tool is strong enough to strip the crap out of the jam nut. You can tell the torque spec by the grunting noise you make tightening it, these guys don't take more than a sharp exhale. If you full on grunt you done made an oopsie and not just in your pants.
