What grade are the clutch spring bolts?

[MrAtom]

I broke one of them because I guess the last person who used this torque wrench in the autozone loan-a-tool program broke it and I didnt check to see if it was working before I used it. Anyone know what grade they are?

[fuel664]

i have no clue what grade, i am curious if there even is a down side to using grade 8, except for cost. in my area grade 8 is only a few cents more than a 5

[Ghostt]

No clue, sorry.

[fast1075]

American grades such a "5" and "8" do not apply to metric bolts. Metric has it's own similar sounding system.

The bolts are most likely 8.8 as marked on the bolt head. If they have no markings, they are ungraded, or roughly equivalent to American grade 3.

You should be able to find graded bolts at any auto parts store, or at any Lowes, or Home Depot, or Ace Hardware. You can also use the black socket head cap screws (AKA "allen bolts"), which are of a fairly good grade.

[Ghostt]

You guys need to either stop torque everything, of go out and buy a quality torque wrench.

[Ghostt]

Or lay off the steroids

[Motofool]

Originally Posted by MrAtom

I broke one of them because I guess the last person who used this torque wrench in the autozone loan-a-tool program broke it and I didnt check to see if it was working before I used it. Anyone know what grade they are?

Sorry to read about this mishap.

Inspect the head of your broken bolt for a JIS mark, which could be 7, 7T, 8, 8T, 10 or 10T.

Then, for ISO Metric equivalent bolts, check this link out:
http://forums.ninja250.org/viewtopic.php?p=853294

You may want to loose the other over-torqued bolts and re-torque all properly.
Torque wrenches at Harbor Freight may be not too precise, but are cheap and you can always verify how much their reading is off.

http://www.harborfreight.com/catalog...=torqur+wrench

https://www.ninjette.org/forums/showthread.php?t=176453

https://www.ninjette.org/forums/showthread.php?t=111031

[Ghostt]

Personally if your going to use a torque wrench, invest in a high quality one, I use a Craftsmen

[MrAtom]

@Motofool, helpful as always, but my bolt doesn't say anything on the head. There's a dot in the middle, but that's it.

[Mountain Dew]

Why not get one from the dealership?

[MrAtom]

Originally Posted by Mountain Dew

Why not get one from the dealership?

I have a beef with my local kawi dealer and I refuse to buy from them or Napa auto parts.

[Motofool]

Originally Posted by MrAtom

@Motofool, helpful as always, but my bolt doesn't say anything on the head. There's a dot in the middle, but that's it.

Because of that and how easily it broke, we can assume that it was made of low carbon steel.
Is it possible that the PO replaced the original ones with those?

Those bolts don't need to be super-strong: all the load that they stand is the one coming from the fully compressed springs.

I would replace all with similar dimensions of at least moderate strength steel (tempered medium carbon steel Class 8.8).

These links may help you:
http://blog.chiltondiy.com/2013/12/h...d-sae-bolts-2/

https://www.boltdepot.com/fastener-i...ade-Chart.aspx

https://www.boltdepot.com/fastener-i...ead-Pitch.aspx

[MrAtom]

Originally Posted by Motofool

Because of that and how easily it broke, we can assume that it was made of low carbon steel.
Is it possible that the PO replaced the original ones with those?

Helpful links, as always. I don't think it's probable. The PO didn't even change his own oil. He took it to a shop for all maintenance. Maybe she shop did, but it's unlikely.

I'll head down to the hardware store and try to find one with the same pitch and whatnot.

Again, thanks a bunch.

[dcj13]

Originally Posted by MrAtom

I have a beef with my local kawi dealer and I refuse to buy from them or Napa auto parts.

We should all be mindful about getting into tiffs with folks who can provide things for us, whether those things be material, information, assistance, or friendship.

[MrAtom]

Originally Posted by dcj13

We should all be mindful about getting into tiffs with folks who can provide things for us, whether those things be material, information, assistance, or friendship.

I choose my enemies wisely, thank you.

[ninjunk]

why would you not just go buy the best bolt that you can?

Be mindful of the head, if it is a flanged head bolt be sure you replace with a flanged head bolt. most of the time those are grade 10.9 flanged.

yeah, see
http://www.partzilla.com/parts/detai...2001-1066.html

those are flanged, that flange is pretty important, not just on there for looks.

NOW... they list 6x18 in the kawi catalog. Those posts are blind so there COULD be a clearance issue, probably wont be, but could be. That is not a common size although kawi uses it all over the place (IE, the fairing bolts which break through the tank if you use 6x20 instead of 6x18)

With that word of caution, you could use THESE from fastenal:

https://www.fastenal.com/products/de...ength:161500|~

but the risk of it bottoming out... if you are smart enough to know the difference between bottoming out, and you have the tools to cut 2 mm off the bolt, you could take a gamble on the fastenal ones and save 10 bucks (on a whole set, plus you get them quicker)

if you only want to replace one, or you're not sure of your skillz (you did break it off in the first place after all) just buy the ones from partzilla and tell your local dealer to pound sand.


I'm with ya on boycotting business that suck, its the only way they get better. I also usually write a polite letter to a manager.


On the torque wrench debate, I am not generally a tool snob but i am a torquewrench snob. I have 2 300+ dollar snap on wrenches, both of which i got out of the trash (literally) that are calibrated to NIST standards and traceable.

That said.. i got into this with a buddy of mine a couple weeks ago, he has
THIS TORQUE WRENCH FROM HARBOR FREIGHT we took his $9 (on sale) harbor freight torque wrench and hooked it up to my $300 snap on, his was reading within 1/2 in-lb from mine across the board. I was dumbfounded, and I have no problem admitting that I was wrong.

Either way the worst torque wrench is no torque wrench. If you plan on working on your bike you really need to have it, its worth 20 bucks any day of the week.


The clutch bolts aren't very heavily stressed but they are super important. I worked on a dirtbike where they backed out and it was pretty much a writeoff engine wise. Chewed up the clutch cover/cracked, metal debris through the entire engine, clutch basket mangled, not a pretty sight. The ninja being four stroke would pump that debris into the top end so you can add cam journal and connecting rod/bearing damage to the list... WOOF.

maybe put some loctite on those little guys while you're at it, i always do!

[Ghostt]

No loc-tite!!!!!!!!!!!

[ninjunk]

Really? why?

haven't had the ninja one apart, but most dirtbikes have the pre-installed loctite 'patch' on those, lots of racers safety wire them.

ok wow, i just did some checking to see if those come with the loctite 'patch' pre applied.. they don't , but they have a special little integrated washer thing...

As seen on ebay

Yeah i take back what i said about the fastenal thing, you better get the real deal, that is probably pretty important.