Valve cover bolts

[fuelcat]

I found some Jis bolts at the hardware store that are the right size for my valve cover but do these bolts have to be made of a particular kind of metal?

[Steve]

No particular metal, but what is it about them that makes them "Jis"?

.

[tkent02]

Any old 6mm metric bolt will do.

[fuelcat]

jis

I dont know what makes them JIS or even what that really means but that is what the bolt was labeled. When I was working on my carbs getting JIS screw drivers were mentioned as a good idea to get because they fit the screws the best. So that was on my mind when I saw these bolts labeled as JIS

[tkent02]

Japanese Industrial Standard, like our SAE, it concerns the shape of the Phillip's head type screwdriver tip. The Japs didn't use Mr. Phillips's design, they used a slightly different shape. This is why cheap screwdrivers bugger up the screws so badly. The threaded part of the bolts are regular metric threads, AFAIK.

[bwringer]

On hex head fasteners, the JIS spec calls for a flange under the hex. This is the only real difference in the 6mm size. (Look closely at the original bolts on your bike.) You can also get these with a 10mm hex or 8mm hex. The 8mm hex is used quite a bit on later model Japanese bikes.

When you get to an 8mm thread, JIS calls for a 12mm head, rather than the 13mm head used on Euro (DIN spec) and 'merkin (SAE) metric fasteners. Random 13mm head fasteners are really annoying, but sometimes it can't be helped.

at 10mm and above, the thread pitches are different -- 8mm, 10mm, and 12mm threads in JIS are all 1.25mm pitch, while the "others" use 8X1.25, 10X1.5, and either 12X1.5 or 12X1.75.

I find this all really, really, really annoying -- can't we all just get along and agree on one worldwide spec for bolts?

And if you work on cars... ugh. Don't get me started on GM's fetish for goofy fasteners that require special tools, or Ford's unnatural attraction to Torx bolts made of Insta-Corrode(TM) brand cheddar cheese, used in the most random and inconvenient places.

[Baatfam]

I find this all really, really, really annoying -- can't we all just get along and agree on one worldwide spec for bolts?

Brian, you should try a WWII era BSA...
Quoted from my M20 forum:

...there are numerous threads used on the m20, british std whitworth BSW, british std fine BSF, british ascociation BA, british std pipe taper BSPT, british std pipe parrallel BSPP, british standard cycle BSC, and at least one ISO metric (m14 x1.5 spark plug).

Thank goodness you can still get the stuff...

[Killer2600]

On hex head fasteners, the JIS spec calls for a flange under the hex. This is the only real difference in the 6mm size. (Look closely at the original bolts on your bike.) You can also get these with a 10mm hex or 8mm hex. The 8mm hex is used quite a bit on later model Japanese bikes.

When you get to an 8mm thread, JIS calls for a 12mm head, rather than the 13mm head used on Euro (DIN spec) and 'merkin (SAE) metric fasteners. Random 13mm head fasteners are really annoying, but sometimes it can't be helped.

at 10mm and above, the thread pitches are different -- 8mm, 10mm, and 12mm threads in JIS are all 1.25mm pitch, while the "others" use 8X1.25, 10X1.5, and either 12X1.5 or 12X1.75.

I find this all really, really, really annoying -- can't we all just get along and agree on one worldwide spec for bolts?

And if you work on cars... ugh. Don't get me started on GM's fetish for goofy fasteners that require special tools, or Ford's unnatural attraction to Torx bolts made of Insta-Corrode(TM) brand cheddar cheese, used in the most random and inconvenient places.

They do it just to spite you

[fuelcat]

Well thats just nuts! LOL . Thanks for the explanation about the bolts ..learning new stuff every day

[fuelcat]

Gasket sealant?

On another note I had to remove the head because one of the bolts snapped off when I was removing it. I guess the last person that changed the gasket over torqued the bolts. The bolt was under the frame of the bike making it impossible to drill it straight out with the left handed drill. I got the bolt out but the threads got damaged. I got a tap to rethread the hole and I broke the tap off ...duhhh! So Now I am forced to take the head off I took it to a machine shop and got it fixed and it cost $100! So now I got The heads removed because I read that I better change the base gasket if I am changing the head gasket...OMG! I ordered all new o ring and gaskets, I cleaned and detailed the engine on the outside. I cleaned the carbon off the valves and the pistons. I did not take the pistons off. Mind you this is my first time wrenching and I had no plans to go this far but I am enjoying it so far. I just hope I dont F*** any thing up.
Question.... When I put the base gasket on do I need to use gasket sealant? I got Permatex RTV black. I can use any advise that you got to give me. I am going by the Clymer Suzuki books instructions but it said to install gasket but did not mention the sealant.

Thanks!

[koolaid_kid]

No sealant. All gaskets on your bike go on dry.

[fuelcat]

Thank you!

[John Kat]

On another note I had to remove the head because one of the bolts snapped off when I was removing it. I guess the last person that changed the gasket over torqued the bolts. The bolt was under the frame of the bike making it impossible to drill it straight out with the left handed drill. I got the bolt out but the threads got damaged. I got a tap to rethread the hole and I broke the tap off ...duhhh! So Now I am forced to take the head off I took it to a machine shop and got it fixed and it cost $100! So now I got The heads removed because I read that I better change the base gasket if I am changing the head gasket...OMG! I ordered all new o ring and gaskets, I cleaned and detailed the engine on the outside. I cleaned the carbon off the valves and the pistons. I did not take the pistons off. Mind you this is my first time wrenching and I had no plans to go this far but I am enjoying it so far. I just hope I dont F*** any thing up.
Question.... When I put the base gasket on do I need to use gasket sealant? I got Permatex RTV black. I can use any advise that you got to give me. I am going by the Clymer Suzuki books instructions but it said to install gasket but did not mention the sealant.

Thanks!

If you dismantled the cylinder block, it might be a good idea to hone the cylinders
As the piston rings will have most probably moved around you might be forced to put new rings on the pistons to avoid heavy oil consumption...
I'm not the absolute expert so please investigate further

[gearhead13]

I have heard horror stories about reinstalling blocks/old rings. I would recommend a light hone or glaze breakage with a fine grit hone.

[fuelcat]

ok I will do that. I dont really know what a hone or glaze breakage is? Do I take it to a machine shop? They charge $75-$100 an hr here.The cylinders and piston have no scratches on them. The engine was fine with no leaks before I was forced to take it apart because of the broken bolt.