Hionda engine boilkts M6 with 8mm heads

[simon.d.hewitt@gmail.com]

Does anyone know where I can get the Honda engine case bolts M6 25mm long with 8mm heads, in black.
Thanks

[Oddjob]

Simon I'll tell you a trick for finding bolts like these.

It sounds complicated BUT as soon as you understand it you'll never look back.

Ok, Honda listed all parts which were identical like bolts with the same first 5 numbers.

In this case a M6 bolt with a 8mm head is always 96001.

The next 5 numbers were how long it was, so a 25mm bolt would be listed as 06025, which mean 06mm diameter and 025mm long. The length is always shown as 3 figures in case you want one over 100mm long.

The next 2 letters designated how it looked. Normally just 00 for a plain old silver bolt, as fitted to this day to most Honda engines. However IF you wanted a different finish you needed a different number. TBH I forget most of them now but a little digging found that a black bolt is 07.

So what you need are 96001-06025-07 which are still be orderable at any main Honda dealer or Fowlers for example. https://www.fowlersparts.co.uk/search/part/96001-06025-07

You want a different length, just change the 025 to whatever length you need.

This trick works on most Honda bolts. The trick is finding the first 5 numbers for the bolt type. Pretty easy if you know where one is fitted to start with.

Hope that helps. There are quite a few different finishes, like chrome or zinc plated or cadmium plated etc, a little searching can find them easily.

Oh and I forgot. Honda for some reason didn't just list standard size bolts, 20 and 25 are very common but 28 and 32 are not common yet Honda fitted loads of odd sizes like these. So IF you want a slightly longer bolt than 25mm try 28mm instead. There is normally around 5mm space under a casing bolt so a slightly longer one can be better especially if the thread is slightly damaged, the spare 5mm under will be pristine as it's never been used. Normally go up 2 on even numbers and up 3 on odd for some reason, so 20 has the next size as 22 but 25 has 28. Honda were very logical but a little odd.

[Orcade-Ian]

Ken,
That's a really useful piece of info for all of us who were baffled by what looked like a random system.  Could Steve put this somewhere where it's easy to find?

Thanks Ken,
Ian

[Oddjob]

That was the reasoning behind my rather comprehensive reply Ian. Sure I could have just listed the number and a link but that informs no one. If they understand how Honda used their part number system then they can use that info for other parts, all 5 digit front numbers are the same for the same type of parts, petrol tanks (17050), seats (77200), mudguards (61103) etc all share the same 5 numbers, it's the rest of the part number that changes to reflect the model.

So if you wanted to change all the casing bolts on your 550F for instance, you want to change them all to the more modern 8mm headed bolts instead of the standard JIS screws? Easy. Just find the length, work out the part number, type it into Google and see if Honda ever made one that length. They did BTW, as Grommitdog changed all of his for them on his 550 and they do look 100% better than the old fashioned screws. Plus you can use air tools to remove them or speed bars etc, you fancy black ones use 07 and see if they made them.

I used to do this all the time, I much prefer my 6 and 8mm bolts to be the flanged type, they look better IMO than a plain headed bolt, sometimes they have a washer underneath and sometimes they didn't. The code for a flanged bolt is 95700 and works for 6 or 8mm bolts. Maybe 10mm I've never checked. So for instance, why did Honda mix up flanged and non flanged on the rocker cover of the 500/550? why are some JIS screws? you can just as easily put a washer under a flanged bolt as a normal bolt and JIS screws don't torque down to well in my experience. So change them all to the 8mm headed ones, looks better PLUS the ones next to the tappet covers suit the 8mm headed ones better, they fit and don't foul the edge of the cover. Why did Honda fit overlength screws in those? the exposed threads rust and on removal can quite easily rip out the thread in the head, measure and buy the right length, no rust, more secure as you can apply slightly more pressure much easier etc.

The benefits are many, the only downside is the expense. Do like I do, search ebay for modern Hondas being broken, they'll sell you a job lot for next to nothing. Or visit your local breakers and get them even cheaper, they'll have buckets of them that they can't be bothered to sell.

I did know all the finish codes at one time, 02 is one and an additional A on the end like 00A is another. Chrome is something like Z. There's a list somewhere on the web. If this becomes a permanent tip we can add to the list as they are discovered.

[exvalvesetdabbler]

Only seen this one before, far from complete.

https://www.japanmotonuts.com/post/understanding-honda-fasteners-codes?currency=GBP

Perhaps you are talking yourself into a job here ken!

Regards
Dave

[K2-K6]

Nice detail Ken, and obviously very useful for buying replacement bolts.

My CBX 750 is native flanged 8mm in black. Although they did throw in a limited number of cap/hex fixings in places.

[Oddjob]

Never seen that list before Dave, interesting detail. I discovered the trick about 40 years ago, before the internet was born. Not sure how I noticed it but it suddenly became crystal clear how Honda were doing things. Maybe one of the partsmen gave me a clue, they could recite part numbers from memory.

I much prefer the current Honda casing bolts to the JIS screws myself. They don’t collect water in the slots if they face upwards for instance. Plus I could use my air hammer to take 10 of them out in the time it took to take one JIS out.

If nothing else it’s educated a few people. That’s always worthwhile.