Details of Crankcase nuts and bolts needed


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Downham Market
Hey Guys,

Planned to do a dry fit of Crankcase halves today to make sure i had every seal, Nut and bolt to hand - it seems I have bolts, nuts and washers missing!

All studs are correctly in place, what i need to know is the following:

1. Using the numbering scheme, which are the 6 nuts that should have domed nuts and sealing washers (Copper?)
2. I have 4 bolts that look to be the Crankcase ones, but are all the same size, only long enough to fit one hole - can anyone advise the correct size of all 4

Even with the XS650 Engine book and a magnifying glass its impossible to see what is what

Appreciate any help on this, I can get hold of the bolts/nuts from fastner suppliers, but its not something i want to get wrong and posible wreck the engine through oil loss or a slightly long bolt


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First thought was, "He must not have the Pahl engine book." I apologize for that, Barrie! When I opened Pahl to p.89 and looked I found just what you did--an undersized photo in which I couldn't distinguish domed nuts from open hex. It took me by surprise. Herr Pahl is usually meticulous in his photography and assembly instructions. I'll work on forgiving him for being not quite perfect. The thread to which Signal referred you has it all, with clear photos.
You can get the bolt lengths out of the part numbers. On many of the bolts used on Yamahas, the center number in the part number gives you the bolt size and length. Here's a crankcase parts diagram .....

The 4 bolts across the back are #15 - #17. Let's use #15 as an example. The part # is 97013-08075-00. The center set of numbers, "08075", tells you this is an M8 bolt that is 75mm long.
Thanks Guys,
perfect thread for the location of the domed nuts and same for the partzilla link ( I have used CMSNL) but never knew that the number referred to the size
Cheers guys, onwards and upwards!
The Factory Service Manual shows exactly where the six acorn nuts with copper washers go.