Getting correct nuts and bolts

[Jimmygixxer]

I have stripped the engine out of the bike. A few bolts had to be roughly persuaded out and a few maybe missing.
Whats the easiest & cheapest  way to measure the correct thread sizes etc and get good quality replacements that wont rust up in a few months?

[darrsi]

Obviously depending on how many you're on about to make things cost effective, you can buy originals on the AJ Sutton website, they're generally a couple of quid each but at least they were made for the job!
Just put your bike in the search box and then have a look at the drawings in detail.

[Lazarus]

was a company I used before (stagonset) that seemed to have gone through some "difficulties"

apparently some of the people have split and set up on their own :

http://www.westfieldfasteners.co.uk/

Stagonset were very reasonable and very quick delivery

you could also try
http://www.inoxbolt.co.uk/zen/
or
http://www.boltmeup.com/

[69oldskool]

Fag packet bolts lesson for "dummies":

When ordering bolts:
measure required bolt's length in mm(shank only unless its a countersunk bolt) as this is way bolt lengths are specified.
measure dia (of shank)~ 5mm="M5",6mm="M6" etc

so a 40mm L x 6mm D is a M6x 40 bolt.etc etc.

bolts up to & including m8 generally only available in a standard thread pitch unless you really go looking, so should be fine buying these pretty much anywhere.
m10 & over with Yamaha motorcyles use "metric fine"pitch bolts,DONT USE A STANDARD M10 BOLT!!
It's handy to have a thread pitch guage to be sure~cheap enough to buy,borrow or steal.

M10 x1.25mm  pitch is normal for yamaha, eg caliper mount bolts.I forget what the pitches are for larger bolts.
Choice of material is up to you, stainless don't rust but the threads generally don't look so well cut as their rusting cousins.
IMO avoid aluminium bolts unless you enjoy using a black& decker drill & swearing a lot   

Do bear in mind safety critical bolts such as caliper mount bolts should really only be replaced with bolts of the same or higher Tensile strength.
standard grade stainless bolts are not as strong as the standard high tensile steel ones!~ personally i doubt they'd fail in practice on a street bike?... but don't say i didn't warn you!

One final thought, when reassembling~ copper grease on the thread is you friend!
Next time you do the job it'll be SOooo much easier.

Hope that made some sort of sense, it's past me bedtime.