Hi - sorry for all the questions at the moment, but I'm trying to get my bike on the road and need some help....          All the videos/exploded diagrams of DT400B forks show a spacer (and a washer inbetween?) on top of the fork springs.          My forks don't have this spacer (or the washer).          The springs are approx 440mm, and when put into the tubes (with no loading - the forks are out of the bike) there is a gap to the top of the fork tube of approx 35mm, which is the same depth as the fork top bolt. So, there doesn't seem to be any room for a spacer?          Have my stock springs been replaced with longer springs and the spacers (and washers) thrown away? I'm guessing this is a possibility as the fork top bolts have been 'upgraded' to the type with a schrader valve in which air/nitrogen can be pumped in (thanks to MarkT for educating me on that one!)          Or do I indeed have stock springs, but need to buy some spacers (and washers)? I assume then I would have to compress the springs while inserting the fork top bolts?          Or, should I cut the springs down (if so, what length) and fit spacers (and washers)?          Or is it all ok like it is?          Any information is greatly received. Many thanks   

Normally there is preload on the spring, so yes, there should be a spacer.  The air caps probably had instructions to remove them because air was being added. 

 

You should be able to make your own spacers and find proper size washers if someone here can give you the dimensions. There is really nothing special about those pieces. I have the same bike, but it is tucked away in my barn for the winter, so hopefully someone has easy access to check those dimensions for you. If not, I can try and get at it next weekend.

Common PVC pipe works well for a spacer material.

Hi - thanks once again. If anyone could give me all the dimensions of the spacer and washer that would be fantastic. 
From what I've gleaned off the internet, it looks like the washer is specially shaped to fit inside the spring and to keep things central...

Hi - it's just the spacer that I need the dimensions for.  Length, inner diameter and outer diameter (although they look pretty thin on the pics I've seen on the internet).  I decided to treat myself to two special shaped washers from the states.  Thanks in advance for the spacer measurements...

I said I would measure my spring spacers this weekend but forgot we are heading out of town. I can still do this, but it won't be this weekend like I offered. I will check to see if anyone else comes thru for you when I get back on Monday. If not, I will pop the cap and get your measurements.

Thanks Schu. There is no hurry as I've had to take my forks to get them straightened!!!  
I have just bought some spacers from (I think) a DT400MX, hoping that they will be the same diameter, that I can cut down to length. They look like they are much longer than the ones on the DT400B. For the record, the ones I now have are 25mm OD x 74mm, part no 341-23118-50. Many Thanks....

I will take the spacer measurements tomorrow and post them here.

I took these measurements off my DT250B parts bike because it was easiest to get at in my barn without having to uncover my 400. The spacers are the same in both bikes.

Length is 1.53" or 39mm
Diameter is .98" or 25mm 
Wall thickness is .04" or 1mm

All measurements were taken with $2 vernier calipers which hold the highest value per dollar of any tool in my garage.