I know everything can't be correct but to the best of my knowledge everything is. Until it isn't. When I attempt to install the cover there is about a quarter inch between the cover and the crankcase. I also think I have the correct crankshaft cover. As you can see from the pictures the distance collar on the tachometer gear isn't level with the crankcase but on the engine cover, the hole where the drive gear axle is level with the face of the cover. Anyone run into this before?

Are you saying that the white plastic gear is not allowing the cover to fully seat against the crankcase?

Here is the 1974 DT360 tach diagram.... do you see any differences?

Yes, the white plastic piece is keeping the cover from meeting the crankcase. I also looked at this diagram and I don't see any difference from my installation. I removed the plastic piece and the cover fits flush with the crankcase. I took this engine apart 2 years ago and when I started to reassemble I couldn't find the plastic spacer. I assumed I lost it so I ordered another spacer.

Did you pull the gear off and look behind it?

I can't be sure, but it LOOKS like the kick idler gear is not flush with the kick gear. It looks like it is setting out too far.
I don't know if that is related, but it is noticeable.

I haven't pulled the tachometer gear and looked behind it yet. I also noticed the kick idler gear wasn't aligned and posted about this some time ago questioning why this might be so . I had taken pictures of this engine before it was disassembled and noticed those original pictures also showed the offset. The cover appears to be correct.

When you said you lost the spacer and said you had to get a new one, first thing I thought of is maybe the spacer was never lost?? Maybe it never had one in the first place? Yamaha literature is famous for mistakes, and this could be one of them?

Here's a link to mdscott's excellent restoration thread... no spacer.yamaha-enduros.com/index.php/forums/rest...dt360?start=50#55506

Here's a picture from the Yamaha Service manual... no spacer. I looked through the DT360 manual and there are several pictures that show the tach gear... none of the actual pictures show the spacer and you can see that the gear looks about the same height as yours... just no spacer.



The DT360 was a "one year" model... looking at pics of the 75 DT400 service manual, there appears to be a spacer... but there is definitely more shaft sticking through. Here's a picture from the DT400 manual... looks like the spacer is there but notice shaft length.



So my opinion is the DT360 diagrams are wrong and that model does not take the spacer.
(Just remember, my opinion is worth exactly as much as you paid for it.)






.

If it's ok with you guys, I'll play Robin to MarkT's Batman here!

Please find attached a scan from the relevant pages of my hard copy DT250A and DT360A parts manual (it's for European models, but that shouldn't be relevant here). Look closely, and you'll see that it's only the 250 that has the collar fitted.

Sorry, but you'll probably have to save the picture and then rotate it through 90 degrees.

Crackin' detective work on your part Mark!

Thanks for all the help and yes you're right, the DT360 doesn't use the spacer. I disassembled to verify that I installed everything correctly, and I had. The picture shows that with a straight edge held against the engine case the tachometer gear is level with the edge of the engine case. Again, thanks for the help.