After realising the interior of my tank was way too rusty and had previously been lined, all be it badly, I had to dissolve the old liner with Acetone and there was no way I could stop the existing paint being ruined 
 

Paint stripper applied and tank back to bare metal I could see the old repairs. Now filler/bondo and just getting the tank in some sort of good shape.

 
 

Next some etch primer.

 

Now I was wondering whether to paint where the petcock/fuel tap fits to the tank, my thinking was the fuel would be against the paint and maybe the seal wouldn’t seal. So I decided to tape the hole and primer and paint, then remove the masking tape and clear coat.





 

Some nice filler primer.

 
 

flatting the primer ready for colour.

 

Competition yellow, ready mixed.

 
 
 

After drying I had some sunken pin holes, so what did I do? Rubbed the area, filled, sanded smooth then thought I could just spray over the colour coat  .
What a rookie mistake, knob ed……..!

The whole area reacted  , I had to complete flat back and reapply the filler primer and had to purchase some more paint…….!

Anyhow, second attempt was perfect.


Then onto the 2K clear coat, and took the petcock area tape off.

 
 

 

After leaving for a few days I machined polished the whole tank, you can see the difference from the orange peel……..

 

to glass mirror finish  .

 
 

I was contemplating clear coating over the decals but thought originally Yamaha would of applied the decals over the paint, so went original, plus if they get damaged I can replace.
A local shop supplied the decals and I got the proper 400C as the previous owner had used the wrong ‘B’ ones.

 
 

Nice work!!! 

Thanks for sharing all the pics and advice!

(p.s..  the heat shield decal is also from the "b" model...  "c" model only said "enduro" on the oil tank and heat shield.)

Paint looks great, I’m getting ready to do a DT400C tank as well and was also wondering about painting the fuel petcock mounting area as well, from my research from the factory the petcock area was painted. One other note on your decals where the large black decal portion is placed on your tank it should be about 1/8-1/4” above the lower decal, you should be able to see the yellow between the two decals, hope that makes sense.

Thanks MarkT, you helpfully answered the question about differences some time ago, so I’ve got the side decals, plus the oil tank needs painting, it has some bad reaction holes in the paint and it’s a shade darker, so another winter job.

Thanks Lizeec , I’m not happy with the decals so lucky I didn’t clear coat over them. I had some old brochure pics of the 400C but that gap got past me  , good to know. Do you know if they were gloss? These are a matt, satin and they just do not look right.

Yes the whole tank I believe was painted, and thinking now, it wouldn’t really hurt around the petcock but I just overthink things  , most importantly, it doesn’t leak   .