The original yamaha seat would be the most comfortable by far, the aftermarket units have seats not much better than a modern bikes sticker, very small & thin

To clean out your tank have a look at this thread

http://ozvmx.com/community/index.php?topic=14072.0

Couple of thoughts:

First if you ride on the street your Trials Tires won't last a month.

If you put street tires on it the bike is useless for Trials.

My personal choice for gas tank cleaning/coating is Caswells but I have also had good luck with POR15 - I would stay away from Kreem.

I never powder coat. You can paint yourself for almost nothing and if you are going to actually ride Trials it is going to get scratched up no matter what you use.

Sit on the bike as if you were riding on the street....and see where your butt is - I'm 5'9" and mine is on the back fender so putting a lot of money in a seat......

Just my personal choices.

Alan

Thanks for the replies guys. I have decided not to powdercoat for a couple reasons. First to save some money and second because I do plan on taking this bike offroad just as much as I plan on riding it on the road (not very much actually) Actually the money is a very important thing since the guy who rebuilt the crank used a YZ250 connecting rod as well and the crank that I had rebuilt is completely useless. The piston might actually be ok, but it's a moot point.. I guess I have a second crank to send out at least...

As far as the seat goes, the bike originally had the really big seat option, which I've heard came on the "CAT" version of the TY. Anybody have any more info. on this? Got a line on a brand new seat cover and still have the original base, but would need to source some foams to rebuild the seat and that will be a new experience which should be fun.

Thanks again guys, looks like the bike won't run until after the new year now but coming on here and reading these threads keeps me motivated.