No idea about the TF, sorry!

BUT on the other stuff

The LITTLE screws are indeed the drains. The Japanese discovered they could save money by not putting the drain screws in on later bikes... So you have to pull the forks and turn them upside down to drain.

Generally you would use the standard fork oil with the standard spring, perhaps bumping it by 2 1/2 to 5 max. E.g. if standard is 10W go to 12.5W or 15. (mix bottles of 10 and 15 to get 12.5)

You'll have to do a web search to find better springs, could be difficult. Try Progressive Suspension.

The stock springs aren't that bad when new. I raced a '72 TS185 in 72/73 with stock springs and they were pretty good for the time. Be sure it really is too soft - it's not too soft until it bottoms regularly! After a street bike ALL off-road bikes seem soft due to the longer travel suspension.

Ride it as is, it's a great bike for what it is. When you really NEED better, then buy a late model dirt bike, which will be MUCH better. Trying to modify the TS/TF to be as good as a cheap well-used 1990 or later real dirt bike is hopeless and ridiculously expensive.

They're super-reliable, almost impossible to break in stock or slightly modified form.

As for power, again it's good as is. You can clean up the ports - ONLY by someone who REALLY KNOWS what they're doing - and add a good expansion chamber, and that's really about it that's worthwhile. You might get super lucky and find a high performance head from Webco or a few others that made them in the 70's. There was a 175cc race kit available from Suzuki in the 70's, but I doubt you'll find anything now. And it wasn't good for trail riding, only MX.

Nigel hasn't left yet, it's still in the planning stages, but he's pretty committed!

Best of luck with the bike, and note that my suggestion is to spend more time riding it than messing with it!

------------------
Grant Johnson

Seek, and ye shall find.
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One world, Two wheels.
www.HorizonsUnlimited.com

__________________
Grant Johnson
Seek, and ye shall find.
------------------------
Inspiring, Informing and Connecting travellers since 1997!
www.HorizonsUnlimited.com