Hey there! I've recently purchased a 2004 s2000 with 170k miles. Yikes, lots of miles !! I've encountered a few minor issues and I would like some help. Please forgive me, as I'm new to s2000s and roadsters.
1. Today I filled up a full tank at the gas station; however, my fuel gauge only reads 3/4 full. Any suggestions of how to tackle this issue? Remove the fuel pump and purchase a new gauge/pump or do i need to sand down the reading tick marks?
2. The previous owner installed an Invidia N1 dual exhaust (good god almighty, my ears are ringing after a cruise on the highway) and the cabin smells like exhaust fumes. Is this the consequence that comes with catbacks or is there an exhaust leak somewhere?
3. The car is still making a ticking noise in the engine bay ( i replaced the tensioner a week or so ago)? Is there something wrong with the timing? Could it be a driveshaft rattling?
4. In general, what are some tips for keeping the s2000s going? Can these cars run past 200k miles like other Honda's or is my s2000 coming to its end?

Thank you! I know these may be some amateur questions but I want to learn/understand/solve issues and other things that may come along my (hopefully years) of owernship. Cheerio!

 

Not sure about the fuel gauge its not too common on s2000, but you could be right...maybe just fill it up few times see if it gets better.
but that exhaust smell sounds like leak in the middle behind cat somewhere... look for black spot at the joint behind cat or if it has testpipe more likely the front joint with spring bolts.
Ticking noise sounds like valve clerances bit too loose...as valve clerance is almost number 1 thing to check after buying s2000 (and also at same time check valve retainers for CRACKs - note: hard to see, look for sunken keepers at the top of retainer best to do some online search what to look for). Then you will hear what it sounds like after adjusting them.

guide on adjustment: (https://robrobinette.com/S2000ValveAdjust.htm)

Otherwise change all the fluids (diff, gearbox) and clutch fluid. (also adjust clutch rod to "0" play to improve shifting and to save your 2nd gear as per billmans recommendation), then 'tighten rear axle nuts' to save rear bearings/hubs (especially if you hear click sound as you reverse or take off).... and enjoy her for another 200k miles

 

Sometimes the fuel gauge is slow and has to catch up. At least mine does. I fill up until the pump clicks off, then maybe squeeze the pump 1-2 more times (it'll click off very soon/quickly since it's already full), and I am still 2-3 bars empty on the gauge from Full. Then I drive off and the gauge slowly catches-up, and then becomes totally full, maybe 10-20 miles down the road...if that made sense.

 

Yes, these cars can easily run well past 300k miles like any other Honda, so long as nothing bad happens, like low oil. Speaking of which, check oil often to get a feel for usage, and be aware the dipstick can lie. Windage tray can drip onto dipstick, giving false high reading when oil is actually low. Always check both sides of stick and go with the lower reading.

The exhaust smell sounds like ot has a testpipe in place of the cat.

The ticking might be normal. These cars use mechanical valve lifters, which are noisier than hydraulic. You need to do the valve adjustment to be sure. Interestingly, often these cars get noisier after a valve adjustment, as if the clearances are too tight, its quiet. So perhaps the valves are just properly adjusted, hence noisy.

When you say replaced tensioner, do you meam the tct, or just the serp belt tensioner? If you haven't done so, replace tct with a Billman tct. That could be your noise.

 

I had the "quieter" Invidia Q300 on my car. For two weeks and only that long as the replacement Tanabe Medalion Touring took a week to ship from California to Ohio.

I put a Berk 63.5mm high flow cat in the middle. No stink. No earplugs needed. I'm happy, my wife will ride in the car again, and the neighbors are happy.

If you can get the car on a lift or high jackstands you can replace the Invidia in 30 minutes assuming it's not rusted in place.

-- Chuck