I think we do for the most part. The weight was honestly one of the best investments I made to my 97YZ 250. Most other products were just a waste of money.
I notice improved tire wear with the weight in place. Wheelspin was reduced without a doubt.
If I could start over on my motor again I would buy the weight kit first, then send the cylinder and head to Eric for a Mo' better power everywhere port job.
I bought one of every pipe I could find on ****. I bought stock, FMF fatty and Gnarly, Pro Circuit, Noleen, and SPES/ Doma. Out of all the pipes the Noleen is the most fun to play with. It honestly gave the bike more low end. Top end is nothing. Almost like hitting the kill switch. Still, the low end burst is fun.
The Pro Circuit pipe and silencer were a giant dissappointment. The fit was excellent. The performance was less than stock. Very booring power dilivery. Zero low end.
The FMF stuff was ok. No real improvement, but no decrease. Fit was lousy. I ended up returning the fatty as it offered nothing extra except exhaust leaks.
I am running the SPES stuff right now. It is well built, it fits , and offers a wider powerband than anything else. Good stuff.
The weight set, however, is much more valuable than any of the pipes. The YZ feels like it should have been supplied with the 8 oz weight from the factory.